The Tex experiment has begun.

I am testing out a theory proposed by Tex's Ridge, that the Ridgeline gets better gas mileage on 89 octane mid grade gasoline than on 87 octane regular. I have always used 87 up to this point and I wanted to test his theory. If true, the ROI will be calculated to see if using 89 octane actually saves money.

Please note that this is being done with the best of intentions. I just want to see if it's true. Tex is a great guy and an equally great ambassador for this truck. It's not about proving anyone wrong.

The plan is to run one tank of 87 through my Ridgeline to establish a baseline, then two tanks of 89 octane for the test. I will fill up at the same, name brand station, to maintain consistency in the fuel and pricing.

I have completed the baseline tank, and filled up with my first tank of 89 octane.

First tank:

Vendor: Mobil
Octane: 87
Price of 87 octane: $2.039
Price of 89 octane: $2.149
MPG: 18.1

Note that my truck usually gets between 19.6-19.8 mpg during normal weekly driving. This is probably due to the winter switchover to RFG, which is usually around the beginning of November.

It may take several tanks and varied driving to get the computer retuned for the different fuel. Further as a better experiement you should reset the computer between fuel changes and then run serveral tanks through of each and monitor the mileage. And it should be on a vehicle that has had at least one oil change and preferebly right after the oil change. This will help insure the engine is broke in to some extent and there are no hinderances like old oil.

Below was my post on the thread "Good Gas Mileage" I wanted to copy it here instead of restating my first impression. I'm still pumping 89, and my truck still is running smoother than before 89. I've been topping off at half tank since ROC @ the Rock, and been averaging 15.5 mpg with 50/50 town and highway. Now the highway is very hilly (84 east). I don't think altitude is a factor, as someone suggested. My home in Manchester, CT is 52 feet above sea level. I had asked my wife to pump 89 only into her CRV. She has reported that her engine runs a lot smoother. I checked her last mileage ( last week), and did not see any improvement (23 mpg). Her travels are mostly highway (that same hilly highway 84 E between Manchester and Sturbridge, MA) Now, I do am attributing the deterioration of my MPG since the ROC @ the Rock, to the winter fuel. Beside all this, I intend to stay with 89, ($2.00 more per a 20 gal fill-up) if not only because of the smoother engine and better acceleration. It's too bad I did not discover this before the transition to winter fuel.

"OK here's my .02 worth. I went to the ROC @ the ROCK meet this past weekend. I decided to check how my truck would perform with 89 octane fuel versus the 87 I've been pumping. To my surprise, the engine runs smoother (no hesitation), it seems to have more power, and I gained 3 to 4 more miles to the gallon. I drove 578 miles on route 80>81>84. I was driving very aggressively, averaging 77 mph. I was passing traffic to 85 mph at 4000 rpm's. I filled up when I got home, and calculated 22 mpg. The thing that gets me, with the 2 extra octane, how the engine purrs, and how much perceived power increased. I don't think I'll ever use 87 again. I told my wife to use 89 on her CRV. With 89 octane, yes I pay 0.10 cents more per gallon. For a 20 gal fill up, that's 2 dollars more. If I get even just 2 miles more per gallon, at 20 gal, I would gain another 40 miles. So, if by paying the extra 2.00 dollars, the first 20 extra miles paid for that, the other 20 exta miles is a freebie."

I started my Tex Ex last week and am halfway through first tank. Trying to simulate last 87 tank driving style - mostly 15 mile one way commuter trip at about 40 miles per hour - stop and go with some 2-3 mile continuous between light runs. Welcome to Long Island surburban driving. I drained the last 87 right down to the empty line and took about 20 gallons of 89 on fill up. Last 87 tank was 16.5 mpg and that is about my average over first 4500 miles. I do not perceive any performance enhancement and my RL always seemed to run smoothly at 87 and continues to do so at 89 octane. Any good experiment needs a few results to take an average and minimize variable effects over the results so I expect to do this and take measurements for 1 month (About 4 fill ups).

I'm also trying the 89 octane. I started with the 87 and was averaging 15mpg city. Lets see what i get with the 89... :D

I just realized something, (my brain never stops) now that I have established, from the last two top off that my avg mpg is 15.5 with 89, I'm going to switch back to 87 to compare performance with the winter fuel.:) Will keep you posted. I do have to burn the full tank of 89 in the tank now. Hmmm, where can I go for a 400 mile drive:D

I just realized something, (my brain never stops) now that I have established, from the last two top off that my avg mpg is 15.5 with 89, I'm going to switch back to 87 to compare performance with the winter fuel.:) Will keep you posted. I do have to burn the full tank of 89 in the tank now. Hmmm, where can I go for a 400 mile drive:D

Ok, time to show my ignorance. :(

What is winter fuel? Do they add something to the fuel or something for wintertime driving?

