New Toyo Open Country A/T III tire

The LT285/75R17 comes in both a C and an E load rating. They measure the exact same and the E is only 1lb heavier (59 vs 60). Other than the increased load capability, any reason to consider the E rated tire? I'm under the impression the E will have worse ride quality than the C. True or nah?

That tire size is an odd one. It's a true 34 but a bit narrower than a 285 which is something I'm looking for. I have to do some measuring but I think this may be the max tire size you can get on before really having to get out the Sawzall.

 

My response will not help but. I contacted Toyo and asked them why was there no "C" load rating in 265/75/16 and there response was that testers did not feel a difference in ride quality compared to the "E". So asked why is there both "C" and "E" load ratings on some sizes in 17" diameter. Received no response for that question. My only hope would be that the "C" load rating version would air down better. But I have no idea if that would be true.

 

I think you may still need that sawzall with the 285/75r17! Toyo's run tall. Keep us informed of you go for it, would love feedback on that size.

 

It's a 33.9" actual size and the BFG KO2 is a 33.25 in the 34/10.5/17 size. I've been running the KO2s for years without issue. The only thing I'm worried about is the extra width. I'd be going from 10.5 to a 11.3 in width. Hard to tell if that's just contact patch difference or if the actual sidewall is wider too.

After my experience with tire sizes on my RS3 I've learned not to trust manufacturers numbers. An OEM Pirelli PZero 255/30/19 is an inch narrower (contact patch) than a 245/35/19 Michelin Pilot Sport 4S. That's not a typo.

 

I believe the E rated tires may have a deeper tread too.

 

Toyo list them as both having 16.5/32"

 

Listed width or section width is sidewall-to-sidewall. Or as Toyo states- overall width.

 

I see 13.3 for SL and 16.3 for the LT on the Toyo page for 265/75 16 .

 

That may be but he was referencing a 285/75/17 "C" and "E" load.

 

That's the same for the KO2. It's 10.5" on the nose (verified with a caliper about 5 minutes ago). Contact patch is about 9 or so depending on which tread block is being measured because they are staggered.

Indeed I was.

 

I just wish the sidewall on this tire was a bit more aggressive looking

 

Just pulled the trigger on a set of the LT285 /75 R17 C-load range tires.
https://www.discounttire.com/buy-tires/toyo-tire-open-country-a-t-iii/p/88423

My Fox 2.5 shocks are on a pilgrimage to AccuTune for a revalve (going softer) and while they were out I figured I'd check the clearance. I have 60k miles on these BFG KO2 34/10.5/17 tires and it's time to replace them. They're about an inch smaller than they were when new so assume the tire being measured is about a 32.5" tire. Pictures are at full stuff with the bumpstop touching the LCA using a jack to hold it up. This is with my existing alignment settings. As you can see from the pictures, there's more room up by the bumper than at the mud flap. A keen eye will see that I already have a wear spot in the mudflap from half lock steering when the KO2s were new.

Anyway, I played with the caster settings and was able to draw the wheel forward about 1/2" which placed it right in the middle. I don't think I'll be able to keep the mudflaps but it's been a good 11 years so I won't complain too much. I think I can use a heat gun to eek a bit more room out of the fender liners if needed but other than that, it should be pretty close to good. I won't know for sure till I get the new tires mounted up. Hoping to do that tomorrow or maybe Sunday. Keep in mind, this is with the wheel as far up in the travel range as it could possibly go. Maybe you'd get a wee bit more if you really put a ton of pressure on the bumpstop and deformed it....but at that point, "Here be dragons...."

Including obligatory hover truck photo since it's relevant...

 

Ok, good news bad news....Regarding the 285/75/17 C on a OEM Sport wheel, good news is I don't think there are any fender clearances at the top of the tire. Bad news is, there's some clearance issues at both the front and the back when turning lock to lock at full stuff. I can move the LCAs so it pushes the wheel forward in the wheel well which helps a lot. With a little trimming of the flares and molding of the fender liners, we should be good. Passenger side required less than the driver's side. It will still be VERY close. If you have tired old OEM bushings in your LCAs they will exhibit a fair amount of deflection (wiggling) and close the gap you opened by trimming when under stress. I have Whiteline Poly bushings in the OEM LCAs that are pretty stiff so I am thinking I should be pretty much ok.

However, one thing I'm seeing is that with the LCAs positioned at max caster to move the wheel forward in the wheel well, the camber starts to go positive...which is not good. I'm pretty sure I'm going to need adjustable camber UCAs to get that part right. Other than that, it's looking good. Shocks don't come back for about a week so I've got time to work on it.

PS: Finally had to lose the mud flaps...made it almost 12 years. Pour one out for my dudes...

 

Thanks for the info!

Although, doesn't the tire scrape the inside of the wheelwell when at full compression?

 

Not with the wheel straight. At full stuff, when you start turning lock to lock you'll get rubbing on the fender liners (other places too). However, it would appear that using the heat gun to re-mold those areas is quite effective. It becomes very pliable and somewhat stretchy. Key is to hold it in your desired shape till it cools. Then it will stay that way.

 

Anyone with a good psi for a 31 inch tire and e rated? Running 40 and seem to have a full contact patch... Need to do a chalk test when I find some chalk...

 

What weight-adding mods do you have on the truck? Anything substantial? 40psi seems high to me. That's higher than stock and the OEM rubber is C load range, right? I'd imagine it will ride like hell on 40 but I'm FAR from a tire expert.

 

This will give you the "proper" tire pressure for a different size or load rating than stock based on the manufacturer's recommended pressure.

I haven't always followed it exactly, but it is a good starting point.

 

Awesome, thanks. I use that site a lot. Just found another use.

 

Doesn't ride bad though. But yeah, seems high although looks to be a solid contact patch and its with an E-rated. Will use the calculator mentioned below.