Are those of you who are getting less than desireable gas mileage running your fan in AUTO mode on your RL's? I am usually a 2/55 guy in that I roll down the windows or crack the sunroof and open my back window which yields excellent ventilation.

Well, I took the wife on a road trip over the weekend and she is not a 2/55 gal and likes the A/C running so instead of showing her how all the controls worked. I just explained how AUTO works. Talk about a gas mileage drop. What really surprized me is that the A/C compressor pretty much ran all of the time no matter what the outside temperature was. The A/C compressor even ran after dark when it was really not that hot outside. The A/C compressor only kicked off after I turned the dial to over 75 degrees F.

Not only did my highway mileage drop but the city gas mileage was substantially lower.

If you are getting bad gas mileage, use the fan in manual mode or roll down the window because AUTO mode may be your problem.

I would like to add that with the fan in manual mode, the A/C compressor still comes on until you hit the A/C button to turn it off if the temperature is set too low on the display. If the display doesn't say A/C and then off, it ain't off.

A/C is better left controlled in the AUTO mode as it will decide when the compressor needs to run or not, that is one of the purposes of AUTO. Gas mileage will suffer when using A/C, but the driver will not.

At a cost of 1 or 2 mpg, I choose comfort.

When I want A/C, I use the auto setting, but almost always set the temp above 75 -- in my truck, anyway, 75 feels more like 65 to me. It's cold! I find that turning on auto, and setting it at 79, keeps me nice and cool, without putting too much strain on the truck, and my gas mileage doesn't seem to suffer much at all.

At a cost of 1 or 2 mpg, I choose comfort.

My thoughts exactly.......

Yet I heard that windows open put enough of a drag on your vehicle at highway speeds that open windows often nullify any mileage savings. It's often more fuel efficient to use A/C as opposed to windows...

But I just love the wind tunnel tested hairdo I can get from dropping all the glass and enjoying that fresh air whipping through my Ridgeline...:cool:

Auto A/C set at 67 deg F costs me less than 1 mpg vs no A/C.

This is less than 20 fewer miles per tank.

Decrease may increase as summer heats up.

Well, it is interesting what you guys are telling me because I lost about 2.5 mpg on the highway running the system in AUTO.

I went from 23.5 mpg to about 21 mpg in pure highway driving. In the city I went down about 5 mpg from 17 to 13 which is about a 24% loss in gas mileage. That is way too much IMHO. I guess it's time to take a trip to the dealership.

Yet I heard that windows open put enough of a drag on your vehicle at highway speeds that open windows often nullify any mileage savings. It's often more fuel efficient to use A/C as opposed to windows...

But I just love the wind tunnel tested hairdo I can get from dropping all the glass and enjoying that fresh air whipping through my Ridgeline...:cool:

I have heard that is true as well but I usually only open the sunroof and the back window, not the sides. I tend to believe that this is less of an issue on the RL as it is not as much a flying brick as some other trucks.

Mythbusters did a show on using AC vs. driving with windows down.
The AC might drag the engine down, but the windows drag the vehical. Does anyone recall their findings?

Mythbusters did a show on using AC vs. driving with windows down.
The AC might drag the engine down, but the windows drag the vehical. Does anyone recall their findings?

Windows down vs. air conditioning
"Urban puzzle": it is more efficient, on a hot day, to run with the A/C on and windows up than to run with windows down (b/c of increasing car's drag).

Computer-based mpg measurements:

11.7/11.8 with A/C on and windows up
11.7/11.8 with A/C off and windows up
11.3 with A/C off and windows down
So, according to the computer, it's better to use A/C with windows up.

This was too quick and easy for TV, so they decided to stage a seven hour marathon, race-til-you're-empty duel, with Jamie driving an SUV with A/C on and Adam driving an SUV with windows down. Though, once the safety inspector intervened, it was no longer a seven-hour marathon, it was a bit slower (45mph instead of 55mph), and a lot shorter (only 5 gallons each).

Jamie's A/C car ran out of gas first -- Adam's windows down SUV ran for another 30 laps -- completely contradicting the computer mpg estimate. Computer estimate based on air flow into the engine, so it would appear that it is unable to properly model the difference between A/C and windows down.

Mythbusted

And obviously drag causes more of a penalty at higher speeds. There is virtually no loss due to drage in stop and go traffic.


As far as the original topic goes I too was surprised that the AC was on all the time until I figured out how to turn it off. It kicked my initial MPG in the butt as well.

Now I use it only when necessary, but I assume it will be more necessary as summer gets into swing.

I'm getting 19 mpg city driving with the windows down and the AC set on 68.:DUphill both directions in waist-deep snow? ;)

I'm getting 19 mpg city driving with the windows down and the AC set on 68.:D

You must get about 40 mpg on the highway dragging a parachute behind your RL as well.

