Max tire size without regearing?

What is the max tire size we can get away with before regearing?

 

That's going to depend on how you drive, to an extent. I'm on 33's and totally fine. Others aren't even satisfied with acceleration on stock tires.

Any increase in size will increase wear. I will probably regear if i go any bigger than 33".

 

For sure, as Thatbassguy says, we all have different opinions about performance. It’s such a personal choice. But ask yourself this: if you had tested your 4 Runner and the front tires rubbed, and you had to remove mud flaps and melt inner fenders to fix it, and it accelerated like it was pulling a heavy trailer, would you have bought it like that?
Probably the limit you ask about is one size up, but I get it, 285s look cool. Maybe 295s are even cooler. So, I know that if I planned on doing any trailering or carrying any loads, along with 285s, I’d regear for sure. Not only would I get better performance, but the engine and transmission would be a lot happier as well. If you want to see this in action, there’s a cool you tube video on the Tacoma Beast channel where an overland Tacoma regeared to 5.29 drag races a stock Tacoma. I think the stock Tacoma wins. Watch it, and you’ll get the idea. If he hadn’t regeared a little kid on a tricycle probably would beat him across the line.

 

That and if you pull stuff, I imagine. Some thought-provoking ideas here:

https://trail4runner.com/2019/07/18/regearing-4-56-gears-5th-gen-4runner-review/

 

@Shnook718 it will also depend on how you're using the 4runner.

If you plan on towing heavy and often, you're going to put more strain on the drivetrain than someone who just throws a few things in the back and goes camping.

What are your plans for the 4runner?


Another thing I should mention is that I drive in S4 a lot, as opposed to overdrive. Keeping it out of overdrive in the hills helps a lot. Even on stock size tires, it would downshift a lot on an incline.

 

According to going from the stock 265/70R17 to 285/70R17 makes your stock 3.73:1 gear ratio feel like it's actually 3.6:1.

If you scroll down that same page to the chart and if you blur your eyes a bit (read between the lines), you can see that where the 265/70R17 tires (31.6" in diameter) intersect with the 3.73 gear ratio. Now make that same intersection using the 285/70R17 (32.7" in diameter) tire with the 3.73 gear ratio. For both of these, the intersection is in the blue band, meaning "Highway, Good Fuel Economy".

If "Best Overall Performance" (green band) is your goal, you'd drop in 4.11 gears for stock tires up to 33" tires, anything beyond 33" tires and you should be looking at 4.56 or higher gears.

 

Yeah the thing is that not many of us know how 3.6 “feels”. That’s what the OP is asking. On a heavy vehicle powered by a 4 litre gas engine and auto trans its marginal - but that’s a subjective opinion for sure. Just like women wearing high heels for looks guys put big tires on Toyota’s for looks too - I get it. I’ve done it too, but I try not to make the same mistake twice. But with regearing I’d do it, if I needed it.

 

As @xyzzy pointed out, the actual size difference from 265/70/17 to 285/70/17 is very small. If you look at revolutions per mile, it's only about a 3.5% difference. I used Toyo Open Country AT3' for reference here, but the size difference should be similar between manufacturers.

 

I have 295’s (true 33” tire), and for me it drives well. I’ve hauled about 1000lbs and it does fine. Decent acceleration, and overall is driveable. If I were to row frequently though, I would absolutely regear no question. Going up steep hills it does okay (can cruise up a very steep hill on the highway at 65mph at about 3k RPMS), but if I were to be towing anything I would definitely be overloading the transmission with stock gears and the 295’s. My two cents, and of course opinions will vary. Another thing to consider is MPG. I’ve been happy with my rig, I’m around 17MPG with mixed city and highway driving. If MPG is a big factor for you I wouldn’t go past 275’s.

 

Good to know, I've got 295 Geolandar MTs sitting in my garage waiting for my lift to get here!

 

You’ll love how they look, and start to catch the bug and think they look small and want to go 35’s be sure to post once everything is installed

 

Great article.

 

Yup, that covers it perfectly, for sure.