The pulley always spins, whoever the compressor only rotates when the clutch is energized.


Want the best mileage?

Do your basic maintenance, keep the tire pressure adjusted properly, and drive like your granny. Pretend there's an egg under your right foot. Now, don't break it.

 

Easy now! I used all 10 of them. I didn't want the other 8 to get jealous. LOL Seriously, I try to give my results so others such as yourself can get a better feel where they are in life when it comes to this stuff. I don't know why my signature doesn't show on some threads.

 

I've got a few codes and other small problems that need fixing. But I still get 18-19 city driving. Don't laugh, but I have a goal of 30mpg. It's been done before so don't say its impossible. And the one I seen was a V8 automatic. I have an advantage with a 4.2 v6 5 speed.

I once got a car of mine from 7mpg to about 20mpg. Creative thinking helps.

 

I can honestly get about 16-18 with mine depending on city or open road but I don't drive aggressively either. I have the 5.4 with 3.55 gears and 2 wd. It started dropping this summer and couldn't figure out why. I did a complete tune-up, intake mod, 02 sensors and still off a little. Finally read about changing the cop boots and it was the ticket and mileage went back up. That was a cheap fix too..Tires always kept inflated to spec.
Now hook my trailers up and haul a car or the boat and I hit 10-12mpg area in no time....Or let my 19yr old son drive and he can get that with no trailer...LOL

Truck is stock with 255/16 tires, regular maintenance, and a cap covering the back. Superchip is no longer used and has not been in a few yrs since I don't tow as much as I used too.