If you are interested in efficency then do this. When the Ridge is hot inside , roll down the windows until you get most of the heat out. Second, turn the A/C to AUTO and use the RECIRCULATE mode. The compressor then has a lower discharge pressure due to the cooler air being flowed across the evaorator. Lower discharge pressure equals less horsepower required to drive the compressor. not a major difference in MPG , but, a major major factor in life of the compressor!!!! Yes, I work on A/C systems..............;)

im not sure what your trying to say...i have the RT so what do i do turn on the ac and do what and what? sorry :confused:

OK sorry it was 18.7mpg., 345miles, 18.36gal. you do the math. Still had about quarter tank left to. AC stays on 68 drivers side 75 passenger side. Yes windows down. Hwy. I'm getting 23 - 25 windows up. Do you want my build date and color, maybe thats your problem. Never tried the parachute thing enlighten us on how and why you would be doing this. Maybe thats why your mileage is low. :rolleyes: Take some bling off the truck, it'll get better mileage.

I have never heard of anyone driving with the A/C on and the windows down except maybe when puffing on a Marlboro. No offense or anything but that just doesn't make sense to me. I got the impression as I think LATEOTT did that you were joking. That's why I added the joke about the parachute.

I don't think that I could get 18.7 mpg in the city if every block were 3 miles long and went thru 50% of the stoplights on green with my A/C on and the windows down. I do have some open spaces around here but we also have our share of real city blocks and very heavy traffic in the cities. By my signature, you can see that I live in Ohio where our state tree is the orange construction barrel which means no one is going anywhere fast in the city or the highway in certain areas.

It would be helpful if you posted the driving conditions while you achieved this type of mileage such as terrain, congestion, city block length, whether you are driving 28 mph in a 35 mph zone blocking traffic, etc. Did you drive the entire 345 miles with the windows down in the city? Were you ever on the freeway during this 345 miles?

It would also help if you posted your general geographic location. I see that your screen name is Northernlights. Do you live in Northern Canada where it is 68 degrees anyways so your A/C compressor isn't even running with the knob set at 68? It's been hot here in Ohio lately with daytime temps in my area reaching 85 degrees consistently so we use our A/C.

Some of us have a different perception of what city driving is. What I call city driving in Cincinnati is vastly different than what someone in Winchester Kentucky would encounter. (No offense to anyone who lives in Winchester) I'm not trying to call B/S on your claim, I'm just trying to comprehend it.

As for my "bling", I don't see it causing any major aerodynamic drag on my vehicle. In fact, I believe my tonneau helps my mileage on the highway. Only slightly but it does help. Are you maybe implying that you don't like my bling? If you don't thats ok. I'm not trying to make you happy, just me and if you don't like it, that's your problem. You might try a little bling yourself. It builds character.

Let me crow abit.My ridge now has 2500 miles and I got 19.2 on my last tank with some highway travel.This is with AC on auto and sometimes windows down.

Air on and windows down is the most comfy ride.

Air on and windows down is the most comfy ride.

I also like the Air on with front windows down. I hope its not messing up the compressor.

I run a/c on all the time...not auto....i just got 15.1 mpg on the last tank. I do only have 452 miles right now. I take it that it will get better as the engine breaks in? (this was 80% hwy)

I also like the Air on with front windows down. I hope its not messing up the compressor.

No, but there is a poster of you on some sheik's wall next to the one he has of Britney Spears and both are held in same high esteem.:D

Windows down vs. air conditioning
"Urban puzzle": it is more efficient, on a hot day, to run with the A/C on and windows up than to run with windows down (b/c of increasing car's drag).

Computer-based mpg measurements:

11.7/11.8 with A/C on and windows up
11.7/11.8 with A/C off and windows up
11.3 with A/C off and windows down
So, according to the computer, it's better to use A/C with windows up.

This was too quick and easy for TV, so they decided to stage a seven hour marathon, race-til-you're-empty duel, with Jamie driving an SUV with A/C on and Adam driving an SUV with windows down. Though, once the safety inspector intervened, it was no longer a seven-hour marathon, it was a bit slower (45mph instead of 55mph), and a lot shorter (only 5 gallons each).

Jamie's A/C car ran out of gas first -- Adam's windows down SUV ran for another 30 laps -- completely contradicting the computer mpg estimate. Computer estimate based on air flow into the engine, so it would appear that it is unable to properly model the difference between A/C and windows down.

Mythbusted
That show was on tonight (6/21)... hahaha

And I am honest, I can say I only get 13-16 city and 14-18 with the winter crap gas. We'll all be suffering when they change the fuel to 15% ethanol year round. It's coming.

