Pros: Decent off-road performance with excellent on-road traction, handling and treadwear
Cons: Fixed price for two years meant higher dealer prices
In the mid 90's, BFG got bought by Michelin, and Michelin poured in tons of R&D money. BFG invented the idea of an A/T tire in the mid-70's, but didn't spend money improving on the original design. The KO came out in the late 1990's as a redesign of the BFG AT. They redesigned the carcass, keeping the 3-ply sidewall but improving flexibility. They also redid the rubber, changed the sidewalls to have tread overlap, put in a rim protector, and deeply siped the treads for improved wet/snow traction. My wife and I spend a lot of time driving off-road, and tires are the number one upgrade to any 4x4 to make it better offroad, hence the historical context.
I put a set of 30x9.5 BFG AT's on my 97 Ranger 4x4 right after I bought it. They were toast at 25K. They were tons better than the Firestone Wilderness AT's Ford put on my Ranger, but that's not saying much. On road, they were stiff but handled better than the Firestones. Off-road they were a million times better than the Firestones (a much more typical "AT" tread design). They wore unevenly, I should have rotated them more than the 5K recommended. These were the "before" AT's, then we got the "after" AT KO's.
HOWEVER - in Feb of 2000, we heard about an upcoming investigation of Firestone tires, so we put 31x10.5 BFG AT KO's on my wife's 98 Explorer 4x4. With 26.5K the Firestone's weren't half worn, but we took them off and never regretted it (Firestone stiffed us for any $$ because we took them off before the recall, even though we kept the tires at the time and physically turned them in to their local dealer). The KO's were $99 at the time, a real bargain. They went up and then came back down, probably about $100 again.
The change in handling, grip, smoothness (big surprise here) and resistance to hydroplaning made them a slam dunk repeat buy for on-road use. One scary wet lane change in the Firestones was enough to convince my wife that we needed new tires. Plus, the Firestone's were pathetic (worse than pathetic) in snow and off-pavement. I was curious whether such an aggressive tire as the KO would work well in water, but there are no such scary events with BFG's. They are great in light snow and wet/dry snow environments, and the siping pays off big time on wet running water. We had two punctures in 26.5K with the Firestones, 0 punctures in 40K since on the BFG's.
A year and 20K miles later, they went off of my wife's truck and on to mine, and she got another set ($113 each). I have another 10K on them on my Ranger, they wear even better on the lighter truck. I can see why they offer a 40K mileage guarantee. We'll buy another set this tax return time and do the hand-me-down trick to the old Land Cruiser.
We put on about 1.5K off-pavement, maybe 300 miles off road, with the first set. So far on the second set, about 1000/500 - no trips to Death Valley this time (lots of wasboard roads there). The AT KO's are perfectly adequate for dry weather offroading. Good control, great puncture resistance (LOTS of rocks and branches, no damage to aluminum wheels even). They air-down well, getting better traction though with less clearance. On fire/logging roads they're good, but running around our property with no roads at all they're amazing.
I have a good friend with Bridgestone Dueler AT's on his 4x4 - I wouldn't trade in a heartbeat, even if it weren't Firestone's parent company. He was aghast at one particular place where my wife calmly motored up the hill, going so far as to start opening the door to get the shovel - he was convinced we would have to dig out. Those Bridgestone's are an aggressive looking tire, but all AT's are not created the same. He can't get BFG's on his continent, but he went back to Africa with a good story about "Amurrican Tyres."
They are NOT mud tires - people complaining about poor mud performance from an AT are misunderstanding the purpose of an AT. If you drive around town for a day on mud tires, you will KNOW why two sets of tires is reasonable. An AT will drive comfortably on the road but still drive offroad where no normal street tire would survive. A mud tire is specialized for offroad use only. If you see someone driving on muds regularly, they probably bought the tires for bragging, not offroading. For what a set of good muds cost, and given how poorly they handle/sound/wear, why would you tear them up on the street??
For on-road life, I have about 4K on my set of muds for my Ranger. In another 2K, they will have worn down below the 3/16" tread depth required by many clubs for offroading. After 5 years of hard use, I'm perfectly happy to buy another set, but imagine if I'd run them on the street the whole time?? That's what AT's are for.
Michelin still makes the best quality tires on the planet - but their AT tires are pathetic offroad. I'm comfortable that they have raised the build quality of BFG to a reasonable standard. I have no qualms with my wife driving my boys around in her truck, knowing they're running AT KO's. Can't see getting any other street tire EVER. Even if you don't ever offroad your truck, they're a good tire - but I would also look at Michelin.