Thanks :o

1st tank of 89, maybe 0.1 mpg better. On 2nd tank and will give it a 3rd tank of 89 before deciding. Driving carecteristics, might be smoother but it could be expectations.:rolleyes:

Ok, time to show my ignorance. :(

What is winter fuel? Do they add something to the fuel or something for wintertime driving?

Thanks :o
Yes they do! Like it or not.

Ok, time to show my ignorance. :(

What is winter fuel? Do they add something to the fuel or something for wintertime driving?

Thanks :o

Heres a link from a couple of weeks back
http://www.ridgelineownersclub.com/forums/showpost.php?p=41631&postcount=70

Heres a link from a couple of weeks back
http://www.ridgelineownersclub.com/forums/showpost.php?p=41631&postcount=70

Ridgester, I reread your post thru the link above. From what it said, CT is not one of the areas mandated to dispense only RFG?

Hi all,

I will give a couple of tanks of 89 a try.

I have check every tank for mileage and usually get a solid 19 and sometimes 20, rarely 17, 18, or 21.

I will let you know

I'm taking this test one step further. Absolutely giddy over the more affordable gas prices, I tanked up with 93 octane. I'll do the same ROI although I'm only 70 miles into the first tankful. I can comment that I think the slight hesitation we all experience when accelerating out of a turn seems to be less pronounced. I'm really looking for an improvement in mileage (averaging +/- 16 mixed used with 7000+ miles recorded and now running on synthetic oil).

Ok, time to show my ignorance. :(

What is winter fuel? Do they add something to the fuel or something for wintertime driving?

Thanks :o
good article about the subject
http://www.epa.gov/

I thought I remember reading somewhere, a few years ago, that the price difference vs performance increase of 87 octane vs 89 octane did not warrant paying the extra money. You would have to go to 93 octane to actually get your monies worth.

I tried googling it but came up empty. Maybe that was just a dream.

RidgeInTheVille

I thought I remember reading somewhere, a few years ago, that the price difference vs performance increase of 87 octane vs 89 octane did not warrant paying the extra money. You would have to go to 93 octane to actually get your monies worth.

I tried googling it but came up empty. Maybe that was just a dream.

RidgeInTheVille
A few years a go, gas was around a buck a gallon, so the difference from $1.00 to $1.10 was a 10% increase in cost which would require a 10% increase in gas mileage to break even. Fast forward to today, the same difference from $2.00 to $2.10 is only 5% difference, so you now only need a 5% increase in fuel efficiency to pay for the difference.

The problem is, I still don't know if you actually get better mileage or not.

I thought I remember reading somewhere, a few years ago, that the price difference vs performance increase of 87 octane vs 89 octane did not warrant paying the extra money. You would have to go to 93 octane to actually get your monies worth.

I tried googling it but came up empty. Maybe that was just a dream.

RidgeInTheVille

the shortcut below leads you to a statement within that proves you wrong, for one reason only. The anti-knock device that senses fuel burning and sends to the ECM. The RL has this system.
http://www.chevron.com/products/

the shortcut below leads you to a statement within that proves you wrong, for one reason only. The anti-knock device that senses fuel burning and sends to the ECM. The RL has this system.
http://www.chevron.com/products/
Since this didn't directly link the article, below is the actual quote:
Many newer vehicles with an electronic control module (ECM) also have a knock-sensor device. When the sensor detects knocking, the ECM retards the engine's ignition timing to eliminate the knocking. This happens so quickly that the driver never hears the knocking. But retarding timing decreases power and fuel economy. A higher-octane gasoline may improve the performance of knock sensor-equipped vehicles that have less power than when new.

Everyone here is free to go about their own Tex-Ex. I'm sticking to my plan. One tank of 87, two of 89. The computer will adjust by itself without needing to be reset. There are enough start-stop cycles in my standard weekly driving.

A few years a go, gas was around a buck a gallon, so the difference from $1.00 to $1.10 was a 10% increase in cost which would require a 10% increase in gas mileage to break even. Fast forward to today, the same difference from $2.00 to $2.10 is only 5% difference, so you now only need a 5% increase in fuel efficiency to pay for the difference.

