285/70/17 tire on a stock SR5 wheel which is only 7" wide is not the best idea and a lot tire shops won't mount the tires for you. It's been done many times with the TRD Pro wheels which are only 7" wide also but it does go against manufacturer recommendations. A lot of those people end up with wheel spacers to avoid rubbing. You will likely have to trim the inner edge of the front bumper and move the fender liner but that will be the case with any wheel you run.
285/70/17 tire on a stock SR5 wheel which is only 7" wide is not the best idea and a lot tire shops won't mount the tires for you. It's been done many times with the TRD Pro wheels which are only 7" wide also but it does go against manufacturer recommendations. A lot of those people end up with wheel spacers to avoid rubbing. You will likely have to trim the inner edge of the front bumper and move the fender liner but that will be the case with any wheel you run.
Like you said people put 285s on the Pro wheels all of the time and I haven't heard of a single issue. Sure manufacturers list 7" wheels in thier specs.
As far as spacers go thru will CAUSE you to rub more on the fender liners and mud flaps. The only extra clearence your gain from spacers would be tire to UCAs. I added 1 1/4" spacers the other day to my stock Pro and had to remove the mud flaps due to rubbing. Was pulling then off anyway to do the BMC for the 285s.
Hi, thanks for getting back to me! I am still VERY new at learning about tire stuff. So if I'm deadset on 285/70/17, what width wheel should I consider getting? I want to do this right and am willing to get new wheels if that's what I have to do. Additionally, let's go with the scenario I keep the stock SR5 wheel and move forward with 285/70/17: If I get the appropriate wheel spacers, will I still need to trim the inner edge of the front bumper?
Another scenario: if I pick 275/70/17 off road with stock SR5 wheels, would there potentially be rubbing/need for trimming? Or will that be a better fit? Again, I really appreciate your advice!
You can 100% bet on doing the fender liner mod which is nothing more than moving the plastic fender liner forward and trimming the inner lip off the front bumper. You will never even notice it was done as long as you take your time. For rims, 17x8 with 4.5" backspacing and 0 offset is pretty much the magic number. Lowest chance of rubbing and trimming other than the fender liner mod.
[MENTION=153213]2016 4Runner SR5[/MENTION] I just realized a better question might be: "I want to run 285/70/17. What do I need to change on my stock SR5 to make that happen?"Depending on that answer, if it's a big expense and lots of things to change, "would running 275/70/17 be 'easier' to do, in terms of less things to change and cheaper?"
I text the same way - many, many double texts instead of 1 long, thought-out text. One day I'll learn!
[MENTION=153213]2016 4Runner SR5[/MENTION] I just realized a better question might be: "I want to run 285/70/17. What do I need to change on my stock SR5 to make that happen?"Depending on that answer, if it's a big expense and lots of things to change, "would running 275/70/17 be 'easier' to do, in terms of less things to change and cheaper?"
I text the same way - many, many double texts instead of 1 long, thought-out text. One day I'll learn!
It's all about your wheel choice and intended use. This is my 2016 SR5 with a 1.5" lift front and rear. Wheels are 17x8 with 4.5" backspacing and 0 offset. Tires are 295/70/17 Nitto Ridge Grapplers. All I did is the fender liner mod. No body mount chop needed, no rubbing at all on the street. If I was to take it off road and flex it, I have no doubt I would have rubbing. For a street driven rig, you're all good to go.
I ran 275/70-17 KO2s on stock SR5 wheels. I had no issues at all, no trimming and no rub. Caveat to that statement is that BFGoodrich tires are known to run smaller, and I only ran those tires with my stock suspension for one week before I got my first lift, so I didn’t have a chance to wheel with them. But on the street they were fine.

Cleaned her up and tried out some bumper accessories.
C4, if you're watching, I'd love to see one of your bumpers that can accommodate two of these...
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Had to replace my hvac blower fan. SO MUCH QUIETER!