I have some Kumho 27" M/T's (215/70R14) and some (very new) road tires 215/60R15. My question is, will I see much better performance in sand (like sand dunes, all dry) out of my M/T's? Or is it surface area that counts more.

 

The kumhos don't like flexing much so letting them down to 15psi doesn't seem to make much difference (6ply side walls I guess) But my roadies flex lots, even at 25psi. Although because they are on 6" wide rims I wouldn't want to let them down to much just incase the bead slipped off.

I think it is to a point. You always see people running those paddle tires in the sand, its more about width though. You want as much surface area as possible so you don't get bogged down.

I always kinda figured that a M/T is going to dig a hole a lot quicker too..

you would be correct, atleast, from what i read. ideally, bald all seasons probably work the best, but i have never driven in any kind of serious sand(new jersey has alot of sand, but i've never been on the beach).

yea but things with paddels have plenty of power to turn then, Surface area will be the greatest help,also air down a lot. The m/t's will dig holes faster, just keep momentum up if you dont have any balder tires to swap to.

Of cause if I'm climbing dunes I will probably want more tread right? Other wise I'd just lose friction.

 

I've been on the beach with my m/t's and found even if I rev to 4 grand and drop the clutch (sorry clutch, but I have to test these things) I don't get bogged. It just has too much grab to sink.. All on dry sand of cause, wet is a totally different story.

It might not be the best thing to do to your starter.. but I have found that if you get stuck in some sand.. instead of trying to burn up your clutch and dig four big holes and get stuck on your frame... shut her off.. put her in first or second.. and if you have your "clutch check" bypassed, hopefully, you can crank it over in gear and get it to lurch out of the sand.

actually, deep tread on subarus' probably isnt as bad as i thought it would. The relative lightness of these cars most likely helps them a lot. I remember reading a shootout in a magazine one time, and it was done with like a ford F250 or something like that. The all terrains were wayy better suited for that truck, but i could image that is one heavy motha haha. Running M/ts might not be to bad of a idea, as long as they are aired down, i'd say just use those..

Yeah, I guess it's only about half an hour to change over. I might be heading out to a place this weekend and seems its a 3 hour drive I wasn't to sure about putting the M/T's on, but they won't mind the road much. If I do go, expect some pics! maybe a video