Looking for 18" tire experiences (especially if on a P400 with TuffAnt alloys). Should I go with OEM sized 255/70 KO2, or give the upsized 265/70 Toyo's a shot?

I am switching to 18" wheels on my P400, and I am debating tire size/options. I prefer to stay as close to OEM size as possible (255/70), no lift, etc. I've read that 265/70 mostly works as well. It seems like there are basically 0 XL rated tires in 255/70 beyond the Wrangler, Duratrec, and Nitto Ridge Grappler. The problem with the latter is lack of three peak mountain snowflake certification.

In OEM size 255/70 are KO2: LT255/70R18, but these weigh 51 lb per tire compared to 39 lb for the Goodyear Wrangler. Going up to 265/70 unlocks Toyo Open Country AT III LT265/70R18 and Falken Wildpeak LT265/70R18, which weigh 50 lb and 59 lb, respectively.

 

I went with Nitto Terra Grapplers in 275/65. I ran into the same issue as you - wanting to get close to OEM size without lift or spacers (275/65 fit fine, they are the same diameter, just a little wider).

The Terra Grapplers are XL rated and snow rated, without going up to a much heavier truck tire. They have been good on moderate off road trails, and don't add any significant road noise. They are less aggressive than the Ridge Grapplers. As a heads up - when I ordered they made two different models under the same name and size with the only difference being one was snow rated and the other isn't. I think 216250 is the snow rated version.

 

I had not thought of 275/65 which is 10.8" width. Does the wider tire give you any issues rubbing at full lock?

I read here from @johnz330 that even 265/70 Toyo Open Country AT3 at 10.4" was giving them some rub at full lock.

I suppose these widths are nominal and vary from tire to tire. Unfortunately, the tire specs do not list width. Or perhaps this is because the TuffAnt wheels have a slightly different offset to OEM for those of us converting a P400 down.

 

I have had not issues with rubbing. I tested at access height with full lock and it isn't a problem. I'm using the stock 18" steel wheels, so you might want to confirm the offset, etc. The overall tire height is almost identical between stock and 275/65. The 265/70 option does create a larger diameter tire than 255/770 or 275/70, so that might account for the issue. Regardless of what tire you choose, if you can fit the 275/65/18Rs, it does open up more possibilities.

 

I wouldn't worry about rubbing with this size. They just barely touch at full lock and now that I've put on ~5000 miles you can't even tell looking at the wheel liners.
I narrowed my selection down to these two tires as well. Never had KO2s, but a lot of fans. I also found lots of reviews on other sites that said they didn't have good wet weather traction. That's why I sent with the Toyos.
The Toyos aren't much louder than the Wranglers and the ride is firmer but fine. The only issue I've had is that I've had them balanced 3 times and they're still not 100% smooth--only noticeable above 65 or so. Not sure if that's an issue with the tires or the limited amount of space for the wheel weights on the fronts between the wheel and brake calipers.

 

@BRW110 Do you have any pics of your truck? I'd love to see it with these tires on stock steelies.

Thanks
Matt

 

Awesome, thanks for the update! Balancing is concerning. My mechanic mentioned it takes some finesse to get wheel weights to fit, but it did not sound like it should be a real problem.

Other idea is to make sure they have been Roadforce balanced. I think most shops have switched to these, but I remember having wheel balance issues on a finicky BMW that was fixed by a road force balance.

 

This is in access height from when I first put them on last year. They aren’t the most aggressive AT tires, but I’ve been happy.

 

^^^^^ What a great looking truck! ^^^^^^^^
Very similar spec to what I ordered....

Thank you

Matt

 

The tyre size you choose should be based on the conditions you will encounter. If mud, slippery conditions or wintery roads are in your future then I would suggest you maintain the current width. The wider the tyre the greater the area of weight distribution.

If you must go larger, the 265/70/18 is a reasonable alternative and will only increase your rolling diameter by a half inch (your speedometer will read 1mph off at highway speed). However, I can't see any measurable benefits beyond aesthetics going larger than the factory spec size.

The KO2 is a safe and vetted choice and has been relied on by other OEM's. We don't use it for weight/noise/wear reasons, but it's an upgrade for the purposes of off-roading.

Hope this helps.