285/70 vs. 285/75 tires

Getting ready to build out our 2021 TRD Off Road and trying to decide between 285/70/17 and 285/75/17 Nitto Ridge Grapplers with the C sidewall rating.
There is aprox 1" of difference in height on these tires. I know once the tire is mounted and then has the load of the vehicle on it I will lose about 1" in height so I am leaning towards the 285/75 flavor. Being a noob to the 4Runner platform, am I going to regret this decision? I am planning on running the Eibach Pro stage 2 lift which has coil overs.

 

your wheel offset will also play a factor. I had to do more trimming to the fender liner when I switched from 285/70/17 to 285/75/17

 

Right now will be running those gawd awful hideous TRD Off Road rims if that matters. Would love some TRD Pro rims but not in the cards yet. I'm not oppsed to trim liners. I come from the Jeep world so taking an axe to the vehicle doesn't scare me lol.

 

I would not recommend 34's (285/75/17) without a regear. I have 285/70’s and 295/70's, and the 295's are really pushing it. I have to drive in S4 to avoid constant downshifting.

The 1" height difference is over the full diameter, so you're only losing 1/2" of ride height.

Also, 285/70's can generally fit with a good alignment and maybe a little plastic trimming. 285/75's almost guarantee that a BMC will be required.

As @blksubykid mentioned, wheel offset will play a big role.

 

I actually prefer the OR wheels over the PRO wheels, but maybe that's just because EVERYONE has the PRO wheels.

I'd recommend aftermarket wheels over the PRO wheels, as most manufacturers recommend a wider wheel for 285's.

 

That is also a good point. I definitely felt the difference between the two tires and I am re-geared to 4.56.

I think his alignment, specifically caster, and wheel offset will determine if he will need a BMC or not with 285/70/17s. Some people need it, others don't but I did mine as a precaution prior to getting larger tires. I would do it especially if you plan to continue to mod and wheel the truck. It's not expensive and most shop can do it...unless you can weld it yourself.

Flattening the pinch welds might be needed with 285/75/17s, dependent on manufacturer as sizing can range, but I noticed I lost some paint on mine after our Colorado/Utah trip. I'll be cutting and flattening mine in the near future.

 

I havent seen much on 285/75. How much tire variety is out there in this size?

 

16 tires are listed for me from America's Tire
https://www.americastire.com/fitmentresult/tires/size/285-75-17?storeCode=1734

I personally run Yoko Geolandar MTs (got 5 for a steal)

 

I am new to increasing tire size, right now I have a TRD Pro with the standard 265/70/R15 and I want to get the 285/70/R15 K02s. If I get the latter, will I have to do any body modifications? I am not experienced in body modifications, and every tire shop I talk to has no interest in helping.

 

There's a decent selection. I was looking at the Yokohamas in that size before I chose the 295's.

 

No tire shop is going to help you on this endeavor. The forum and youtube us your friend. Are you planning on lifting the 4Runner? If not it sounds like you will need to do significant modification but if you do lift you will need minimal. Also, from personal experience, I recommend you look at other tires. IMO the KO2s suck in the rain and there are so many other options out there.