I'm just green to the forum, and I know this question has been asked alot, I've read all the posts in the tire forum, but I'm going to ask anyways. I'm the new owner of a 1998 F150 Reg Cab 4X4. What is the biggest tire I can fit on this truck. Is it the same as the S-Crews or E-Cabs? 285/75/16 or should I go a little smaller? I would like to keep the stock wheels for now? It has the factory 235/70/16 on it now. Any help would be apreciated! I'm going to love this site!!!

P.S. I would like to get tires ASAP! Tomorrow, so any help would be nice!

Thanks
Adam

 

You can go as big as a 305/70/16 if you want, which is essentially the same height as the 285 but 12.5 inches wide instead of 11.5. They will wear in the center of the tire also because it is such a wide tire mounted on a narrow rim. I personally have 285's on my 97 and think they're great. Just remember that when you go to the larger sized tire you need to recalibrate your speedometer. This is easily done on 97's and 98's by changing the vss gear in the tranny. It's a $5 part and takes 30 seconds to change out. When I went to the 285, I got a new gear with 2 less teeth than the old one, and now my speedo reads perfectly again.

 

Thanks for the response. So I can go with the 285's without any other mods? And how do I know how many teeth I will have to go down? What did you start with?

Thanks for the help!
Adam

 

anyone else with suggestions?

 

Yep 285's will fit with no problems. When you go with bigger tires, like 285, you subtract teeth to get your speedo right again. My original had 21 teeth and now I am running one with 19 teeth, but they are pretty much truck specific, you could have more or less teeth than I did, but you will still probably get a gear with 2 less teeth nomatter how many teeth is on your original.