285/75/17 vs 285/70/17?

[Jetboy]

Quick hijack. But what are you running for rear bumper protection? Custom?

Yeah. It's a custom one I built a few years ago. I mostly did it as a one-trip prototype. But it worked pretty well and protects from the parking lot dents and dings, so I've kept it on.

I pulled it last night to give a fresh coat of paint and bend it back into shape a little bit so I took some pictures. Also on Page 2 you can see the rear bumper @WFO built for his that has a lot higher clearance than mine. I didn't want to cut up my OEM bumper. Looking back I'd probably just cut the OEM bumper and build one more like his setup with higher clearance. But this one works for what I tend to do with it.

Rubicon Trip Report - AND Minimalist Rear Bumper Protection (Bolt On)

 

[4boer2]

FWIW - I have 285/75/17 Cooper AT3s.

Body mount chop was required. Not really even close to fitting without. Lift makes no difference in tire fit in the front, so height doesn't matter. But I have about 2.5" lift (adjustable Fox suspension). Alignment and UCA matter. I have JBA UCAs and alignment set to about 4*. They still rub on the front bumper lip at full lock in reverse a little bit. Otherwise. After a mild BMC there's plenty of clearance at the body mount/fender area.

What stood out most in the Cooper version as compared to a Toyo AT2 was that the 75 was both taller but also significantly narrower tread. They're even narrower than my street tire set, which are 275/65/20 - by almost an inch at the tread.

Mine are on stock wheels. I have some custom 1" spacers that I use. I machined the back side of my OEM wheels for space for the studs. This is getting into a bit more custom machining that you should not DIY unless you have some experience machining aluminum.

This looks like a great option. I'm happy to see you can keep the stock bumper, but maybe the pre-facelift models are different. Did you re-gear? Do you think you need to if it's not a mud tire?

 

[Jetboy]

This looks like a great option. I'm happy to see you can keep the stock bumper, but maybe the pre-facelift models are different. Did you re-gear? Do you think you need to if it's not a mud tire?

I just did a re-gear in the last week or so. Overall though I'd say no. You do not need to re-gear if you're not hauling a lot of weight. It's perfectly fine off road. On the highway it does struggle to hold 5th gear most of the time at higher speeds. So far I'm mixed on the re-gear. I don't have enough time with the new gears to give a full evaluation. I have some gear whine that I'm not super happy about, so I'm still up in the air on the re-gear as of today.

If there were a gear set in the 4.10 range - that's what I'd want.

 

[Hydguy]

Metric tire sizes are stupid, as this thread, and every other tire thread, proves.

 

[4boer2]

I just did a re-gear in the last week or so. Overall though I'd say no. You do not need to re-gear if you're not hauling a lot of weight. It's perfectly fine off road. On the highway it does struggle to hold 5th gear most of the time at higher speeds. So far I'm mixed on the re-gear. I don't have enough time with the new gears to give a full evaluation. I have some gear whine that I'm not super happy about, so I'm still up in the air on the re-gear as of today.

If there were a gear set in the 4.10 range - that's what I'd want.

Hmm.. factory bump stops both front and rear you said? I'm trying to put together a list of the things I would absolutely need to do. So far it's just UCAs and the BMC plus some trimming, but I'm not sure it's completely worth it. I think I could spend money a bit wiser at the moment.

 

[halflife78]

Can someone post that entire tire chart from the first post? I saw that the other say and was looking for it.

 

[EddieV4runnin]

285/70 BFG KO2 on 17x7 (~50% tread) vs 285/75 BFG KO2 on 17x8.5

BFG and their whack sizing. spec'd to be taller, but looks wider / larger tread blocks. haven't tried to measure anything yet, I'll update over the weekend

edit:
measured both wheel/tire combos off the vehicle
285/70: 31.5" (with about 0.5" tread worn)
285/75: 33"

i thought the 75's were wider but both measured 9" across the tread. i think its an optical illusion due to a 1.5" wider wheel (better suited for 285) and the tread blocks themselves being physically bigger to accommodate the larger circumference

More pictures on 4Runner?

