Up or down MPG

[JkP]

Just picked up a 2wd sport trac and plan on either lowering or raising it. Id like to raise it but im kinda worried about the gas mileage. Was hopeing to get some estimates of around what id be looking at.,

2 inch drop with 20s = MPG?

2 Inch raise with 18s and 32 inch tires= MPG?

 

[mikekristine218]

Take it from me, I had my 2003 XLT on a 2" Torsion Twist and it handled and rode horrible. I also noticed that running 285/75r16's also hamperred my fuel milage.

I am currently lowered 3" under stock using a Explorer Express kit and it handles and rides amazing. I do not have oversized rims currently however I plan on running 18" rims and will match the tires to keep the same size/height that I currently have therefore it will have no change in my current fuel mileage.

He is a pics of how it sits lowered 3"

http://www.flickr.com/photos/49653486@N05/4564553231/

 

[JohnnyO]

As far as tire size and gear ratio, what matters is the OD of the tire and if it is larger or smaller or the same as stock. Wheel diameter itself doesn't matter. If you go to a larger diameter tire you have to take odometer error into account when calculating mpg. If your new tires are 10% taller then your odometer will read 10% less miles than you are actually traveling. That said, when I put taller tires on my old Sport Trac the mpg was still worse because the engine was operating at less than a peak efficient rpm.

Other things being equal, a lifted truck will get worse mpg than a lowered truck because of more driveline friction and more wind resistance.

 

[JkP]

what mpg are your averaging lowered? also can you link me to the lowering kit

 

[JkP]

also can someone shoot an estimate for raised? are lifted on 33s averaging aroung 15? and around 20 for lowered?

 

[JohnnyO]

also can someone shoot an estimate for raised? are lifted on 33s averaging aroung 15? and around 20 for lowered?

For highway mpg that sounds about right. I had a TT and shackle lift on my old '05 with 32's and 3.73 gears, 16 mpg was the best I ever saw.
My '08 V6 is stock height with stock size tires but has a K&N and Gibson exhaust, I would get 22 mpg (it's rated at 19) on a level road with the cruise set on 65 mpg. I lost about 2 mpg recently when I switched to A/T tires from the stockers. More rolling resistance. The OE tires weren't worth crap in snow though.