Maybe cause of weight? Who knows. I Also have Mickey Thompson true size and weight. I did some research for a lot of tires via email to the manufacturers cause third party info I found was different on every page.

 

I put 34" MTRs w/k on my JKU Rubicon and ran them for 7000 miles the ride is a little harsher than I expected, even at 27 psi for even wear. I put on a set of 35X12.50R17 KM2s. They ride smoother and perform the same as MTRs. I had to increase tire size on my Superchip to get the speedo correct for the 35" KM2 tire. Therefore the 35"KM2 is slightly taller than the 34" MTR. They are both good tires and performance is comparable. I'm not sure if the Kevlar makes the MTR a tougher tire or not, as I have had no problems with either one. There is one big plus for the KM2. It rolls easier and my mpg went up by 10%. I didn't expect that, but I'll take it. I can feel the better performance on the road as well. I'll still have to wear out the MTRs, but I have another Jeep for that.

 

So you had an mtr 215? And then a km2 35?

 

No, they were 305/70R17 which GY says is 34.1". Their 35X12.50R17 has a 34.8" published size. In actual size, I would say that the 35" KM2 actual size is midway between GYs 34" and 35" tire. Bigger than the 34", but slightly (.35") smaller than the 35.

 

Wow, those 35's are light compared to mine...my STT's (325/6518) weigh in at 78 lbs!! I think my next set of 37s are pretty going to weigh the same as this set.

 

The 35" KM2 is actually heavier that the 35" MTR. This is due to the KM2 being D load rated and the MTR being C load rated.

If you are talking 37" the MTR is heavier.