The problem is, I still don't know if you actually get better mileage or not.
So, if I was getting 13.5 mpg before, now getting 15.5 makes the extra 5% I'm paying now worth it.:) Actually turns out to be a 14 % improvement in mpg.

For what its worth? I did this test a couple of years ago driving to Florida The end results were this:#1 we got better mileage using the 89 octane
#2 89 oct gave us more power, motor didnt ping
#3 but heres the thing when we calculated what it
cost per mile (difference in gas price) the 87 oct
was better (cheaper!) to run

They sell the 89 ethanol 10% here cheaper than the 87 regular. So I tried my own experiment. (Caseys General Markets $1.899 /gal yesterday)
with 2 tanks of gas so far the 89 ethanol 10% is getting about 2 mpg better and on the hills on US 71 in Arkansas and Missouri the engine does not downshift as quickly as it did with 87 so the rpm's stay lower. I drove 70 mph and got better gas mileage than when I was driving 65 with the 87 regular.

So I am sticking with the 89 ethanol 10%. The engine seems to run better too.

Many people here are making a huge error in their assumptions. First off, what we call gasoline is a very complex compound. There are hundreds, maybe thousands of different blends. What is ABC brand 87 octane in Los Angeles in January is quite a bit different than the same brand 87 octane in Chicago. In Chicago it the product will be different in different seasons. Different states have different formulations, etc.

Discounting all of that, we have to answer the following question: Does 93 octane gasoline have more energy per gallon than 87 octane? The quick and simple answer is NO. Actually 87 octane has more BTU's per gallon than the 93 octane.

As a side note I wrote an article a few years ago called "The Great Gasoline Rip-Off" that some may have read in industry rags. If you go back to about 1944 you would find that what we called gasoline at that time contained about 125,000 BTU's per gallon. Today we're down to about 104,640 BTU's per average gallon. What was gasoline in 1944 has very little in common with what we call gasoline today. We're subjected to more additives, oxygenates, and alcohol today. Most "gasoline" contains 10% ethanol, and ethanol only contains about 70,300 BTU's per gallon. So if you could run your car on 1944 gasoline you'd get about 25% better fuel mileage. Please note this paragraph is from memory so some numbers may be slightly off.

What is the octane rating? In very simple terms it's the ability of the fuel to resist detonation. The higher the octane rating the less volatile the fuel.

There are several ways to prevent detonation... you could lower the compression ratio, use higher octane fuel, or retard ignition timing are some examples.

Does the computer in your Ridgeline "know" what octane fuel you pumped into the tank? No.

How does the computer adjust for different fuels? It gets input from the knock sensor. A "knock" is early detonation of the fuel. When a knock is detected the computer retards the ignition timing. This is most likely to happen at full throttle, high load conditions.

So we're driving down the highway at 70MPH. Normal driving conditions... not pulling a trailer, unloaded, no huge hills to climb, etc. Will you get better fuel mileage with 87 octane or 103 octane? The answer is 87 octane every time.

Now if you intend to put the engine under heavy loads, run full throttle from stoplight to stoplight, etc. you will probably get slightly better fuel mileage out the 103 octane, but it would probably be hard to measure.

Unless you run your engine in a condition that the ignition timing would be retarded due to low octane fuel you can not get better mileage with higher octane fuel. The higher octane fuel would have to have more BTU's per gallon, but the opposite is true.

Oh well... out of time. Sorry that this message is not well organized... just wanted to put some old wives tales to rest.

-Joe

Does the computer in your Ridgeline "know" what octane fuel you pumped into the tank? No.

So we're driving down the highway at 70MPH. Normal driving conditions... not pulling a trailer, unloaded, no huge hills to climb, etc. Will you get better fuel mileage with 87 octane or 103 octane? The answer is 87 octane every time.

Unless you run your engine in a condition that the ignition timing would be retarded due to low octane fuel you can not get better mileage with higher octane fuel. The higher octane fuel would have to have more BTU's per gallon, but the opposite is true.

-Joe

CSIMO/Joe..... Thanks for taking the time give this information.... very interesting..... appreciate it!

Many people here are making a huge error in their assumptions. First off, what we call gasoline is a very complex compound. There are hundreds, maybe thousands of different blends. What is ABC brand 87 octane in Los Angeles in January is quite a bit different than the same brand 87 octane in Chicago. In Chicago it the product will be different in different seasons. Different states have different forumlations, etc.

Discounting all of that, we have to answer the following question: Does 93 octane gasoline have more energy per gallon than 87 octane? The quick and simple answer is NO. Actually 87 octane has more BTU's per gallon than the 93 octane.

