Here is my problem. I have a 3.31 rear end on my truck I got a 235/70/16 set of tires on it. This size is 29 inches in diameter.

I went to Ford and talked to them. A Ford mechanic says that I should not put tires on that are any more than 1 inch larger than these. His reasoning is, that since I have an automatic transmission the tranny will slip and wear out faster, especially if I put 32's on like on my old truck.

I have been looking at other options, like putting 18s on it and street tires but I constantly find myself dreaming of going offroad again.

I am wondering if I should go with 235/75/16 A/T tires which are 29.9 inches and still keep the transmision alive.

According to http://www.4wheelparts.com/Tirel_gear_ratio.asp
(thanks justin)

a 30 inch tire with 3.31 rear end will get the best gas mileage.

I guess what I need is just a confimation that it would be OK to put 30 inch tires on and that I wont kill my truck.

BTW, I do have a 4.2 engine with an auto tranny, no more manual

Thanks

__________________
1999 F-150 AirRaid, 4.10 gears, tint, superchip, see my gallery for more.

well i know a person who had 38's and stock 308 gears and aauto didnt seem like it was hurting it but the truck was a pos from the begging and the kid was pretty dumb

__________________
all bow down to the one who choses to shift cause i am a Crazy Gear Rower,
supported by "ares wipe when that fart becomes a,squirt there's ares wipes"

haha im not goin that far

__________________
1999 F-150 AirRaid, 4.10 gears, tint, superchip, see my gallery for more.

its not gonna hurt it m friend here has an auto with 35's on emm and he still has his original gears and hes had the truck for 5 years and no problems other than he blew a tire off and cant drive it right now, you should be fine man

__________________
"IF IT CAN BLEED, WE CAN KILL IT"

lol yea but he prolly has like 3.73 or somethin.

im thinkin that since i drive mostly on the highway and drive about 30k a year i will just put my leveling coils on and then put 29.1 inch BFGs on

__________________
1999 F-150 AirRaid, 4.10 gears, tint, superchip, see my gallery for more.

The A/T's will be great for you it sounds like

__________________
98 xlt, dropped 3/5. 17in. CHROME Cobra wheels wrapped in 255/50/17, billet grille, dumped flowmaster 40 series, clear corners, euro tails, indiglo guages, TWEED Interior, painted interior, silver flame pinstripe, 5% Limo tint all around, K&N, Viper alarm, 60/40 to bucket conversion, 4.10 gears
SOLD 10/29/03!!!!!!!!!!!!!!!!!!!!

2003 Dodge SRT4


Mopar Stage 1 | Mopar STS | BDJ's exhaust | HKS SSQ BOV | IPP CAI | ATP Upp | Autometer pillar pod with dual gauges | DC sports Strut bar | 9007 PIAA Extreme whites | Eurolite 893 Fog lights | Titan turn signals | Clear side markers | Intercooler Neon | Viper emblem | Exel Ennio wheels | MM inserts | Catch Can | Custom racing stripes |More to come.