[JamieO]

I see many advise using high octane fuel for towing. I am thinking seriously about buying a RL and wanted to get some input on my situation. If I buy one, it would be my daily driver around town all week. Then, on the weekends, I would be towing a 3000# (loaded) 6x12 cargo trailer. I typically top off the tank before leaving, then fill again when I return home.

So, would it help to top off with 93 on Fridays? Or, should I just run 89 all the time? Given that I tow pretty much every weekend, it would be hard to run 87 all week, then 93 every time I tow, so I'm trying to find the right balance.

FWIW, I did a test-tow for 20-30 minutes using 87 and it handled my trailer quite well, but I was on back roads and never went over 60.

 

[beatle]

From what I understand, the difference in power from higher octane is not all that incredible. I'd just fill up with 93 before you head out, and then top off with 87 when you get home. That will get you at least some benefit when you need it.

 

[speedlever]

Per my 2008 OM, don't worry about using premium until/unless you are towing 3500 lbs or more:

Does your OM provide the same info?

 

[MrNewEngland]

I tow with my RL on a semi-regular basis. Enough to justify always running 89 in it. I usually am towing fairly light trailers but there have been a few times when I was approaching 5,000# and the RL handled it well (with the 89 octane running through it).

Just my $0.02.

 

[rollinhonda]

Can't say I've noticed anything appreciable jumping above 89 octane. That always seems to be the sweet spot. If I was doing some major towing I would likely go with 91 as more of a 'it can't hurt' to do it because I have no idea if it really helps or not.

 

[Swolstencroft2396]

OK I've actually done some extensive online research for this myself everything that is said about more power and extra mpg and everything the octane rating of fuel stands for the amount of fuel that can be compressed in each revolution meaning that the higher octane you go the more volatile the gasoline is and going to a higher octane than 87, which I believe is the factory specified octane rating, can actually lead to premature detonation of the fuel which can cause engine damage so to sum it up it's a waste of money and over time could cause significant engine damage. Hope this helped!

 

[AWILLIAMS64]

ok for my 2 cents worth. I bought a 19 foot travel trailer last year. It weighs about 3200 lbs loaded and I tow about 10 weekends per year with it. An average of about 2-300 miles each way when I go. I have ran different brand of gas, different octanes, etc. I have noticed very little difference in mileage and performance with anything. I only get 8-10 mpg while towing, the travel trailer is a big wind sail. I have kept track and used different octanes from the same brand on different trips to the same destination with maybe a tenth of a mile per gallon difference. To me, that is not worth it.

 

[beatle]

...the octane rating of fuel stands for the amount of fuel that can be compressed in each revolution meaning that the higher octane you go the more volatile the gasoline is and going to a higher octane than 87, which I believe is the factory specified octane rating, can actually lead to premature detonation of the fuel which can cause engine damage...

It's actually the opposite. The higher the octane, the slower the burn, and the more resistance you have against pre-ignition. This resistance allows the engine to fire the spark later in the cycle and make more power. When running a lower octane in the RL, the engine will fire a bit earlier so as to avoid pre-ignition. This comes with the tradeoff of slightly less power.

 

[speedlever]

... and of course the ECU can adjust within a limited range to accommodate changes in fuel octane as well.

 

[SpeedPunk]

It's actually the opposite. The higher the octane, the slower the burn, and the more resistance you have against pre-ignition. This resistance allows the engine to fire the spark later in the cycle and make more power. When running a lower octane in the RL, the engine will fire a bit earlier so as to avoid pre-ignition. This comes with the tradeoff of slightly less power.

What he said...

 

[jonesbb630]

OK I've actually done some extensive online research for this myself everything that is said about more power and extra mpg and everything the octane rating of fuel stands for the amount of fuel that can be compressed in each revolution meaning that the higher octane you go the more volatile the gasoline is and going to a higher octane than 87, which I believe is the factory specified octane rating, can actually lead to premature detonation of the fuel which can cause engine damage so to sum it up it's a waste of money and over time could cause significant engine damage. Hope this helped!

May I suggest you don't believe everything you read online. Yes this is online as well, but I can assure you that you've been misinformed. The designer of the Ridgeline said it will run on 87 but run better on 89+ octane.

 

[csimo]

The use of premium fuel will result in about a 10 horsepower increase. You cannot damage the engine by towing with regular fuel.

 

[Swolstencroft2396]

I actually did not know that myself and yes I do realize it was online research that I did so I definitely could be wrong haha but I do have 204,000 miles on my Ridgeline and have never used anything more than 87 towing our 4,000 pound boat with a brakeless trailer long distance, in excess of 500 miles, and up and down steep unpaved roads so even though it is highly likely I am wrong about the fuel thing I really don't believe it needs more than 87 octane to run effectively for most to all situations of towing

 

[MrNewEngland]

I actually did not know that myself and yes I do realize it was online research that I did so I definitely could be wrong haha but I do have 204,000 miles on my Ridgeline and have never used anything more than 87 towing our 4,000 pound boat with a brakeless trailer long distance, in excess of 500 miles, and up and down steep unpaved roads so even though it is highly likely I am wrong about the fuel thing I really don't believe it needs more than 87 octane to run effectively for most to all situations of towing

I'm less worried about your octane use than I am your use of run-on sentences.