Ahhh. What are you running this time of year in your area ethanol blend wise? This may be the key to the difference in what gas mileage we are getting. In this part of the country we have a lot of Speedways and Super Americas which are Ashland Oil. I'm not sure if this is a regional thing but I know they have stickers on the pumps stating their gas has 10% ethanol. Now that I think about it, I think my gas mileage drop may be related to the ethanol content of their gasoline that I used the last few fill ups because I wasn't around my house when it came time to refuel. I filled up today with Marathon which doesn't have the 10% blend to my knowledge so gas mileage may improve this tank. I'll report back later.

I also see that our city driving is vastly different. I do have some open spaces that are rural 55 mph zones with a light every mile or so but most of my city driving is the 200 yard at a time to the next stop light variety in very heavy traffic from 6 am until 7 pm. If I take the city route to my local office, I believe there are at least 18 stop lights along the way by counting them in my head with traffic maxing out at 40 mph or so. I drive a bit for work away from my office and can go thru as many as 200 stop lights in a day if I stay in the city which could be local city driving or in a surrounding metro area as much as 125 miles from my office. Sometimes all of city driving is unavoidable due to lack of freeway access to some of my companys locations.

I try to stay out of the RL for work purposes but I really like to drive it vs. my company car. They fill it up if I drive the RL but no mileage paid since they provide a car. When I do drive it to work, my days driving can easily turn into 300 miles. Most weeks, I drive between 700-1100 miles between my home and our various offices.

You mentioned a lift kit in your last post. I too want one but I'm not looking for a couple of inches, I wouldn't consider turning the wrench to put it on unless it was at least 4-5". I know mileage would most likely suffer because of the tires that I would mount in place of the stock rims. I think this can be done retaining the original independent suspension. We would need longer lower arms for the suspension, longer drive shafts, and other parts that would be too expensive right now to have custom made. Maybe when the RL 15 years old, I'll weld on leaf spings and put Solid axles under it and lift it up for some serious off roading. Nahhh. Why mess with suspension perfection...

I just wanted to drop an update regarding my truck. I just got it back from the dealership. According to the dealership, my air conditioning was massively overcharged from the factory. They evacuated the system and recharged to the correct level. The service person mentioned that the amount of freon in the system was causing the A/C compressor to run overly hard possibly creating a decrease in gas mileage when the A/C compressor was running. They also stated that the output temperature of the A/C at the vents is a crispy 40 degrees now which was not what it was before. Hopefully, I will realize an increase in mileage. I will report back after my next tank of gas.

I also took it in to have my "boingy" stuts checked. Amazingly, they could not hear them. I can hear them constantly boinging all the time. I wonder how they missed that? Selective hearing I guess.

I feel real good about my RTS' performance. 2,380 on the odometer and it's all highway driving (55+mph) to and from work, A/C on and windows up. City driving sux tho.

I agree with the drop in mpg but got approx 5 mpg less after taking it to my Honda Dealer. He says it's Ethanol but I don't fill up with that mixture. Any ideas why my gas mileage is going in the toilet?:( :(

Check the following in this order:

Transmission fluid level - Only when hot, should be between the holes.

Engine oil level - Cold / hot, should be somewhere on the rough stuff.

Engine air filter - should look clean and make sure there's nothing that would block airflow.

Tire pressures - Should be checked cold (OEM recomendation is 32psi).

Could possibly be over tightened valves.

Interesting reading from Consumer Reports. (http://www.consumerreports.org/cro/cars/tires-auto-parts/car-maintenance/get-the-most-mileage-for-your-fuel-dollars-406/index.htm?resultPageIndex=1&resultIndex=1&searchTerm=camry%20mpg)

Air conditioning vs. opening windows.

Some people advise you not to run the air conditioner because it puts more of a load on the engine, which can decrease fuel economy. But others say that opening the windows at highway speeds can affect gas mileage even more by disrupting the vehicle's aerodynamics. Our tests show that neither makes enough of a difference to worry about. Using air conditioning while driving at 65 mph reduced the Camry's gas mileage by about 1 mpg. The effect of opening the windows at 65 mph was not even measurable.

I have an RTX so I do not have auto mode and my wife loves to run the a/c all the time it kills the gas mileage. I can get about 18.5 on the highway with the windows down, running the a/c I get about 15-16. :eek:

I drove back from the NC mountains yesterday (320 miles), and got 24.7 mpg for the trip. That was with the A/C running and cruising 60-70 mph most of the way. Can't complain too much about that. And I've only got 5800 miles on my truck. Hope MPG will be even better by the time I hit 10k.

Hi guys, bran new to the forum and thought I'd chime in.

I have an RTX so I have no auto setting but...

Always run AC on "max" as it recirculates the air so the compressor works less. Also, turn up the temp rather than turning the fan down. More air flow removes heat from the cabin just as well as colder air - perhaps better.

Driving with windows down does cause more drag that the AC at highway speeds. And don't wory about the AC in the city because the vehicles ECU will dissengage the compressor under heavy load.