As a side note I wrote an article a few years ago called "The Great Gasoline Rip-Off" that some may have read in industry rags. If you go back to about 1944 you would find that what we called gasoline at that time contained about 125,000 BTU's per gallon. Today we're down to about 104,640 BTU's per average gallon. What was gasoline in 1944 has very little in common with what we call gasoline today. We're subjected to more additives, oxygenators, and alcohol today. Most "gasoline" contains 10% ethanol, and ethanol only contains about 70,300 BTU's per gallon. So if you could run your car on 1944 gasoline you'd get about 25% better fuel mileage. Please note this paragraph is from memory so some numbers may be slightly off.

What is the octane rating? In very simple terms it's the ability of the fuel to resist detonation. The higher the octane rating the less volitile the fuel.

There are several ways to prevent detonation... you could lower the compression ratio, use higher octane fuel, or retard ignition timing are some examples.

Does the computer in your Ridgeline "know" what octane fuel you pumped into the tank? No.

How does the computer adjust for different fuels? It gets input from the knock sensor. A "knock" is early detonation of the fuel. When a knock is detected the computer retards the ignition timing. This is most likely to happen at full throttle, high load conditions.

So we're driving down the highway at 70MPH. Normal driving conditions... not pulling a trailer, unloaded, no huge hills to climb, etc. Will you get better fuel mileage with 87 octane or 103 octane? The answer is 87 octane every time.

Now if you intend to put the engine under heavy loads, run full throttle from stoplight to stoplight, etc. you will probably get slightly better fuel mileage out the 103 octane, but it would probably be hard to measure.

Unless you run your engine in a condition that the ignition timing would be retarded due to low octane fuel you can not get better mileage with higher octane fuel. The higher octane fuel would have to have more BTU's per gallon, but the opposite is true.

Oh well... out of time. Sorry that this message is not well organized... just wanted to put some old wives tales to rest.

-Joe
csimo, I am an avid fan of yours. I respect your knowledge and opinions. I would love nothing more than to have carte blanche acceptance of this post. But after all the unscientific research I have done, I cannot help but disagree with you. This judgement may be true because of your abrupt exit, or lack of supporting evidence. Regardless my opinions, I still differ to your knowledge, but also, stick to my guns. Thank you. My last question is when, why and how can we as people of this planet, overcome the grip of the oil entrepeneurs have over this world, and allow us to embrace scientific progress, to their coffers lose, and progress beyond dependence of dino oil? If it wasn't for the billions and gazillions of dollars lost in dino profits, we would not be talking this subject today. We would be praising the benefits of Hydrogen fuel cells and wondering why it took our fathers all this time to come up with this solution to a lifetime problem? Where is David when we needed him? I guess it's que sera, sera.

I agree with csimo for the most part. I've posted a few times why & how Premium gives more HP & torque in the middle and high end of the power band curve. It will also give you better mpg but there's going to be no noticeable difference at the low end of the curve such as crusing at 2200 rpm. Also, the increased mpg is going to be very small, perhaps 1 mpg. Testing for this on the road in uncontrolled conditions is almost impossible as trying to duplicate testing conditions would be very difficult. Everything has to be taken into account which can effect mpg: ambient air temp, air density, humidity, road temp, vehicle weight, tire pressure, wind, throttle position, rolling resistance from road surface and so forth.

csimo, vertrkr, that's all well and good. I understand your points and I understand the engineering behind them. Like I stated in BOLD LETTERS in my post, this is not about proving anyone wrong. It's about testing out a theory that was proposed here. No engineering required. Let's just let the test commence and see what happens.

One product that helps the fuel system a lot (and often increases mileage as a result is Fuel Power 60 which can be found at Lubecontrol.com. It is the eqivelent for fuel that their LC20 is for oil. These products are highly regarded by lubrication geeks (see bobistheoilguy.com) and have been time tested for many years. And they do not cost that much, about $30 per gallon and you use 1oz. of FP60 per 5 gallons of gas. They do not say it will result in better fuel economy but since using FP60 I get two miles per gallon better mileage and I know the fuel system is being cleaned and lubricated properly and the gas is conditioned to a better degree.

