haha how is stretching a tire reducing contact patch?? It's completely the opposite. Nankangs are just really shitty tires. I used them for drift once and they made brown smoke and chunked imediately. Worst tire I've ever used. Also 37-40psi in a 235-40 is not really too much, but I'd probably stay around 35 though. The lower profile you go, the more pressure you need to run. Just don't go over the max rating on the tire.
