I run 10w-30 because I do use mine to clear now in winter and I want the slight advantage of thinner lube for the starting ease. I don't have turbos, but even if I did, I'd still use 10w-30 for the winter starting issue. However, 15w-40 would also suffice quite well, IMO. I cannot find any reason to think that either would have any wear protection differences. I've run a few UOAs on mine over the years and found nothing but desirable results.