500 mile update with the KO3’s (F Load) which I had installed two days ago. I’ve had a bit of everything to test them on - highway, snow, dirt roads, mud.
I have run at 37psi all around with the intention of lowering incrementally until I find a sweet spot.
Prior to this I had run three sets of the C Load KO2’s and personally they did well enough for me that I didn’t find a reason to change. My use of the truck is: 1) daily driver, 2) ~20 trips/year driving through the California desert and mountains chasing quail and chukar, 3) ~12 snow days/year in the California and Utah mountains. I would say everything below is pretty much to be expected, but maybe a helpful for those who have also liked their KO2’s but are considering a swap.
Stiffness: KO3 F loads are noticeably stiffer. You feel more small vibrations on road when going over cracks in the pavement. Off road, the washboard is harsher. If the truck came this way though, I’d probably never know the difference. So, I’d say it’s “fine”, but coming off 80k miles on the C KO2’s, I miss the softness. I’m hoping if I get down to 33 or 34 psi it will be slightly better, we’ll see.
Noise: Quiet, like new tires are. Can’t say they’re any different than new KO2’s.
Dirt roads: A little loss of traction on the washboard due to the stiffness. This is where I really missed the C loads. Here’s the best comparison I can make - imagine running washboard roads on C Load KO2’s at 45 psi.
Snow: Honestly, I was impressed. We got a foot of snow in Mammoth, CA. Snow driving was a combination of a short unplowed driveway, partially plowed roads/parking lots, and unplowed roads with ~4” of fresh snow. I drove around the neighborhood which has some pretty steep grades, where I would have expected some slipping from any tire. I intentionally got on the throttle to try to get them to slip and in 4H the tires hooked up nicely. For comparison, my buddy in front of me was running Falken Wildpeak AT3’s on his Ram and he did slip a little in 4A. I did the same roads again in 2H and the rears got a little loose going up the grade, but fully manageable. I think the KO3’s are noticeably better than KO2’s in snow from the limited time I’ve had them on.
MPG: This might be my biggest concern so far. I’ve averaged 13.7 (my own calculation). But this is with a lot of highway driving where I’d usually average 15+ with the C load KO2’s. I want some more time to really get a sense here (road from SoCal to Mammoth has a lot of grade and a headwind), but the truck does feel slightly more sluggish with the extra weight in the tires, in my opinion.
Bottom line: I am eager for C or D load KO3’s. I think they will be an improvement over KO2’s. However, gun to my head right now, I would say stick with C load KO2’s if you like them. I would switch to the KO3’s if you do a ton of snow driving or if you don’t think you care about the slightly stiffer ride. But then again, if you want to optimize on snow, there are other tires to consider too that aren’t an F load rating.