View Full Version : 255 85 r16 tire size

06-07-2009, 10:35 PM
I was talking to tch2fly Mike on Wednesday at the meeting, he told me about a guy who was claiming that 255 85 16's were 35's. NFW, we both agreed, the math says 33.07 (=255 x .85 x .03937 x 2 +16) and I have always considered them to be 33's. Big 33's maybe, compared to 285's which are more like 32.8, but 33's, nonetheless

so after reading a lot of positive reviews about the Maxxis Bighorn, and considering my dislike for BFG MT, not wanting to chance the balancing & endure the hum of the Trxus, my aversion to the weight of the Toyo MT, plus the desire to try something different, my choice for the 255 85 16 to try on the Taco landed on the Maxxis. Anyway long story short today I find myself mid-mod on the Taco and I decide to roll one of those Maxxis up to the 80 to see how big it is...

I was surprised how tall it actually looks in comparison. The 80 has 315's, and yes they've been to Moab 3x, Rubicon once, all over Colorado.. actually I was suprised to look just now but I've got over 20,000 miles on them and IMO the tread still looks very deep. In fact I just ran out and poked around with a caliper, and measure the depth around .400". (the new Maxxis are more like .570")

So anyway, I'm tempted now to toss these skinny suckers on the 80, and see if I notice much RPM difference. Here are your pictures....

06-07-2009, 10:45 PM
And I'm kind of laughing right now, because these 33's were going to be my "emissions tires" and honestly I don't know that they'll be that much smaller. Maybe they'll have worn down another .25" or so before the 80's due on the rollers again. :lmao:

06-08-2009, 02:28 AM
Wow...The math "shouldn't" lie and http://www.4lo.com/calc/gearmetric.htm agrees with your math that a 255/85R16 is a 33.1" (x10") tire. A 315/75R16 is a 34.6" tire. The caveat here of course is how true to the size is a particular manufacturer's tire.

My only thought is that the Bighorn is unloaded and thus making it appear larger added to the Toyos being worn down, as little as they are. In the end though, those Bighorns sure look big :D

06-08-2009, 07:48 AM
I've got the Maxxis Bighorns in that size on my 40 (with the OME lift), and the fit is perfect imho. With about 6k miles on the tires, they measure almost exactly 33.0. That being said, I had a friend tell me his KM2's in that size measured close to 33.7 on his truck unloaded, which was a major factor in my decision to give the KM2's a shot on my Tacoma. Mine don't come close to 33.7, but mounted and installed on my truck they are about 33.2, and easily have over an inch on my 285 BFG's with 20k miles. It might be reasonable to call them "short 34's."

Lots of Tacoma guys run the Maxxis Bighorns off road, and the feedback has been really good for durability and wear.

06-08-2009, 09:02 AM
Lots of Tacoma guys run the Maxxis Bighorns off road, and the feedback has been really good for durability and wear.

Yeah that's what really pushed me towards the Bighorn Matt, I saw a lot of positive threads about it, even saw some of your posts on Expedition Portal.. :D the kicker for me was Kurt Williams running 3 consecutive sets- figure something must be right if he's willing to buy them again, twice.

06-10-2009, 09:55 AM
I had the same size/brand on my 80 before selling them to Matt. The were about 32.5" loaded on my 80 if I remember correctly...