4.5" lift with 285/75/17 tires ??? Tires too small

[ledoux79]

I had one of my tires throw a belt so now I need tires. I had planned on a lift later with tires and rims but all has changed with one tire out and the rest are wore down pretty good.
I am looking at a 4.5" lift, and can't do rims and tires. But I am wanting to put a 285/75/17 toyo MT on my stock rims. They measure out at 34.2" and can't find much on the search of a 34" tire on stock rims with a 4.5" lift.
I have only seen a couple people put a 35x12.5x17 on stock wheels. I would do it but for the price of tires I want them to last as long as possible with out wearing out the center because the rim is so narrow.
Let me know what you think.

[Karls03]

Through metric conversion, those 285/75-17s ONLY measure 33.83. Not that I am a tire dealer/guru, but I'm not familiar with that size, most are a 70 series in a 17 inch wheel. If it's a 285/70-17 it's only going to be 32.7.

The metric conversion for the 35X12.50 is 315/70-17 or 315/75-16. This is probably while your 34 inch search came up empty. These tires spec out at 34.6-ish.

For max tread on the ground run those 285s on a 9 or 10 inch wheel or rub chalk across your tread when they ARE NEW and see how they rub off. Play with the psi until the chalk is almost all gone. This PSI will be WELL below the MAX PSI on the sidewall. Duh, the keyword is MAX after all. Narrow wheels squeeze the tread up, don't be surprised if optimum PSI is 35~45 range.

Doing this on used tires is pointless, the tire has already made a tread patch that may or may not be causing uneven wear.

[xjeeper]

When you add the tread depth they could be 34.2, tire specs are for the underlying carcass. I ran a shop and sold many tires, very few measured out to the claimed size, 35"s on oem wheels will work fine Ford released a proposed superduty offroad package to the press in 055-06 that was similar to the dodge powerwagon. It was running procomp 35" x terrains on standard 18" production wheels, using Ford snowplow coils to lift the front about 1". My 35" 12.5"x17 trailgrapplers are listed in the specs as having a 13.2" section width, so you need to go though the manufacturers specs and pic a narrower 12.5.

[Karls03]

The width number in a tire size refers to tread width, section width is always going to be wider than tread width. A 12.50 will mount on a factory 7 or 8 inch wheel, but at the rate that it increases wear on the center tread as psi goes up, I won't mount them on any less than a 10. I got better treadwear on my 285s on a 10 inch wheel.

[xjeeper]

Sorry to be contrary,but the width is section width. A 315 is a section width of 315 mm, or 31.5 cm. the next # is the aspect ratio; ie the sidewall hieght is 75% of the section width, and the last # is obviously the rim diameter. Mud tires almost always measure taller than their sister ATs ; ie BFG mt and at, of the same nominal size due to tread depth (muds are deeper), and the widths vari as well due to tread design, without changing the nominal size. As a 4x4 shop manager, I sold and fitted only ofroad tire and wheel packages often buying semiloads of tires for the store, and of all major brands, I had to know that a bfg would fit on a certain rim width, but not on a different rim width or backspace, and that a thornbird won't. I have actually measured tire after mounting in order to fix fitament problems on dozens of 4x4s,Wheel width and backspaceing are more important than tire size when fitting a wheel tire combo, and lift type is as important as height, for example; a 2" spring pack level kit will fit a 35" on a 9" rim 4.5" bs on a 99-04, but a 4" will not clear anything larger, because when compressed they both stuf to the same point. but a full spring replacement 2.5" will only clear a 305 because it can compress futher, the same aplies to a 2.5 hanger kit. Often a stock size tire will rub even lifted on an improper rim width or backspace. Sorry for the rant, but I read posts all the time that are anecdotal, but will not always transfer. I got 50 k out of 285/75/16s on stock wheels, and they still han another 15k miles to go, another mistake that people make is overinflating upsized tires, use the chalk test ton get it right, an E rated 35" can carry more weight than a stock 265 E rated tire at the same pressure. 2 different size tires of the same ply rating, @the same pressure supporting the same load will have a nearly identicle size contact patch (different shape), but with a larger tire you want a larger contact patch, so run a lower pressure to get a larger flatter contact patch. Taller tire sidewalls are more forgiving of improper PSI, so be especially careful determining your pressure for 20"s and22"s.

[Karls03]

Yeah, kinda dumbassed it on the section width/tread width number. Ehh...

However, my point being, keeping the rim closer to the tread width and realzing that the number on the tire is the recommended MAXIMUM pressure are two ways that I have learned to maximize tread life on my vehicles. Seems to be working, my 315 BFGs are on a 10" wheel at 45psi and the coin test shows real close depths across the tire.

[ledoux79]

Well thanks for the replies but I was actually asking if anyone thought a 34" tire was too small for a 4" lift appearance wise. Sorry if my question was misunderstood.
Anyway I actually bought a set of 2012 f250 20x8 rims and MT MTZ 35" tires.

[Karls03]

Originally Posted by ledoux79

Well thanks for the replies but I was actually asking if anyone thought a 34" tire was too small for a 4" lift appearance wise. Sorry if my question was misunderstood.
Anyway I actually bought a set of 2012 f250 20x8 rims and MT MTZ 35" tires.

If those wheels are going on to a 2004 or older, they will require a 2 inch spacer behind the wheels.

[ledoux79]

It's a 2006

[JasonY]

A 34" tire is what the stock trucks came with that had the 20" wheel option. A lift would be silly on such a small tire.

I have tires just short of 35" on my OE 20's, with zero lift.

Jason