I've been airing down my 33" 275/60 R20 K02's w/ 1.5" rod lift to no less than 50% of the normal load psi.. so around 24-25 psi (50% of 48-49 psi). This is based on the teachings of a pretty experienced 4x4 offroader/recovery expert/outfitter in the area.

And.... no issues yet.

Yes, I wish I had 18's so that I had more sidewall. But it's very unlikely I'll actually do the caliper swap/grind and go to 18's.

FYI -- I disagree with Insider's comments about a year ago saying "never air down on 20's". He may be correct from a manufacturer legal perspective, but I've experimented, in snow and non snow conditions, with the stock Goodyears and now these 1" larger K02's.... and *not* airing down is a mistake. The difference in traction on snow between airing down and not is noticeable, and material. And also in mud / forest conditions. I just don't think his perspective is an official position... many of us have taken his historical comments for gospel, myself included.

Airing down helps -- 20's or not -- and I think what is important is to air down no more than 50% of normal tire capacity, as a starting point.

Would I air down 22"s. No?
Would I replace 22's with 20's? Yes.
Do I think @NoGaBiker is right in having a set of 18's for offroad and 20's for everyday onroad use? Completely. Just not what I've got in my kit.

 

Thank you both. This is helpful. I tend to agree with you that running on-road pressures of 40 to 50psi in wash board roads cannot be either comfortable for the occupants or good for the suspension components. I remember seeing a YT video of a guy going out on a trail with a Defender without airing down and having a catastrophic suspension failure mid-trail and being completely stranded. Granted the guy had tons of mods, including a massive lift - so not sure if his mods somehow influenced. Can't find that video now, but it makes sense to me that the beating the suspension took from hard rock tires contributed to his trip demise. I am leaning towards airing down to between 32 and 35. I will report back after the trip to help the community.

 

I just watched the TFL video for the first time. I have not been to Moab or anywhere close. But, I have happily taken my Defender many times to rocks similar to what was in the video and was able to work through the situation successfully.

But, never could I be happy in rock crawling to that degree without a serious set of Rock Sliders. That's the best money I have spent.

Blowing tires is embarrassing, sure. Landing the Defender sill on a rock without protection is very likely a much worse case.

Enjoy!

 

Those guys (TFL) are the worst off roaders I have ever seem.
I cant count how many times I have watched them try to go over an obstacle by stopping right before the obstacle then wonder why they're having trouble climbing a little pebble.
They would be shocked if they learned how much difference just a little bit of momentum helps.
That's just 1 example.
Crappiest off roaders.

 

I also take issue with how aired down they were on the 20's that were on their Defender, especially with those tires. I know their schtick is to only offroad with what came from the factory, but the GY Adventure tires are notoriously thin on the sides. Airing down as much as they did was probably WAY worse for those tires than just leaving them inflated on that particular trail.

 

Only those 2 morons could pop 2 tires.
Don't mean to call them morons, they seem like nice enough guys.

Yeah, you cant air down those highway tires they got on their truck.

Actually I DO know someone who popped 2 tires...At once!
I was riding in my buddy's Gremlin in the early 80s....Highschool.
He took a corner a little quick and either popped 2 tires or they slipped the rim.
It was a great source of entertainment for all.