Originally Posted by Alstann

Both of those tire choices are very nice tires - although, they are both suited for different purposes. I've personally owned both tires, so I'll throw my 2c in!

First off, if we want to talk about sizing up the tires, there are several combinations you can do, such as a 245/40 and 285/35 (stock NISMO sizing), or a 265/35 and 305/30 (beefy setup). With an online size calculator, like you've been using, you can play around with sizing a bit to see what matches up nicely.

As for sidewall bulge and squirmy handling, something I can note is that the RE970AS have SOFT sidewalls. I had a set of 4 on the car for about 50 miles before I decided I hated them. The RE970AS have phenomenal grip, though. They hooked up better than my stock RE050A (I ran a 255/40 and 295/30 setup with them - it was weird, I know), but the sidewalls were so mushy and soft. It ruined the experience of the car for me. I loved how the stock tires felt very stiff and confident. However, if you don't do spirited driving often, and you want a tire that lasts, the RE970AS did that great.

I personally ended up doing a compromise setup - I ran S-04 in the front, and RE970AS in the rear. It combined the stiff sidewall up front for handling and stability, and the grip and longevity I desired in the rear tire. It was weird, but worked for me. Others said it was a bad idea.

Overall, if I had to do it again, I would run S-04 all the way around again. The S-04 handled better than the stock tires, had plenty of grip, and the sidewalls were awesome. I would trade that over the super long life of the RE970AS. Of course...if money isn't an issue, you could ball out and go for RE-11 or PSS.