Does having the A/C on make that much of a difference?

[Kamal]

I knew the compressor of the A/C unit on your car turns off of a secondary belt powered via the engine causing a low gas mileage but damn I didn't realize how much it was.

This past weekend, it was cool enough to drive without having the A/C on and so on our monthly drive out Mid-West, Sugana and me had the A/C unit off the entire drive.

Usually my car give me between 335 - 345 miles to the tank before my low fuel light comes on. On Friday, my low fuel light came on at 393 miles

Way back was even better, low fuel light came on at 398 miles and we drove on until 410 miles were over and we got gas.

Both times we left the A/C off.

That's a massive difference in consumption just to have your A/C on.

[Bryanw24]

Re: Does having the A/C on make that much of a difference?

Thank your lucky stars Kamal. We don't have that luxury here in Florida. Its still almost 90 at night.

[geoffgulley]

Re: Does having the A/C on make that much of a difference?

^^ I heard something on npr over the weekend that with the ac on you lose between 5 and 10% (I think) per gallon mileage... but it's better than driving with the windows down. I forget who it was and who he was with.... might have to surf by npr's site and look that up again.

[geoffgulley]

Re: Does having the A/C on make that much of a difference?

ahh..... OK it turns out the discussion was about hybrid cars and trucks. get this.. running the AC in a hybrid vehical can decrease mileage by up to 27% while in a regular car/truck it's between 2 ot 5%.... at least I got the 5% right.

http://www.npr.org/templates/story/story.php?storyId=5620876

[Kamal]

Re: Does having the A/C on make that much of a difference?

wow 27% is a lot, though even with a 27% loss, I'd imagine that a hybrid will still be better off than a regular gasoline car. I'm considering getting the '07 Camry Hybrid considering the amount we drive everywhere. I know it's not the most exciteable automobile but considerng 700 miles to the tank, it's an awefully delightful $$ saving.

Moreover, if its cool enough outside, you cab keep the A/C off and leave the circulation on "Fresh" as opposed to "Recirculate" and still have a stream of cool air coming in.

[hambino21]

Re: Does having the A/C on make that much of a difference?

Yeah it definitly makes a difference. you can tell just by how much horse power is taken away . My car is never near fullest potential when the AC is on.

[Kinetic]

Re: Does having the A/C on make that much of a difference?

Not only does it lower your mileage, it also makes you lose performance regarding top speed and acceleration, and it also stresses the engine more.

But then you take examples like mine : a couple of months ago I had to drive to the interior, it was a 300 mile trip under temperatures above 100º F, in a 10 year old car with no A/C...I survived, but barely. I guess it´s not so bad if you don´t hit the gas too much.

[demonAfro]

Re: Does having the A/C on make that much of a difference?

If you want to make up for the A/C just sit yourself at 60 mph in the low pressure zone behind a lorry. Managed to get from 50 to over 70 miles on an eighth of a tank.

[day_for_night]

Re: Does having the A/C on make that much of a difference?

^^ I heard something on npr over the weekend that with the ac on you lose between 5 and 10% (I think) per gallon mileage... but it's better than driving with the windows down. I forget who it was and who he was with.... might have to surf by npr's site and look that up again.

actually, its more fuel efficient to drive with your windows down than with the a/c on, or at least thats the result they came up with on mythbusters (tv show on discovery channel)

[Kinetic]

Re: Does having the A/C on make that much of a difference?

actually, its more fuel efficient to drive with your windows down than with the a/c on, or at least thats the result they came up with on mythbusters (tv show on discovery channel)

Exactly. Driving with the windows also wastes fuel (and diminishes performance) because of the resistance to air flow, but it?s always been my understanding that having the A/C on wastes more fuel, and, don?t forget, is more stressful to the car?s mechanics.

[clintlove]

Re: Does having the A/C on make that much of a difference?

I would love to keep the a/c off in my truck, but temperatures here hit high 90's low 100's throughout the summer. I'm sure it would save alot of gas, but I'll never know.

[MJDub]

Re: Does having the A/C on make that much of a difference?

Yeah fuck having the AC off. I'll freaking roast if I do that.

[picklemonkey]

Re: Does having the A/C on make that much of a difference?

MythBusters did a test on this. I think they came to the conclusion that if you were going over 60mph, it's more economical than having your windows down due to wind drag

[TomTom]

Re: Does having the A/C on make that much of a difference?

Even if it costs a bit more fuel, no reason to turn it off when it is hot.

[Lrn]

Re: Does having the A/C on make that much of a difference?

depends a lot on the displacement of your engine