 

[codyHTX]

pics on the car Cody?

More pictures on 4Runner?

knee surgery has kept me from getting out and doing much, I'll get some pics possibly over the weekend

This is the exact combo I am looking to move to (SCS and 285/75/17 ko2). Hows the ride and mpg delta from the smaller ko2's?

Thanks!

haven't put enough miles to really say, and i honestly pay no attention to mpg, but the change from 285/70 to 285/75 didn't feel as noticeable or dramatic as going form 265/70 to 285/70. from stop you don't get up and moving too quickly, but even that can be helped with more skinny peddle. it readily wants to down shift to 4th climbing at hwy speed of course, but for some reason the shifting has felt smoother and more consistent from 4th back into 5th, where i would previously see it want to hold 4th or would clutch, rev, and kind of drop into 5th. appearance-wise, i very much like the SCS 8.5"x-10mm stance and the tall-but-not-too-wide 285/75

 

[Sparman]

285/70 BFG KO2 on 17x7 (~50% tread) vs 285/75 BFG KO2 on 17x8.5

i thought the 75's were wider but both measured 9" across the tread. i think its an optical illusion due to a 1.5" wider wheel (better suited for 285) and the tread blocks themselves being physically bigger to accommodate the larger circumference

To provide some clarification:

The "285" spec is the width, so you would expect both to be the same.

The "70" or "75" is the sidewall height relative to the width - so 70 would be 70% of width in height vs 75%.

 

[EddieV4runnin]

knee surgery has kept me from getting out and doing much, I'll get some pics possibly over the weekend



haven't put enough miles to really say, and i honestly pay no attention to mpg, but the change from 285/70 to 285/75 didn't feel as noticeable or dramatic as going form 265/70 to 285/70. from stop you don't get up and moving too quickly, but even that can be helped with more skinny peddle. it readily wants to down shift to 4th climbing at hwy speed of course, but for some reason the shifting has felt smoother and more consistent from 4th back into 5th, where i would previously see it want to hold 4th or would clutch, rev, and kind of drop into 5th. appearance-wise, i very much like the SCS 8.5"x-10mm stance and the tall-but-not-too-wide 285/75

Thank you, get well soon brother.

 

[DaveSmith]

Any updates on 285/75-R17s on 5th Gen 4 Runners?

Does anyone have any updates and real work experience with running 285/75-R17s on a 5th Gen 4 Runner. (Not the smaller 285/70's)

Would you do it again? Do you have any regrets? I'm surprised that the 285/75 isn't more popular on the 4 Runner.

This summer I'm going to try Cooper ST Maxx 285/75-R17s with some SCS Ray 10s 17x9, -38mm offset, 3.5 backspace. This offset/backspacing should be equivalent to using a 1.25" spacer on stock wheels.

Platform: 2019 5th Gen Off Road 4-Runner, Icon Stage 7 Suspension, SPC Performance UCAs, CBI front and back bumpers, body mount chop, pinch-weld folded over, 4.88 Nitro re gear, Harrop E locker up front.

 

[comtn4x4]

Does anyone have any updates and real work experience with running 285/75-R17s on a 5th Gen 4 Runner. (Not the smaller 285/70's)

Would you do it again? Do you have any regrets? I'm surprised that the 285/75 isn't more popular on the 4 Runner.

This summer I'm going to try Cooper ST Maxx 285/75-R17s with some SCS Ray 10s 17x9, -38mm offset, 3.5 backspace. This offset/backspacing should be equivalent to using a 1.25" spacer on stock wheels.

Platform: 2019 5th Gen Off Road 4-Runner, Icon Stage 7 Suspension, SPC Performance UCAs, CBI front and back bumpers, body mount chop, pinch-weld folded over, 4.88 Nitro re gear, Harrop E locker up front.

