Airing down ... 18's or 19's for sand ?

[nrgetic99]

In the summer I do like to be able to run out on the beach while I am in the Outer Banks of NC. For all my previous vehicles, I typically run an A/T tire which I air down to between 12 and 15 psi.

My 03 4.4i Sport came with the staggered set up and I now have some Pirelli Scorpion Snow and Ice 255/55/18's on 8.5 x 18's.

I would like to try the X on the sand this summer and I know footprint and floatation are what matter which is the 6 million dollar question. I would feel more comfortable airing down the 255/55/18's than the monster 285/45/19's as I probably have a very stiff sidewall on the 19's (Diamaris) but in fact, the un-aired down 285/45/19's may offer a bigger footprint than the 255/18/55's when aired down.

Then add in the fact that the 18's have a very agressive block pattern ...

Any suggestions ? My gut is air down the 18's.

David