Poor mileage after lift and 37" tires?.

[HiRoller]

Hello I am new to the forum and I have a question already. I was happy with the mileage with the radix supercharger and headers with B+B catback exhaust,but when I installed the lift and 37x13.50x18 toyo MT's my mieage went to half. does anyone know what to do? I was thinking the big rubber was lugging the motor and maybe a gear down in the rearends would help. Appreciate any help I can get.

[HiRoller]

Hello I am new to the forum and I have a question already. I was happy with the mileage with the radix supercharger and headers with B+B catback exhaust,but when I installed the lift and 37x13.50x18 toyo MT's my mieage went to half. does anyone know what to do? I was thinking the big rubber was lugging the motor and maybe a gear down in the rearends would help. Appreciate any help I can get.

[DRTYFN]

That's really not that much extra rubber and the Toyo MTs aren't super aggressive so you shouldn't have dropped off by 1/2. Are you being heavy-footed? What psi are you running your tires at? Is the weather especially hot and you're using the a/c alot?
I've run 37" Iroks and MTRs. The Iroks, being a super aggressive tread and a heavy tire, offer lots of extra rolling resistance and unsprung weight. They knocked off 2-2.5mpg from highway driving. The MTRs are a relatively aggressive tread and weigh several pounds less. With the MTRs I usually see maybe 1-1.5 mpg difference from the stock BFG ATs.

[HiRoller]

I am running 32 psi as advised by Toyo for my application I do drive somewhat fast but I drive a lot of kms. and usually on cruise. the last mod I did was the tires and lift. Before that I averaged 18 Ltrs/100 kms, now I am at 30Ltrs./100Kms. I have a PCM coming from Nelson and it should correct my speedo but my fuel is really going somewhere.

[KenP]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by HiRoller:
I am running 32 psi as advised by Toyo for my application I do drive somewhat fast but I drive a lot of kms. and usually on cruise. the last mod I did was the tires and lift. Before that I averaged 18 Ltrs/100 kms, now I am at 30Ltrs./100Kms. I have a PCM coming from Nelson and it should correct my speedo but my fuel is really going somewhere. </div></BLOCKQUOTE>Raise the pressure. You're low. Look to around 40+.

[DRTYFN]

I'm with Ken. At least 40 psi.

[JamesT]

I run a 6" lift with 38 15.5's Toyo MT's and I get 11 mpg. I do have a Hypertech Programer that does make a differance. To prove it to myself I returned all settings to stock and drove for 2 weeks. Mileage went down to 8.6.

[HiRoller]

Thanks for the info guy's. I will pressure them up and see what happens.

[JamesT]

Phil, The Max now has Nitrogen to fill tires with...FYI