I've run 285/75's for about 4 years and I run those exact tires now. I like the tire size in general and have been on the ST Maxx's now for about 6000 miles. They are an excellent preforming tire that I can definitely recommend although they aren't light and are more aggressive than the average AT. It's tall for a 285/75 @ 34.1" mounted on the rig. They do follow the road grooving some but not terribly so. Noise isn't bad at all. I think with your wheels you might have some rubbing even with the pinch welds hammered. I have BMC and pinch welds hammered also and lots of trimming in the back fender well. Caster approaching 5*. My wheels have much less offset than yours, +1 mm 5" backspacing. I ran 305/70's at one point without a problem

 

[ultraxr]

I’m going to switching out my P rated Falken Wild Peaks ATs in 285/70/17 for some Yokohama Geolandar G003 MTs in 285/75/17 soon. I’ll admit I got the Falkens not expecting to go off roading much. But once I did, the bug got me good. I’ll share once I get them mounted

 

[jmswts]

I debated back and forth between 285/75 and 285/70, after seeing [MENTION=127657]codyHTX[/MENTION] 's comparison post I wanted to go 285/75 KO2 but they were out of stock for a few months so I went with Ridge Grappler's in C which are a bigger tire than the KO2's but I measured it out with my method 701- 17x8.5 - 0 offset and just took the risk. So glad I did.

I've got about 2k miles on them so far, lots of freeway/around town and then last week a trip to Death Valley; Titus canyon and Racetrack Playa @ 17psi.

So far I'm loving them. Maybe slightly quieter than the 275/70.17 K02's I had previously. For weight I can tell there is a difference but the truck is already slow and I don't have a lot of weight so I personally find it negligible and worth it so far. On a 1000mi freeway tip from Southern CA to Northern CA I tracked my file and got about 1mpg-ish less than before sizing up.

For fitment; I've got a about a 2/2 lift, I had a BMC done and had a bit of plastic trimmed from the front fender as well as the caps below where the mudguards were. I'm still rubbing a tiny bit on rear plastic where it comes down and meets the pinch weld but only when pulling into steeper entry ways around town, I didn't rub at all in DV but those trails have very little in terms of articulation.

 

[codyHTX]

some 285/75 on 17x8.5 -10mm Ray10s pics per [MENTION=157739]Metal Head[/MENTION] request and a flex test post:

https://www.toyota-4runner.org/3641850-post99.html

 

[2aadvocate]

Pinch Welds

some 285/75 on 17x8.5 -10mm Ray10s pics per [MENTION=157739]Metal Head[/MENTION] request and a flex test post:

https://www.toyota-4runner.org/3641850-post99.html

Did you need to cut and fold your pinch welds for those flex posts?

 

[comtn4x4]

Did you need to cut and fold your pinch welds for those flex posts?

I'd plan on it

 

[mrblah]

did someone say flex test?

Did you need to cut and fold your pinch welds for those flex posts?

UM...yeah...lol.

Front end at full flex, will hit the upper inner fender and pinch weld (if flexed and wheel turned). Will either require extended bump stops or alot of hammering to inner upper fender, and pinch weld mods and BMC. I choose extended bump stops. Seriously, its pretty easy fixes.

Rear tires, no problem with extended bumps....

see pics for reference:

 

[CrawlCulture]

Really like the 285/75/17 size. These are trail graps on 17x8.5 (0 offset but spidertrax 1.25” spacers) methods. I used 3/4” bump stop spacers (I used timbren bumps) in the front and trimmed a little but it tucks nice and doesn’t rub so I’m happy.

 

[Fortuner]

Really like the 285/75/17 size. These are trail graps on 17x8.5 (0 offset but spidertrax 1.25” spacers) methods. I used 3/4” bump stop spacers (I used timbren bumps) in the front and trimmed a little but it tucks nice and doesn’t rub so I’m happy.

Hey, where did you source the front ¾" bump stop spacers? Great setup on your rig btw.