Fuel Economy on a lifted Jeep?

Question

I have a 2000 Wrangler Sahara with a four inch lift and 33 inch tires, ever since I put it on I've been getting really bad fuel economy(as expected), any suggestions on how to get it up a little. I'm thinking about new headers and a new cat-back exaughst which should give me more horsepower too. What else can I do?

Answer 1

If you're worried about fuel economy, you have no business driving a lifted jeep.

Answer 2

K&N makes a good performance filter and filter charger system that can give 1-2 mpg increase. However not all experience this gain,the results are mixed. Have you considered a fuel ijector cleaner and thottle body cleaner both of which can help. Good move to go to headers and performance exhaust that will really make it snort. The headers and the performance exhaust will yield about a 25-30 HP gain the K&N will add another 14-17 HP. Most often this will be noticed under full throttle. Have you considered a PCM to reprogram your computer settings? The PCM will save your stock settings if you decide to return to that. The Pcm will adjust such things as air fuel ratio ignition settings and shift points according to info you give the PCM. It's not cheap but combined with the above mods you will have one mean machine. Anytime you make mods of any kind there is a price to pay,if you don't make the other mods at least do the PCM, by itself it will help performance. Oversize tires changes everything . Without changing the parameters in the computer to make up for the difference in tire size it will affect trans,air fuel ratio throttle body etc.

Answer 3

you should have all the parameters changed in your computer to recalibrate for the new tire size but the major problem will still be there as for the tire size this will change your torque which
is what you are needing to keep the bigger tires moving
when you lift a vehicle and put on bigger tires you change all the factory variables that they designed your vehicle for and your vehicle is not geared for the tire size you put on
you should change the Axel gearing and that is going to be a expensive endeavor a horsepower upgrade will help but you will still be burning a lot of fuel to get the jeep moving
I own a 85 cj 7 wide body with 40 in gumbo mudders and have to run 4;56 gearing to keep it in the proper torque range for the engine
and yes it still has the 258 straight 6 cylinder in it and does just fine
the gearing change probably will be the same cost of a header and exhaust system
you should have a reputable shop do the gear change because there are allot of adjustments to the gears to put them in properly
with the ring and pinion for back lash and other settings
if you are really mechanically inclined you could do it but be very weary hope this helps

Answer 4

I hear that a K&N air system gives you a little more horsepower and a little better gas milage.