I just put 16" wheelswithLT245/75R16 Toyo Open Country AT tires on my 99 Disco 2. Based upon feedback on this forum, I was expecting to take a slight hit to my gas mileage. I was a little scared of this since I only get 14.5MPG to start with on this poor California 92 octane gas. Imagine my surprise this morning when I filled up and found that my mileage has actually increased up to 16MPG! Most of my driving is freeway, going 70-75 mixed with a little round town driving.Since I put the larger tires on I have been careful to keep my indicated speed down by 3-4 MPH to make up for thespeedo error. I also accounted for the 5% speedo error in my mileage calculation. The Toyo tires have a slightly narrower treadsurface on the LTseries versus the P series tires, so maybe the reduced contact area combined with the really stiff sidewalls (10 ply)are more than compensating for the increased diameter. Whatever is the cause, I am certainly not going to complain!

 

Thats a nice improvement in Mpg. The taller tires makes the engine rev. less on the highway by about 300 rpms, at least thats what I noticed with my 245-75-16 BFG A/Ts. How much air pressure are you running? My tires will take 75psi, I have them inflated to 45 psi.

Willie

 

I actually have not checked the pressure. They are rated for 80 PSI. The shop said they would put 50 in them, but I need to check and see what they actually put in.

 

I have BFG A/T's 245/75/16(E80psi) and run them at 32 to 35psifrt with ARB and winch, rear 38psi to 45psi withgear.

I have found that my speedometer isright but the miles shown are
6.5% off (lower), I used my GPS.

 

You are not necessarily getting a real improvement in MPG. You tire/wheel swap may have created an error in the speedometer/odometer. I'd check it against a GPS for reference. I think you'll discover your speedometer is reading several MPH high which means your odometer is recording more miles traveled than actual, and introduces significant error in you MPG calculation. Just an educated guess based on experience.