 

[Ian Brantford]

Note that results may vary with the engines before or after the 2009 refresh. With the 2009 model year, we got an engine and transmission that were tweaked to give better torque in the mid range.

I have the 2009, and have gone back and forth several times between octane 87 and 89. I also used to routinely use premium 91.

I can say that 89 pays for itself over 87 in unloaded mixed driving and when towing heavy (5000 lb boat/trailer). Actually, the more the load, the more that higher octane pays for itself. The difference between 9 and 11 MPG doesn't seem like a lot, but it's about 20% better! In normal mixed driving, I get about 8-9% better fuel efficiency with 89 (exactly the price difference), and it appears to be a bit better than that in winter, say 12%.

My butt dyno tells me that 89+ helps when towing heavy. So does the transmission, which shifts much less at highway speed. I have not quantified either result.

I have never done any reproducible testing to confirm whether going above 89 is worthwhile, towing heavy or not.

Special case: I used 91 most of the time during my first year of ownership and could not see a difference from 87. However, I can consistently reproduce a difference with anything above 87 in the years since. Possibly engine break-in was a factor.

Summary: use 89 all the time. It pays for itself most of the time, and you'll always be ready to tow.

 

[speedlever]

Price varies so much on fuel grades, that may be a wash. I can see price differences of 20-30 cents/gallon going from 87 to 89 octane in my area. I've tried 87 and 93 octane (and 89) and have never noticed any performance difference (power or mpg) in my normal driving environment.

This truly seems to be an individual experience as to whether there is any benefit to using a higher octane fuel.

That being said, I once did a 7 month test of non Egas (87 octane) and found a consistent 1.5 mpg increase (estimated). But without being in a controlled testing environment, there are simply too many variables to draw any definitive conclusions.

 

[Dnick]

Price varies so much on fuel grades, that may be a wash. I can see price differences of 20-30 cents/gallon going from 87 to 89 octane in my area. I've tried 87 and 93 octane (and 89) and have never noticed any performance difference (power or mpg) in my normal driving environment.

This truly seems to be an individual experience as to whether there is any benefit to using a higher octane fuel.

That being said, I once did a 7 month test of non Egas (87 octane) and found a consistent 1.5 mpg increase (estimated). But without being in a controlled testing environment, there are simply too many variables to draw any definitive conclusions.

Exactly......... depends on your case as far as economies go. We only pay 10 cents more between the grades (87, 89, 91) in California. Sometimes slightly more or less.

You WILL get more HP from your engine (with premium octane) if you demand it (throttle, load) with higher Octane, but you never really "need" it. Engine just adjusts to your fuel & performs accordingly. No different than having an engine with 10 less (or more) HP. They both work just fine.

Don't forget there is a ceiling above which the higher octane exceeds the RLs ability to adjust for it to generate benefit (engine variable timing limitations). I'm not certain, but I believe anything above 91 octane is wasted effort (actually can imperceptibly reduce performance, given timing is not adjusting to match octane, and very slightly less heat energy in that higher octane.... ). Anyone remember what that threshold number is (91 or ???).

 

[speedlever]

That HP gain is at higher rpms too... but there are beneficial gains lower... per Gary Flint... which can result in less shifting. Still...

In my area we have 3 grades: 87, 89, and 93. So regardless whether there is a top limit the ECU can accommodate, 93 is still premium in my area.

 

[jonesbb630]

Will the 87 octane damage when towing? No.

However, the truck will run better, and give you better fuel mileage. This is not research, it's from personal experience. In my area, 91+ octane is the only fuel available without ethanol. From experience, I have had bad experience from ethanol built-up in injectors from another of my vehicles. So for me, from experience, the extra $ at the pumps for 91+ octane pays for itself. It also gives me the peace of mind that I don't burn ethanol.

J

 

[IanRTL]

I've said this in many threads before, but my truck never liked 87 octane for some reason. It's not that it ran badly, but it was much more smooth with 89+. I also saw a slight increase in fuel mileage (1mpg or so in normal driving) and the truck just simply felt better when driving. I always used 89 until I took a long trip with my wife. On the way down, I had a tank full of 89. The truck ran just fine on the highway up and down some steep grades. It hit 3rd gear and 4000 RPM several times maintaining 75mph. When I had to fill up, the only options were 87 and 93, so I choose 93. Within a few miles, I noticed a little better feel and much less upshifting to maintain speed. We reached our destination, stayed for a few days and started our drive back. I filled up at the same station again to do a bit of an unscientific test. The temperature and weather conditions were the same. The rest of the way home with 93, the truck never got close to 4000 RPM as it seemed to have a slight bump in power and I ended the trip with a 0.5mpg increase. Since I now only drive about 4-5k miles a year and fill up around once every four weeks, I use 93 all the time.

That being said, I would use 89 religiously if I were you. See how it pulls with it. Then try 3-4 tanks of 93. If it shows any increase in feel or pulling power, then you can make your decision on what you should do from there. The $0.10 increase in price for 89 is a no-brainer. The sometimes $0.30 increase for 93 may not be worth it to you. For me, it's about an extra $50 a year to run 93 octane over 89. Negligible, at best, for the quiet, smooth, strong driving experience it provides for me.