I agree with csimo for the most part. I've posted a few times why & how Premium gives more HP & torque in the middle and high end of the power band curve. It will also give you better mpg but there's going to be no noticeable difference at the low end of the curve such as crusing at 2200 rpm. Also, the increased mpg is going to be very small, perhaps 1 mpg. Testing for this on the road in uncontrolled conditions is almost impossible as trying to duplicate testing conditions would be very difficult. Everything has to be taken into account which can effect mpg: ambient air temp, air density, humidity, road temp, vehicle weight, tire pressure, wind, throttle position, rolling resistance from road surface and so forth.
When I first posted my "impressions" and "experiences" of a perceived enhanced performance of my Ridgeline, burning 89 octane fuel, I merely wished to pass those on to my fellow ROCers. Like shovlhd, I am not trying to prove whether or not previous researched data wrong. However, I was caught by surprise by how my Ridgeline engine seemed smoother, better pick-up on acceleration both at low and high speeds! Furthermore, I got more miles from a tank of gas! (310 to 400 miles versus 270 to 290 miles on a 20 gal fill). This, while traveling the same boring route day in and day out and the one long trip to Cleveland. Granted, the increased mpg is nothing to celebrate or make headlines. When I did the convertion first of this month, I had over 8000 miles and seven months of driving behind me, burning 87 octane. So I knew how my truck was driving. And it's not just me who got this impressions. I asked my wife to switch fuel for her '02 CRV. After a couple of tanks, she reported the same impressions. Still following up on her mileage. As I mentioned already, after this tank of 89, I'm switching back to 87 for a few fills. If I see no difference I will say so here, and apologise for raising hackles for my BS. On the same token, if I perceive a difference, I will go back to 89 and stay with it. I will post my findings for whomever may care to know.:) I do respect Vertrker's and Csimo's knowledge and opinions, and continue to do so. I've read all their posts on this forum, and I realize their expertise in their fields.:)

My last question is when, why and how can we as people of this planet, overcome the grip of the oil entrepeneurs have over this world, and allow us to embrace scientific progress, to their coffers lose, and progress beyond dependence of dino oil? If it wasn't for the billions and gazillions of dollars lost in dino profits, we would not be talking this subject today. We would be praising the benefits of Hydrogen fuel cells and wondering why it took our fathers all this time to come up with this solution to a lifetime problem? Where is David when we needed him? I guess it's que sera, sera.

How do we solve the problem? There are many ways, but the fact is that the deck is stacked against the consumer.

Some here are old enough to remember the Arab Oil Embargo in 1973 - 74. For those that were too young, or weren't around I'll recap what happened.

In 1973 the US was in a period of high inflation. Items on grocery store shelves were going up every day. Oil was following suit. In March, 1973 Nixon placed price controls on crude oil. A few months later Egypt attacked Israel. That became known as the Six Day War. Israel did major damage to attacking forces and this disclosed to OPEC just how much support the US had been giving to Israel. They didn't like the results of the war and that they were beaten very badly with US made equipment.

All this made OPEC mad and they decided to hit the US where it hurts... cut off our oil supply. The price of gasoline went from $0.30 per gallon and jumped to over $1.00 per gallon at the height of the crisis.

There were long lines at the gas pumps. You had to wait in lines blocks long if the station actually had any gasoline. Many, many stations just put up signs that proclaimed "NO GAS" and went home.

To try and shorten the gas lines a nationwide gas rationing system went into effect. For the first time since WWII we had gas rationing. In most places you could buy gasoline based on the last number of your license plate. If your plate ended in an odd number you could buy gasoline on Monday, Wednesday, or Friday. If even number plate you could buy on Tuesday, Thursday, or Saturday. Stations were closed on Sunday by Executive Order.

There were other "nice" things that happened during that period. We were told to turn our home thermostats back to 68 degrees in the winter. Daylight Savings Time was implemented year round. Wage and price controls were implemented.

Since that time we've gone thru at least one other major gasoline shortage, but I won't go into that one now.

So what did we learn from the Arab Oil Embargo? Apparently little or nothing. Our dependency on foreign oil is greater today than ever. The recent energy bill has very little money in it to reduce our foreign oil dependence.

To be perfectly blunt on the issue... it doesn't matter if you're a Republican or Democrat, there is very little incentive in being a politician that takes a real stance against the oil establishment. This is not a Democrat / Republican issue... neither are working for the interest of the consumer on this issue. Enough politics... I do not want to get into a political discussion, but on this issue there are decades of evidence to prove my point.

Are hybrids the answer? Not in my opinion. I don't see how hybrids make sense in the long term. I suppose they are good enough for those who want to appear to be politically correct. Perhaps storage battery technology will improve in the future and I'll change my mind, but for now I think we're creating a huge problem when all these batteries start going bad.

