biggest tires??

[99Zseven]

I have a 99 Z71 and I was wondering what the biggest tire I can have on the truck with out a lift?? I was thinking of getting 33/12.50... would that fit ok??

[jeverett]

I don't think that'll fit.. I would try a 285/75 instead. You might get lucky and can squeeze a 305 under there, but without a lift, I seriously doubt it. Maybe turn the torsion bars 2 or 3 rounds and that will help a little, But I do know for a fact that 285's will fit.

[mjgjr72]

285/75 has a diameter 32.9 " and is actually a fraction larger than most 33's which are about 32.7. but a 12.5 is more than an inch wider and will not fit on stock rims . your truck came with a 245 's i think which is a 30" diameter tire you can probably fit a 265 wich is just under 32" diameter but if jeverett knows for a fact a 285 will fit than a 33 will .just get a 10.5 or 9.5 or get a junk the size u want to try and mount it on the front and see if it hits on turns.make sure u bounce the front end and have room for the new tread.

[99Zseven]

thanks for the replies. I am going to get 15x8 rims. would 12.50 fit on those??

[mjgjr72]

no you need at least a 8.5-11 inch rim width
10.5 need 7-9, 9.5 need 6.5-8.5
12.5 have a 12.4" tread width and if you are pushing the limit on tire size the corners or the tread will catch on turns.

[jeverett]

BE SURE to check your backspacing... Without the proper backspacing, no rim will work, regardless of tire size. Also, 15 inch rims wont fit on the new body style trucks, no matter how hard you try....the brake calipers will not fit inside the rim, so you have to get 16 inch rim. If you want to use 33x12.50's, I personally would go with a 16x10, but they will work on an 8" rim. I have seen 285/75/16 BFG All Terrain's on a 16x8 rim work perfectly and look really good also. Every brand of tire is different, so some tires will work, while some won't. I've learned many a things working @ a tire shop.

[99Zseven]

thanks. I appreciate the information.

[Tenman]

I just put 285/75/16 BFG All Terrain's on my 02 and I had to have the torsion bars turned up. I have alot of people comment on how good it looks and I could not see putting anything bigger on there.

[mikes z71]

i have an 07 z71 classic i have 305/70/r17 and they fit fine i had to do minor trimming under the wheel well on the front driver side and that was all

[J-Ri]

[quote=jeverett]...15 inch rims wont fit on the new body style trucks, no matter how hard you try....quote]

Is that trying with an angle grinder? 15" will fit on the '86 body style with the heavy duty brakes, but caliper and backing plate modification is required. I converted my truck to 4 wheel disc brakes and had to trim all 4. If I had to do it over again, I definately would have paid more for 16" tires.

About the rim width, any 16" tire will fit. A wider tire on a narrower rim will cause much faster wear in the center of the tread. I had 285/75/16 on my stock 16x6.5" rims(I think yours are 7"?), and the center wore down to 3/32" and the outside was not worn much at all, but that was at 45 PSI normally, and 65PSI with a load in the back or pulling a trailer. I have a friend with a jeep, he has 33x13.5x15 on a 15x8 rim. He keeps the pressure low, and the treadwear is fairly even. How low you can keep the pressure on-road depends mostly on the weight of the vehicle.

If you're planning on offroading, go with the narrowest reccomended rim for the tire size. It will put more outward force on the bead, and can keep you from poping one off the bead if you rub it too hard on something.