Tires for truck

Jeremy · 05-07-2003, 12:58 PM

Does anybody know what size tires you can put on a stock 1990 Chevy Z71 silverado without having to lift it? I have 16x8 wheels and currently am running 265 75 R16 BFG All terrains but wanted to jump up to 275 or 285s in either mud terrain or all terrain.

willametteriveroutlaw · 05-07-2003, 01:47 PM

31 X 10.5 i believe. On a f150 you can go 33 X 12.5 with a little trimming. The wildcountry RVT's are a great multipurpose tire that should satisfy your hunting needs.

FastAction · 05-07-2003, 02:06 PM

16x8 wheels? you might get 32x 11.5's

ICHTHYDEMON · 05-07-2003, 02:35 PM

285's will fit on the stock rims,but won't fit the truck without some rubbing. I tried them on my 98 Z-71,and they rubbed pretty bad. Les Schwab switched them back out to 265's. You may try cranking your torsion bars up to get the tires to fit without rubbing,or trim the wheelwells.

redfish89 · 05-07-2003, 06:29 PM

I would stick with what you have. The smaller tires will save you money at the gas pump. Plus, they are better in the mud.

WaterDog · 05-08-2003, 05:47 AM

31x10.50 and 32x11.50 are "flotation" sizes for 15" rims. There is a 33x12.50 for 15" and 16.5" rims.

A 265 is probably as big as you can go. You might try a 255/85R16. It has an approximate dia of 33" but is only 9.5" wide. I would guess you'd still need to trim the front bumper but it should not rub on the torsion bars. Buddy of mine has a 99 burban and the 265's fill the wheel wells.

Also remember by going to larger than stock tire changes some things. A larger diameter tire will increaseyour rear end ratio. Meaning the engine will turn less rpm's at a given speed. This can increase your fuel economy but only to a point. Your speedo will also be off and it will read slower than your actual speed.

I run Schawb's TXR's. I get good mileage out of them and they a great in the mud and snow.

Here is a bit more info if you interested. :smile:

Tire fitment chart

Axle ratio/ tire size calculator

To calc the approx tire diameter:

chummer · 05-08-2003, 08:41 AM

I run 255 85R 16's on my 91 Z-71, I had to trim the plastic air dam a tad or else they rubbed when I turned, no other rubbing occured elsewhere. I've been told that newer chevys (98+)have a different wheel offset than the older chevys (88 to 97)

float2ber · 05-11-2003, 01:41 PM

WaterDog, what do you mean by "flotation tires"? I run 31x10.5's on my 15" wheels. The truck came with them so that is what I run. At 50 psi I seem to get good gas mileage and good tire longevity. Thanks.

Bill Monroe · 05-12-2003, 05:11 AM

I'd stick with what you've got, too...I had 275's on my 89 GMC and the new ones rubbed. When my son bought it, he jacked up the torsion bars a little to take larger tires. The changes in a frame that old weaked some welds and he had to have LS redo a lot of stuff...the 265's seemed fine.

FrogPond · 05-13-2003, 12:57 PM

I am running 285x75x16 Les Schwab Wild Country TXR's right now on my '98 Silverado. I really like the RVT's better though, less road noise & longer lasting. I trimmed the plastic air dam that is under the bumper a bit to aviod the rubbing. You don't have to cut very much off to fit them. Les Schwab should do this with no problem, that is who did mine.
I like the look of the slightly bigger tire.

If you want to see my truck, I can add pics.

FrogPond · 05-13-2003, 01:02 PM

oh, yeah...a couple more things:
1) my speedo is still right on (verified by the state police)

2) my milage did go down a little bit...but I also switched to a 3" Flowmaster muffler and now tend to drive with my foot in the firewall, because I like the sound...gotta love going to the drag strip!

ICHTHYDEMON · 05-13-2003, 02:15 PM

Frogpond,
I'd love to see some pics of your truck. I sold my 98 Z-71,and want to put some 285's on my 2500HD. I think the 285's will fit my HD just fine,I don't think I'll even need to do any trimming.

WaterDog · 05-13-2003, 11:00 PM

Most tires are size in metric now. Tires like 31's, 33's, 35's etc are called flotation because they do just that. Float, due to being wider than stock. Yeah some rigs come stock with 31's however if you look at many newer trucks and SUV's most are coming on 16" wheels and some on 17".

FrogPond · 05-14-2003, 07:07 AM

I will snap a pic tonight after work