Would you recommend 10w40 instead of 30? I ran 30 weight in my nfr and it ate a little oil when I was hard on it.

 

10w40 is fine, I'm sure there are more than a few members who use it, though typically you only use it when you live in a hot climate. Mobile 1 isn't such a good choice though, it's got a high NOACK value, which generally means it will burn off more quickly than other oils, especially in these cars. Like iamxpL, I use Pennzoil Ultra, which has a great NOACK value, great addpack, and I was able to catch it on clearance for a good price. If you can't find any of that, I wouldn't hesitate to use Pennzoil Platinum as a cheaper alternative. If you want arguably the best oil for these cars, then look for AMSOil 10w30 Advanced Synthetic Motorcycle, but be warned that it's a bit pricey. Castrol Edge also seems to get favorable reviews, though I haven't tried that one yet.

Also, that Gunk Motor Flush should be safe for our cars. And if you can't find it for some reason, it's only about 90% diesel and 10% napthenic base oil, you could pour a quart of straight diesel or kerosene in, run it for a couple of minutes, and get the same results.

 

10w40 would be fine to run, some of the members run the rotella t6 and get good results. i run it in my STI currently. but i will be sticking with pennzoil since it had been very good to me.

@merlin yeah ive heard of good reviews of the castrol as well. and thanks for the good info on the flush alternative. Yeah amsoil users are very happy, theres a ton of UOA's for it as well.