I know with the 20”+ tires there are sidewall concerns, but what about with 18s? For those that air down, how low do you go?

 

Lot's of opinions out there. I like to air down about 20% of the recommended tire pressure. For light load which is suitable for the driver & 1 passenger without the loadspace full to the brim with camping gear, that would be around 26psi. For sand, I go down to 30% or to about 23psi.

However, you asked specifically about the Goodyear Wrangler Adventure. My strong recommendation is to take a look at the tire construction info imprinted on the sidewall. Although you've an XT tire, they are not necessarily built to withstand sidewall damage that maybe encountered on a rocky trail when aired down. I suggest at a minimum if airing down, you'd want Belt: 2 Steel, 2 Polyester; + 2 Polyamide / Sidewall: 2 Polyester. 3 plys on the sidewall like what is on the KO2s would be even better. Avoid airing down with rayon sidewall construction.

 

For the loose deep sand of eastern Long Island beaches I go down to 20-22 psi. This is the only off roading I have done. So far so good.

 

I signed up for a guided day at an off road park in eastern PA a month or so ago. Lots of Wranglers, a few Tacomas, and my 110S P300 with 18” Adventures. All stock - this was a “new to off roading” class.

As we got into the park and were about to tackle tougher terrain, the guide had us pull over and aired down all of the vehicles to about 15 psi. I spent the next five hours on rocks, sand, water and other obstacles.

No problems at all, and my Defender did remarkably well on everything.