Are hydrogen fuel cells the answer? Maybe in the long run, but I really don't know. I will be first to admit that I am weak in knowledge in this area. I know there are still significant issues to overcome, and I hope this technology works out.

How about diesel? Well the rest of the world discovered the benefits of diesel decades ago. Due to some really terrible moves by GM here in the US we've got a bad taste for diesel. I really love diesel technology. It's not a long term answer, but it could sure bridge the gap while we wait for a viable long term solution. In a way it could be a long term answer if you consider biodiesel... we could grow enough fuel to significantly reduce the need for crude oil. Do yourself a favor and go drive a VW Jetta TDI. You will be amazed at how well a modern diesel engine works. They are not the slow, stinky vehicles that most people believe them to be. I've owned three Jetta TDI's and regularly got over 50MPG. Diesel fuel contains much more energy per gallon than gasoline. I wish there were many more diesel engine options in the US. Go to Europe and you'd find diesel vehicles are preferred.

Nuclear (actually steam)? When I first got into the automotive business in the mid-70's I firmly believed that by the year 2000 we would be driving cars powered by small nuclear reactors. You would only buy the reactor once and transfer it from vehicle to vehicle as you wore them out, etc. If it hadn't been for Three Mile Island and Chernobyl I believe this would have happened. I still believe the technology is both safe and possible, but there are very few interested in developing the technology and few consumers would accept it. Steam power is an amazing product. Probably one of the cleanest, most powerful and efficient technologies known to man. A nuclear reactor is just a way to make steam, and steam is the answer to a lot of problems.

Back to reality. Big oil has bought and paid for our politics. These are no longer US companies... many big oil companies are not based in the US and are multinational conglomerates that are not interested in anything other than perpetuating and growing world demand for oil.

I'll end on a semi-political note for you to consider. I recently heard a definition of insanity that I liked. The quote was, "the definition of insanity is to keep doing the same thing over and over again, but expecting different results". So to apply this to politics... anyone that keeps voting for Republicans and Democrats and expects anything different than what we've been getting from Democrats and Republicans is insane. What's the alternative? Sure wish I knew.

I apologize if I offended anyone with my semi-political remarks. I really don't want this to be a political discussion, but I did want to point out that I don't believe the politicians are interested in solving this issue. It's been over 30 years since the Arab Oil Embargo... they've had plenty of time. Don't pay attention to what they say, pay attention to what they do.

-Joe

I apologize if I offended anyone with my semi-political remarks. I really don't want this to be a political discussion, but I did want to point out that I don't believe the politicians are interested in solving this issue. It's been over 30 years since the Arab Oil Embargo... they've had plenty of time. Don't pay attention to what they say, pay attention to what they do.
No offense taken here because it's difficult, if not impossible, to separate oil and politics. That's the problem. Great post, Joe! It brought back memories of good and bad times.

And I will just merrily go my way using 87 octane unless I decide to tow something. While the engine may sound or feel a little difference, unless it improves the life of the engine or the mileage I am getting, I don't really see it as necessary. But to each their own.

Some here are old enough to remember the Arab Oil Embargo in 1973 - 74. For those that were too young, or weren't around I'll recap what happened.


-Joe
Joe, thanks for the recap I was in the US Air Force in that time, stationed at Beale AFB, CA with the SR-71. Just reassigned back from the Philippines/Vietnam.
At that age, I was young enough only to care for my family, do my duties, and live day by day. Not really aware of the conditions causing the gas rationing, but remember those lines and gasless days. Living on base, I could leave the car in the driveway and took the Air Force bus shuttle, organized for the base because of the embargo. So I am grateful for your recap, which made me recall those days and now understand them better. Thanks.:)

Once again, great post Joe! Well done and thank you! Anybody have H. Ross Perot's phone number? Seems that he had some pretty strong opinions not too long ago about the subject. Was he right?
Gee, that's twice in 24 hours that I brought up his name in reference to news or posts on the ROC. It's just a coincidence, really... I think.... but maybe........ Phew! I really don't want to go spinning off on that tangent.... but.......... :confused:

Tex, keep up the good work on your experiment. I am sure that your observations and the results will be very interesting even if they do cause a lot of scientific arguments to try to prove the results one way or the other. For what it's worth, I always use 89 because I believe that I can feel a difference in how smooth the engine runs. It's sort of like the way the car or truck feels like it drives better when it is nice and clean and shiny as compared to dirty. It is probably just me and my imagination or lower air resistance, it doesn't matter to me. I like it that way so I keep them clean, run 89, and keep the tires a pound or two on the hard side of normal. I have never done a comparison with 87 or have any reason to believe that I do or do not get better mileage using 89. On the very rare occasions that I have tried premium, I don't notice enough of a difference to justify that additional cost for every day driving.

