Which 40 is good these days?

Actually, I think those are Michelin XL. You are right that they are a pretty heavy tire. They work really well on a unimog, although they don't wear great with those big blocks. I'd guess that size in the photo is likely 12.5R20, which are about 39".
 

RockChucker

Well-Known Member
Location
Highland
I had a set of 40” razrs on my tj a few years back. I wasn’t a huge fan. I thought the carcass was too flexible. At low enough pressures that they seemed to hook up well (8-9 psi) the sidewalls folded over while turning or sidehilling and things felt generally unstable and it didn’t want to hold a line super well. I wasn’t impressed how well they hooked up compared to my mtrs or current km3s at 12-13 psi where the tire structure was more stable. My tj weighs about 4800 lbs trail ready, so not light but not extremely heavy either. Maybe in the 20” wheel flavor they would be better. I only have personal experience with the 40s though. I sold them after approx 1000 miles total on them with a couple trips to moab. YMMV
 

Tonkaman

Well-Known Member
Location
West Jordan
I had a set of 40” razrs on my tj a few years back. I wasn’t a huge fan. I thought the carcass was too flexible. At low enough pressures that they seemed to hook up well (8-9 psi) the sidewalls folded over while turning or sidehilling and things felt generally unstable and it didn’t want to hold a line super well. I wasn’t impressed how well they hooked up compared to my mtrs or current km3s at 12-13 psi where the tire structure was more stable. My tj weighs about 4800 lbs trail ready, so not light but not extremely heavy either. Maybe in the 20” wheel flavor they would be better. I only have personal experience with the 40s though. I sold them after approx 1000 miles total on them with a couple trips to moab. YMMV
Good to know. My truck is obviously way heavier than the TJ so maybe not a good choice at that weight.
 

rholbrook

Well-Known Member
Location
Kaysville, Ut
I thought you changed your ways since the big ole Chevy. I have pissed away a lot of money on tires and wheels over the years. They wear out fast, especially with diesel torque. They wear out drive train parts faster, the ride sucks, they are noisy and most importantly, everyone thinks you have a small weiner. This is going to be one big ass truck. You will need an elevator to get the bikes in the back. Now..can't wait to see it all done.
 

Hickey

Burn-barrel enthusiast
Supporting Member
Good to know. My truck is obviously way heavier than the TJ so maybe not a good choice at that weight.
I think the weight of a heavier truck would actually help, as you would be running higher pressures offroad than a JK or TJ would. You'd likely be in the 14-18 psi range which would stiffen that carcass up a bunch.

I have them on 8 lug chev/Dodge pattern wheels right now if you want to drive out to my house and mount one on your truck to see what that pressure looks like. They are 37" tires.
 

Tonkaman

Well-Known Member
Location
West Jordan
I thought you changed your ways since the big ole Chevy. I have pissed away a lot of money on tires and wheels over the years. They wear out fast, especially with diesel torque. They wear out drive train parts faster, the ride sucks, they are noisy and most importantly, everyone thinks you have a small weiner. This is going to be one big ass truck. You will need an elevator to get the bikes in the back. Now..can't wait to see it all done.
I figure if advertise my tiny wiener then I won’t have to turn away so many babes :cool:

I’m hoping this truck build comes across as a capable off-roader with the capacity to haul around a family, not just some mall crawlin bro mobile. The lift will still be limited at 3” and the tires will be there to help transition that big body across obstacles smoother.
 

Tonkaman

Well-Known Member
Location
West Jordan
I think the weight of a heavier truck would actually help, as you would be running higher pressures offroad than a JK or TJ would. You'd likely be in the 14-18 psi range which would stiffen that carcass up a bunch.

I have them on 8 lug chev/Dodge pattern wheels right now if you want to drive out to my house and mount one on your truck to see what that pressure looks like. They are 37" tires.
Your right. I was thinking about that the wrong way. I’m not quite ready to pull the trigger but maybe in a couple weeks I’ll take you up on that. Thanks!
 

Hickey

Burn-barrel enthusiast
Supporting Member
Your right. I was thinking about that the wrong way. I’m not quite ready to pull the trigger but maybe in a couple weeks I’ll take you up on that. Thanks!
They're E rated tires, so you really gotta get the psi down low with the lighter rigs. This was at 8 psi:

86341490-1907-4649-B66D-66E67E7E842F.jpeg
4447BB6C-B965-4D98-BF68-3AADF5F3B0FD.jpeg
 

jeeper

Currently without Jeep
Location
So Jo, Ut
I thought you changed your ways since the big ole Chevy. I have pissed away a lot of money on tires and wheels over the years. They wear out fast, especially with diesel torque. They wear out drive train parts faster, the ride sucks, they are noisy and most importantly, everyone thinks you have a small weiner. This is going to be one big ass truck. You will need an elevator to get the bikes in the back. Now..can't wait to see it all done.

I used to mock @ricsrx when I was in high school because he had the most gorgeous CCLB ford, but he kept it on stock lift and tires.
I couldn't believe he was such an old man back then.

Now I refuse to lift my CCLB, and I keep stock tires on it. :rofl: :rofl:

I should get some stickers made that say 'Stockest is Hottest'
 

Cody

Random Quote Generator
Supporting Member
Location
East Stabbington
Changing rim size never even crossed my mind. That being said I don’t see that tire size in 18, but the 40’s are E rated on 20s

Pretty sure I should stay with 17’s though
Ya that must have been what I was seeing. But I guess less sidewall should equal more load rating. Makes sense in my head anyway
 
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