Lift Height vs MPG?

[Kimber6331]

Hey guys not sure if this topic has been discussed, but does anyone know how much, if at all, suspension lifts effect gas mileage? I'm assuming that bigger tires, different tread, pressure, height, weight. etc would effect the MPG. I'm asking because I am considering buying remanufactured/ rebuilt engine for my xj to keep her as my dd instead of buying a new car. Before I buy a lift kit I was concerned that it would hurt my MPG and my wallet for gas. Any input is appreciated, thanks guys!

[prerunner1982]

I think bigger tires will have more of an effect on MPG than the lift would. Theory is that the lift will cause more air to go under the Jeep creating more drag. However, I think the heavier tire with more rolling resistance will have a larger impact on MPG.

[bluedragon436]

I don't know what the real loss is... But I know me running my 7+" of lift with 33's, I really haven't lost too much on the gas mileage end of things.. I mean I know I've lost some, but I gained some back when I did a full tune up on the engine. It also depends on high large of tire you are wanting to run as well as the tread type... I know an A/T will run better than a M/T, and I know a smaller tire will do better than a larger tire... So if for example you are more than happy just having a little better stance and use out of your XJ, than you could go with say a 4.5" lift and 32's, and not really suffer too much on the MPG... I mean if you just want a little bit of change you could even go with a 3-3.5" lift and 31's and not notice anything at all really MPG wise... What kind of mileage to you run on average a month??

[Mudderoy]

Hey guys not sure if this topic has been discussed, but does anyone know how much, if at all, suspension lifts effect gas mileage? I'm assuming that bigger tires, different tread, pressure, height, weight. etc would effect the MPG. I'm asking because I am considering buying remanufactured/ rebuilt engine for my xj to keep her as my dd instead of buying a new car. Before I buy a lift kit I was concerned that it would hurt my MPG and my wallet for gas. Any input is appreciated, thanks guys!

Just after my lift and tires, I started collecting MPG data. I jumped the MPG up about 2 mpg by going to 4.56 gears. Since then nothing I have done has affected the gas mileage more than a fraction of a mpg. That is custom front and rear bumpers, sliders with frame stiffeners, and even taller, wider tires.

There has been a steady decrease over the last year, or so, which I'm thinking it just the engine getting more wear and less efficient.

I know the common thing people say is weight, air flow etc... and I'm not saying that is wrong, I just haven't seen it on mine.

I'm about ready to put in a new 4.0 (4.1 actually) in my Jeep and I'm hoping to see a bump in the mpg due to everything being new and also the air flow through the engine should be much improved.

The best thing to do is collect a lot of mpg data. Every time you fill up. I wish I had before the lift and tires.

[Kimber6331]

That's what my assumption was. I'm pretty sure Im now running around 20 mpg highway and i have to guess at around 13-14 mpg city. Its an 01 xj with 255,0000 on it. And honestly I was only thinking of getting a 4.5'' with 32's. And if I buy a new rebuilt engine 4.0l from quadratec I'm assuming that should improve the mpg. with or without messing with gears.

[cantab27]

re gear would help...but really jeep and petrol economy don't really go together...tis a jeep it will drink gas...they still make the stuff ........runner82 gets good results on his....buy a cheap dd and put the rest of the coin into mods for the jeep..........just my 2cents...carry on................

[OrangeXJ]

you own a tj you don't have 2 cents to spair

[4.3LXJ]

Lift a rig and put bigger tires on it, yes you will see a drop. But the question is, how much? Speed is a real enemy on lifted rigs. You are increasing the front profile and will have to move more air, under, over and around and it will affect gas milage. I notice my milage goes down noticeably above 65 mph. I currently have 8" of lift and running 31s with 4.10 gears. I don't have the 4.0l, but my milage is 16 mph commuting and 18+ highway.

[Carves]

The more vehicle height the more drag .... whether it be a lift and underflow issues ... or a bunch of junk up on the roof.

... but as already mentioned ... The effect is relevant to vehicle speed ... and for the most part, the fuel cost is minimal in real terms e.g.

... at stock height with bulky bedrolls and a spare wheel on the roof .... I lose 1mpg on the highway ..... pfftttt - big deal ... so each tank of fuel till the end of the journey will cost me, maybe an extra $5.


X 2 on oversized wheels & tread patterns, etc., being a bigger issue .... but if you need big wheels or a lumpier tread pattern to suit your common driving scenarios ... then the additional fuel cost - is the price you pay for having them. ;)

[cantab27]

you own a tj you don't have 2 cents to spair

with two more cylinders ...loves gas..don't care still gonna drive it...as you were