Tex,

I'm looking forward to the results of your experiment. I've considered trying the experiment myself, but my driving hasn't been normal the last couple of tanks and I really paid on the last tank (15.9), the lowest since the 1st two tanks back in April/May. Of course, that was hot-rodding it and hauling a heavy load on the same tank, so it would be expected to be lower.

Another potential problem I see with this type of experiment is that this time of the year, the temperature varies greatly from morning to night (and day to day), so your air pressure in the tires will vary quite a bit. I wonder if this would have as much (or more) impact than the octane? Taking averages over time will rule this out though.

Tex,

I'm looking forward to the results of your experiment. I've considered trying the experiment myself, but my driving hasn't been normal the last couple of tanks and I really paid on the last tank (15.9), the lowest since the 1st two tanks back in April/May. Of course, that was hot-rodding it and hauling a heavy load on the same tank, so it would be expected to be lower.

Another potential problem I see with this type of experiment is that this time of the year, the temperature varies greatly from morning to night (and day to day), so your air pressure in the tires will vary quite a bit. I wonder if this would have as much (or more) impact than the octane? Taking averages over time will rule this out though.
Good point. I've already taken that under consideration. I will monitor it daily, and attempt to keep it where it is now, 32 psi, cold pressure.

Joe, thanks for the recap I was in the US Air Force in that time, stationed at Beale AFB, CA with the SR-71. Just reassigned back from the Philippines/Vietnam.

That must have been fun, working on a plane that leaked jet fuel all over the tarmac while there was a gas shortage going on (I know, not the same stuff, but the principle behind it...)

That must have been fun, working on a plane that leaked jet fuel all over the tarmac while there was a gas shortage going on (I know, not the same stuff, but the principle behind it...)
Leaked!!! How about pouring!! Crews had to squeegee it out after taxing! Did you work with them?

[QUOTE=csimo]
In March, 1973 Nixon placed price controls on crude oil. A few months later Egypt attacked Israel. That became known as the Six Day War.

Just a point of history. The "Six Days War" was in June, 1967.;)

[quote=csimo]
In March, 1973 Nixon placed price controls on crude oil. A few months later Egypt attacked Israel. That became known as the Six Day War.

Just a point of history. The "Six Days War" was in June, 1967.;)

You are correct! Don't know what I was thinking at the time... tired I guess. The 1973 action was the Yom Kippur (sp?) Conflict. I think it's also known as the Two O'Clock War.

Thanks for the hand slap. I need it sometimes!

-Joe

http://www.superchargersonline.com/content.asp?ID=105

octane doesn't increase hp, or fuel economy. the only time u need to use a high octane is if you car knocks and thats the only time. i have includes a link.

http://www.superchargersonline.com/content.asp?ID=105

octane doesn't increase hp, or fuel economy. the only time u need to use a high octane is if you car knocks and thats the only time. i have includes a link.
From that article: "On modern engines with knock sensors, higher octane fuel may make the engine run better if the knock sensors are retarding the ignition timing, which hinders performance. High octane fuel does not burn cleaner, it does not clean your engine, it does not increase horsepower or torque (unless you are experiencing knock), it does not smell better, it does not increase fuel economy (unless you are experiencing knock) and is not better for the environment. "

So, how do you know if your engine is retarding timing to prevent knock?

So, how do you know if your engine is retarding timing to prevent knock?

The only real way to find out if your computer is retarding the ignition timing would be to use an ODBII scan tool that can read the timing values. A Davis CarChip, or ScanGauge can do this. There may be cheaper alternatives.

A couple of years ago a guy called "mogur" ran a test on his MDX using a CarChip. Keep in mind that the MDX engine is very similar to the Ridgeline engine... one major exception is that Premium fuel is recommended for the MDX, but not for the Ridgeline. This would indicate to me that the initial ignition timing maps for the MDX are slightly more aggressive.

Here's what he posted:

"Definitive gas octane requirements study results.
I have aquired one of the Davis CarChips and ran it in my MDX for over a month through 4 tanks of gas, two regular and two premium. I was able to monitor the spark advance using the CarChip (which is the true measure of whether or not higher octane is of any value in a given OBDII engine with detonation sensors). The result? Except at full throttle or very near to it, the spark advance was the same with both Premium and Regular. This indicates that Premium was doing absolutely no good and was not improving performance and that, conversely, Regular was not hindering it. If you were towing a heavy load and spending a lot of time near or at WOT, then it appears that there is a slight improvement in performance with Premium (the spark advance was about 2 to 3 degrees greater) but otherwise, it is buying you nothing and costing you money.

