does running the ac in your truck really use up gas?

 

The Short Answer is YES. BUT....... Several test have been done that prove the following:

Running the A/C cause a small load to be placed on the engine requiring more fuel to maintain the same speed.

Driving with your windows down creates a LARGE wind drag on your vehicle, placing a substantial load on the engine requiring even more gas to maintain the same speed.

Conclusion: Driving and maintaining the same speed while running the A/C with windows up uses less gas than maintaining the same speed with the windows down.

Once a vehicle is moving, over 60% on the energy required to maintain a given speed is used to over come wind resistance (unloaded and on a level road).

 

If your in stop and go trafic, thats when the a/c would be most likely to affect your gas mileage. Of course driving a Bronco your probably better off counting gallons to the mile anways.

 

[QUOTE= Of course driving a Bronco your probably better off counting gallons to the mile anways.[/QUOTE]

Hey, I resent that comment. I'll have you know that I can get 8 mpg if I drive it nicely (over bored heavily modified 460, 750cfm duel line double pump carb. etc.). BUT....If I stomp on it and smoke the tires off I can watch the gas hand drop 1/4 tank in 200 yards.

Buts whats a couple of (5-6) gallons per mile in the grand scheme of the universe???

 

It's generally less than 1 mpg drop on the highway.

 

Bottom line: Yes, there's no such thing as a free lunch.

 

thank you for the info

 

The tv show Mythbusters used two identical F150s(new) to do this test. The ac off did much better(both trucks had identical test conditions). But real world conditons will vary of course. I know engineers design trucks with the windows up for many reasons and use of ac is expected. You do have a Bronco(so do I)
so great gas mileage is a moot point. I understand that you want good mileage, you are better off making sure you are well tuned up and tires at the correct pressure. Use your ac if really needed, we have Broncos, we could go topless if we really wanted to!

 

actually, you have it reversed. the truck that ran with the a/c on went 13? i think miles farther on the alloted 5 gallons of gas than the truck with windows open and a/c off.

 

tjc transport,

I might have to reseach my info again. I can't remember now. I'll go to the Discovery site to check it out again.
But ac does draw more power from the engine, we should all keep are FORDS in top running order no matter if we use ac or not.
thanks again for the heads up.

 

yea, after i posted that, i went there to double check that i actually had it rite or if you were. but i could not find it.
i know that with my diesel and crown vic, using the ac will give better mileage than using the open windows, with the crown vic getting upwards of 75 miles more per tankful.

 

When it's 118 outside it doesn't matter if it costs more!

 

All I know is, for me its cheaper to go windows down than to buy the condenser to get it the A/C fixed!

 

sounds crazy to me. If I run my AC my Bronco does not have the power/speed it has with the windows down and AC off. That would tell me that the AC works the engine harder. How many of you experiance the same thing? If it works it harder I would think it would use more gas.

 

poffutt, I have the same problem. When the ac is on I am shifting from od the third and back much more on the highway. But with the windows down I can actually accelerate my speed in od on the highway.