Just wondering...I have not made up my mind yet on tires. I am thinking about going from the 265/70/17 to a 285/70/17 or 33/12/17.

Will I loose a fair amount of power (I expect to loose some but don't want to loose alot like I did on my 88 F150 4.9L w/ 31's)??

How far off will the speedo be??

Should I go larger or stay with the stock size??

mhussey,


I went from 245's to 285 75 16's and noticed a little power loss but definently nothing so noticible that I would regret it. I also have 5.4 but still dont think it will make much diffrence, and have not noticed speedo change I would go for it.

Thanks for the reply, that is what I would have liked to hear. Anyone else have any info or input on this topic??

Same with my truck, I went from a 245/75/16 to a 305/70/16 and did not feel any power loss (this is dyno tested by my butt metter) you should be fine! what gear does your truck have I have a 3.55 rear thats what you want to look at

I have a 97 w/ ORP and 3.55LS rear end. The motor is the 4.6L bored .030 which I think may now be a 293 (4.7L)?? I am putting on a Gibson Split rear and a superchip. Someday I may replace the stock air box with the Air Force 1 unit.

mhussey, i have reqad your threads and i have some questions for you. i have a 1999 f150 4x4 with 265x70x17s. i too want bigger tires. i noticed that you mentioned 285/70/17s. who makes tires that size? i have been looking all over. i have only found 285/75/16s, no 17s. also, you mentioned 33/12/17s. do you know a manufacturer that makes those? i only know of 33/12.50/17s. my truck is stock. i want bigger tires without lifting it. can you give me any info?

BF Goodrich just came out with a 285/70/17 in the Mud KM tire.
You can put 33's on your truck, but you may have to crank the torsion bars alittle. And if you have the molded mud flaps; you'll have to trim those too. I have the ProComps Muds (33/12.5/17) and I did loose alittle performance and about an average of -.75 MPG.

Thanks Jupitrak...I guess "a little" loss in performance an 3/4 of a mile per gallon will be worth it.

blove- I am thinking about the ProComp Mud Terrain's in the 33/12/17. Procomp also makes an A/t in this size. Goodyear also makes a 275/70/17 Wrangler MTR. I am thinking about the ProComps because they are buy 3 get one free from 4wheel parts. Hope this helps.

Jupitrak...sweet truck! I would like my next truck to look just like yours.