Tire width? 285/70 vs 285/75

[cilles]

Opinions on Tire width? 285/70 vs 285/75
I know I'll likely need the Westcott lift before I can even run 285's without rubbing, assuming I do that.
Also do I need offset to run /75? do I need it of I do /70 (both 285/)?
I also see that /70's are lighter which is always good.

 

[serbiansizzle]

I think this entirely depends on what wheels you’re talking about. If you’re keeping a stock wheels it’s very different then if you went with something like a zero offset aftermarket wheel. A lot of people are running 285/70/17 with lower offset wheels without any lift or rubbing issues. When you get into some zero offset tires, you have to be a bit more careful and probably have to look at something like a lift.

There is a wheel and tire section here we can take a look at what some people are running with different set ups from stock all the way to Wescott design lifts.

And lastly, depending on your usage of the truck, we will definitely play a factor. Once you get into the LT rated tires, you’re gonna be adding some pretty significant rotational mass that could impact the ride quality as well as the overall fuel consumption of the vehicle.

 

[munkeeboi]

Seems in your questioning that there is some confusion in tire sizing nomenclature. I'm assuming this is for an 18" rim. The width you are asking about are the same for both, 285 mm. The difference between /70 or /75 (the aspect ratio) will be in tire diameter. /70 will usually be lighter than a /75 in the same tire because it's a smaller tire, but tire weights will vary based on rating and manufacturer

Offset would determine fitment and any rubbing issues. The closer you are to stock offset, the less fitment and clearance issues. The lower you go, the more you introduce potential for rubbing. A lift will not help rubbing if your offset is low

 

[Bluegill]

285/70/18 = 11.23" wide and 33.72" tall

285/75/18 = 11.23" wide and 34.84" tall

Stock Lexus GX550 Overtrail = 265/70/18 = 10.7" wide and 32.64" tall

Note that these are the exact calcs and the actual dimensions vary by manufacturer, but they should be close.

Like munkeeboi mentioned, the wheel offset is just as important as far as rubbing issues are concerned. The stock Overtrail wheels are +50mm offset. Most of us that go up to 35s with the Westcott kit are running +35mm offset.

Are you hoping to keep your stock Overtrail wheels? I'd think the Westcott kit would accommodate 285/70 or 285/75 with stock 18" Overtrail wheels but I am not sure.

 

[cilles]

Yeah my bad on the numbers. Thanks for info. I’ll check the tire section here. Didn’t know there was one. And I already have LT tires on GX 550 OT+