Who has accurately figured out their change in mileage after doing a lift and going to larger tires?

I just put 195/75/14 tires on my Gl turbo and then went out on the highway with my GPS and found that the change was five miles per hour difference. A GPS is very accurate.

the lift won't change your milage, but the tires will, i have figured, i believe its SubaruJunkies math and its been comfirmed on a rock crawling site with a calculator that going from stock to about 28 the difference is 12%, so to go 70 you are only going 55 and at 70 you are around 92. there are plenty of sites that will do the conversion for you, just google online conversions and there should be a site that has it, it just needs to be found in all the other conversions.

My mileage went in the toilet, and I can tell you that Bugaru had the same effect. My car was 2WD, with stock tires of 175/70r13's. I have a brand new weber, and before the lift and tires I got 32 MPG on the freeway. Now with 215/75r15's I get about 17 MPG. Bugaru with his 205/75r15's gets a little less than me at about 16.... mostly due to his crappy hitachi, and 84 4 speed trans. I have bigger tires and more wieght, and I still get better mileage with my weber.

 

There's really not much you can do about it, except build a higher compression engine, putting out more power. The tires are tough for the little 1.8 to push down the freeway, and your mileage is going to suck. That's just how it is. It's still better than most big trucks tho.

 

GD

this is a link to a calculator that will tell you your speedo change for every mod you can think of!

http://www.subarubrat.com/Calc.htm

I already know mine - it's 19.2% It's not hard to figure out on your own with a little math. Basic percentages, and a little geometry is all that is needed.

 

GD

Thanks GD

I was looking for MPG change not MPH, At this time I am not willing to give up MPG for groud clearance, A 5 MPG drop is too much.

The lift itself will not really impact you to a great degree. Slightly larger tires will not hurt and if you do highway cruising the lower RPM can help. But that is a thin margin, go up very much and you will start dropping.

Here's another one. It lets you go from Pmetric to inches and visa versa. tyre calc. Tim