37x12.5x17 BFG AT ko2 Mounted

[Nay]

It's been a long time since I've been active on Mud - kids' ages and life and all that stuff, but hoping to wheel more this summer. I've been wearing down a set of 37" Trxus MT's that could no longer be considered remotely round, and I just couldn't bring myself to get another pair since much of my use is skiing miles. Was not easy to let go of that snow performance...but it was time to get modern.

I pulled the trigger on AT ko2's after reading some very good reports on winter performance. They are paired with MB (Discount Tire's in house brand) TKO rims in a 8.5" width with a -6mm offset, keeping back spacing at the factory 4.5". I retained the 1" wheel adapters with the new setup.

A few impressions. It's a great looking tire, and ridiculously civilized. The Trxus were beat, but I feel like I am on 31" highway tires. Fuel economy is up about 1 mpg. I am getting over 14 mpg on ski trips, which are all highway miles.

Deep snow performance seems pretty good, but they did pack up and slide in the storm we just had when it was pure, smooth, nearly all water slush as heavy rain transitioned to heavy snow. That's a tough condition for any tire biased to road use, but the reduction in lug spacing and reducing lateral traction showed up. Once the snow firmed a bit all was right again. I need a lot more winter miles to get a better feel in all conditions.

Anyway, it's all about the pics...

 

[Taildragon]

Welcome back Nay, always enjoyed reading your writing

 

[Nay]

I appreciate that - it's been too long...

 

[Cruiserdrew]

Cool. I just bought the same tires and will be real world testing next week. I wanted quieter than Duratracs and on other trucks the BFG ATs seem to last forever.

 

[LFD2037]

Welcome back Nay, always enjoyed reading your writing

x2. I don't know you but I've read a lot of your informative input & wondered where you went. Stick around awhile!

 

[DudeAbides]

Man, I really wanted to get those in the 37. Ended dropping down from 37" military baja's to the 315 ko2. Great tire.

 

[cc93cruiser]

Welcome back Nay. Always nice seeing the veteran mudders drop a post or two...

 

[MTKID]

How many miles did you end up getting out of the Trxus? My 80 has been demoted to just trail rig & am planning on them sometime this summer.

 

[Nay]

Thanks for the welcome backs...

About 35K. I'd definitely still be running Trxus on a trail rig, but I actually put about 12K miles a year on it these days - she's at 209K now.

The Trxus were a bit more expensive than I would have thought, especially for now seeing decent highway miles - it was over $60/tire more than the BFG so that paid quite a bit towards new rims while finally going to 17" rims to open up future tire choice.

I did groove the outer lugs and sipe the inners with a heated knife once the factory siping was worn through. You can see the grooving in the pic above. That breathed major new life into them, probably got 15K more miles where I thought that the traction was still 100%.

 

[MTKID]

Thank you very much for the thorough response!

 

[wearsabrowncoat]

The AT KO2's are priced very aggressively right now. The cost less than the old KOs. Costco also has a $70 rebate going on a set of 4. Only problem is they won't install 315's for me. Some lawyer crap about being 11% larger than stock diameter.

 

[1973Guppie]

good to know about the costco deal, I am considering these eventually as they have the 295 size which would be a nice bump up from the 285's as the bfg's run small big time. My 285's measure out to only 31 inches.

 

[wearsabrowncoat]

285's also too big of an increase for Costco's liability department. They are a 5% increase diameter over stock. Their limit is 3%.

 

[DudeAbides]

They told me that if you bring in just the wheels they can mount them, and just say they are for "off-road" use.

 

[Nay]

good to know about the costco deal, I am considering these eventually as they have the 295 size which would be a nice bump up from the 285's as the bfg's run small big time. My 285's measure out to only 31 inches.

The 37's seem to be as claimed at 36.5", at least relative to the Trxus claimed 37.3" (pic above). What is interesting, though, is claimed revolutions per mile is almost the same with the Trxus only having 3 more per mile.

This seems born out by RPM - both tires seem about the same RPM at 75 mph or the BFG even a bit lower. Probably because the Trxus had to be run at about 28-30 PSI to manage lateral balance issues while the BFG are at 35 PSI, but doesn't make much sense otherwise.

I bought through Discount Tire Direct at $372/ea with free mount and balance plus free shipping. Rims were $50 off for four. They wanted $434/ea at my local Discount Tire for the Trxus, and there would have been sales tax on top of that. Seemed steep...

 

[1973Guppie]

285's also too big of an increase for Costco's liability department. They are a 5% increase diameter over stock. Their limit is 3%.

wow, really? that is ridiculous, will just have discount match their price then!

 

[Nay]

I'm going through some much needed maintenance stuff and figured I'd update on the tires. They have about 22K now, some wheeling but nothing huge, and a full winter in just about every condition. They stuff cleanly on the 17x8.5 4.5" backspace rims and I have been running them at 29 PSI for the tire to run flat (no slight crowning and wander). Still getting 12 mpg city and 14 mpg highway. Very little tread wear.

I'm still pretty shocked out how good the ko2, at least in this size, was in deep snow and we had some good blizzards this year. Definitely MT class. It had some slip in icy conditions, but it was more like a slip and wiggle, and then it would regain traction. Glass half full says that's good feedback to the driver of worsening conditions, glass half empty says that's a typical AT with some bias to tread life. Either way, given the road performance and typical southwestern trail performance, and being completely round at 22K miles, all good.

I probably still miss the Trxus, but I guess you gotta grow up. Although, just bought a '04 Sequoia so family duties have shifted. Might be time for that third row to come out and...

 

[cahill]

Welcome back Nay, glad to see you around. I was reading through the "shocks - old territory could use an update" thread and kept thinking "I wonder what Nay would have to say". Glad you are back.

285's also too big of an increase for Costco's liability department. They are a 5% increase diameter over stock. Their limit is 3%.

I was able to get Costco to install 285's a few years back. They were a little hesitant but did do it. Maybe they changed their policy or maybe it was just the guy that day was willing to bend the rules.

 

[Tapage]

happen to know how much tire / wheel combo weight ..?

 

[2KCruiser]

happen to know how much tire / wheel combo weight ..?

Also have a 17" MB wheel with same tire mounted.