Contour Enthusiasts Group Archives Forums General General how much energy does "A/C" save over "MAX A/C" ?

My bro works in heating and cooling. Says WOT hurts air conditioning compressors. Supposedly our computer cuts the A/C compressor at WOT.

Car companies design their pickups to be more aerodynamic with the tailgate up.

Hop in the back of a p/u and run her up to 65mph and tell me if you still believe this. :p

I tried the tailgate up/down experiment. The tailgate down resulted in a bit better mpg due to reduced drag (quite the contrary to the "bubble theory").

But, I'd rather have the better structural ingegrity of the tailgate up and not have a 75lb piece of metal flapping around on the back of my truck at highway speeds endangering other motorists (came to my senses after hitting some bigger bumps and watching the gate jumping about).

IMO, the "bubble theory" was cooked up for liability reasons (see above).

BTW, the compressor does shut off at WOT on our cars.

Switched A/C

...Ed

FWIW, A/C cuts out at WOT. Some cars nowadays use electrically-powered AC, therefore reducing/removing the drain on HP.

Truck companies do wind tunneling testing with the tailgate up. There is more R&D than you think. Trucks get better MPH with it up.

here in texas, we dont care. the ac runs 11 months of the year. its hot!!!!!!! i turn on the ac to high and then try to start the car. i want the starter motor pumping freon! i'll buy more gas just as long as i am comfortable.its all about me.

I don't doubt at all that car companies put their trucks in the wind tunnel and make them as aerodynamic as possible. But, the tailgate still generates drag.

Have you ever noticed the trucks in the Craftsman Series? Why would they have covered beds if they could have better aerodynamics using the "bubble theory" and open beds with a tailgate?

Also, take a look at the Baja trucks of all classes. I can't remember seeing a single truck running with a tailgate.

I'm assuming you mean MPG?

Sorry, but that is incorrect. If that were true, then all of the people I've seen with the same results I had and everyone who have gotten better mpg when adding a tonneau/cap/bedcover would be lying.

In any case, the increase in mpg is small and not worth creating a hazard for.

Electric A/C doesn't remove the HP drain. Moves it to the alternator. However, as you said, it reduces drag because the electric motor driven A/C runs at constant speed, so a more efficient compressor can be used for that single speed. Belt driven compressors have to supply A/C at idle and at high rpms. You suffer low performance at idle and high drag at high rpms. so electric drive evens out the load. Of course, now you will need a 200 amp alternator.

We already have a switch to turn the A/C on and off. Its located above the radio, its one of the round knobs... Whats the point of that switch you have the link to??? -Nick