Will leaving the Air Conditioner turned off in my car better my gas milage?

Question

I heard that doing things like leaving the AC turned off in your car, goin only 60mph on the highway, and keeping your tires fully aired won't cause your engine so work hard and burn less gas. Is this true? I hope this will reduce my trips to the pump. My car currently gets 32 miles per gallon on the highway, which is decent.

Answer 1

Yes, but not by any significant amount.  The AC takes up very little power.  Opening the windows wastes more gas than running the AC when you're on the freeway.

Going no more than 60 and keeping your tires fully pressurized are very important and will save you gas.

Answer 2

i have used this experiment on trips with my telemetry. it saves about 2 miles per gallon on cruise control. it isn't worth it if it's hot!

Answer 3

I assure you, A/C runs off the engine - not the battery.

All the things you said are true.  

Beware opening your windows though.  It makes no difference at low speed (around town) but at high speed, it hurts your fuel economy just as bad as running the A/C.  In that case, best is fan/blower on, windows closed.

If you want even more ideas for saving gas, look up "hypermiling" - but some of their ideas are just crazy.

Answer 4

Yes, it's true, not turning on you ac puts less drag on the engine; hence good gas mileage.  Another tip, if you drive the speed limit in town, the traffic lights are set up in your favor so you won't have to constantly stop.  Ever have one of those days where you catch every red light?  Well if you catch the lights when they change go green, and stay at or under the speed limit, you will mostly likely catch every traffic light green.  I live in Florida, not having the ac on is a killer, so I run it.  

Peace

Answer 5

yep thats pritty much true. and keeping your car mantained /tuned.

Answer 6

I got 30 mpg with it on, 38 with it off.

it makes a difference.

no, the AC does not run primarily off the battery; it's operated by a belt, turned by the engine.

Answer 7

yes they all will help, along with regular maintenance-changing oil, air filter, fuel filter, spark plugs as recommended.

Answer 8

No I doubt it. Your AC runs mainly off the car battery. Plus, if you roll down your windows (I'm sure you will since it's summer) then your car is less aerodynamic (because it gets more wind resistance) and it hinders your gas mileage. So it's best to just keep your AC on low (and recirculation). The other things sound like they'll help though. I've also heard making as many right turns as possible (rather than left turns) uses less gas.

Answer 9

sounds like a corolla..with the heat its going to irritate you more..plus having the window down creates more wind resistance making your engine work harder, and decreasing fuel economy

Answer 10

The a/c being off will help with the gas mileage unless you open your windows.  Then the air causes additional wind resistance and will almost negate anything you might have saved by not using the a/c.  So basically if it's hot outside, use the a/c and keep comfortable!

Answer 11

Yes, all true, but if it's unbearably hot and your driving 60 mph with your windows closed, why not use the AC?

Answer 12

Yes to the A/C being turned off.

Yes to limiting your speed on the highway.

Yes to keeping tires properly inflated.

But if you limit your speed and then drive with windows open, you change the "drag" coefficient, which can hurt your mileage sometimes.

Answer 13

yes, depending on the vehicle, you can gain a bit with it off.

Better yet to drive between 55 and 59 MPH. This is the range most vehicles get their best mileage. Anything over that and mileage decreases exponentially lower than speed gained. Tire inflation is very important.

I had my exhaust system totally redone. This time using the same diameter pipe from the manifold throughout to the tail pipe end. This kicked me up over 3 miles a gallon. Manufacturers reduce the pipes diameter for cost savings on trucks which is what I have. New plugs and plug wires also helped.

My truck went from 10.5 MPG to between 15.5 to 16 MPG with the simple changes made.  Also, a K&N air filter increased mileage almost .5 MPG.

Answer 14

Yes, those tips will help. In addition, the best time to put gas on your car is early in the morning (the heat of the day swells gasoline and you actually get less into your tank for the same price if it's really hot outside). Also, don't let the hose fill up your tank too fast (use the first tab option as opposed to the third one).