Tom

Update: I have since also run a few tanks of midgrade (89 octane)
through under the same conditions and noted the spark advance results. With midgrade, the spark advance was identical to Premium (91 octane). This tells me that under even the most heavily loaded WOT conditions, there is no advantage to premium over mid-grade under any circumstances. Note: In all cases I used the same brand of gasoline (Shell with Ethanol) from the same station. The altitude of this test was approximately 800 feet, the vehicle had 23,000 miles on it, the average temperature was approximately 80 degrees, the average humidity was approximately 25 percent, and I am in the Los Angeles area. Also, this is applicable to a 2001 and 2002 MDX and the results may be different for the 2003 260hp engine."

-Joe

csimo, great information. Thanks. If this thread does not accomplish anything, it is bringing back a lot of proven tests already out there, that I and a lot of other folks can learn from. Thanks again joe.:)

Now we need someone with the wherewithall to do this type of MDX test on our Ridgeline engine and this topic will have some true scientific evidence to fall back on when comparing to our impressions of performance and somewhat scientific mileage comparisons. This MDX tester seems to have tried to simulate as much environmental controls as can be expected outside of a laboratory and his results are explained in easy to understand terms. Thanks for bringing this test example to our discussions.

Thanks CSIMO.

The only real way to find out if your computer is retarding the ignition timing would be to use an ODBII scan tool that can read the timing values. A Davis CarChip, or ScanGauge can do this. There may be cheaper alternatives.

A couple of years ago a guy called "mogur" ran a test on his MDX using a CarChip. Keep in mind that the MDX engine is very similar to the Ridgeline engine... one major exception is that Premium fuel is recommended for the MDX, but not for the Ridgeline. This would indicate to me that the initial ignition timing maps for the MDX are slightly more aggressive.

Here's what he posted:

"Definitive gas octane requirements study results.
I have aquired one of the Davis CarChips and ran it in my MDX for over a month through 4 tanks of gas, two regular and two premium. I was able to monitor the spark advance using the CarChip (which is the true measure of whether or not higher octane is of any value in a given OBDII engine with detonation sensors). The result? Except at full throttle or very near to it, the spark advance was the same with both Premium and Regular. This indicates that Premium was doing absolutely no good and was not improving performance and that, conversely, Regular was not hindering it. If you were towing a heavy load and spending a lot of time near or at WOT, then it appears that there is a slight improvement in performance with Premium (the spark advance was about 2 to 3 degrees greater) but otherwise, it is buying you nothing and costing you money.

Tom

Update: I have since also run a few tanks of midgrade (89 octane)
through under the same conditions and noted the spark advance results. With midgrade, the spark advance was identical to Premium (91 octane). This tells me that under even the most heavily loaded WOT conditions, there is no advantage to premium over mid-grade under any circumstances. Note: In all cases I used the same brand of gasoline (Shell with Ethanol) from the same station. The altitude of this test was approximately 800 feet, the vehicle had 23,000 miles on it, the average temperature was approximately 80 degrees, the average humidity was approximately 25 percent, and I am in the Los Angeles area. Also, this is applicable to a 2001 and 2002 MDX and the results may be different for the 2003 260hp engine."

-Joe

This why I have stated the computer needs to be reset or your gasoline grade testing will not mean very much. Once the computer has adjusted its maps for 87 octane there is no reason for it to change when greater octane fuel is used. It has no way to sniff out the gas that the tank is filled with.

What do you mean by a computer reset. :confused: I thought we were dealing with a computer that was resetting itself based upon ignition detection (Knock sensor). Do you mean it needs to train itself over time?

If you were towing a heavy load and spending a lot of time near or at WOT, then it appears that there is a slight improvement in performance with Premium (the spark advance was about 2 to 3 degrees greater) but otherwise, it is buying you nothing and costing you money.

Which is why Honda recommends using premium when towing loads in excess of 3,500 lb.

Starting 3rd tank with 89 Oct. 2nd tank 19.28 mpg. I was avg. 18.5 mpg with
87 Oct and the smoth driving tech,'s. I pay 8 cents more for 89 at $2.13; therefore, a approx 4 % more in price so 18.5 x1.04 = 19.25 mpg. So it a wash so far. I'm on my 3rd tank of 89 and will use a forth and decide which to use.:rolleyes: