Napa is selling 0W40 for $5.47 a quart and I'll probably buy a whole bunch of it. Up until now I've run Mobile 1 5w30 with no apparent problems but after reading a recent thread I guess I should be running 0w40. My question is whether running this oil applies to my engine as well...it's an M52 not the M52TU. I've had no issues with 5w30 (that I know of)to date and I've got 250,000km on the car, but if 0w40 is what I should be running then I would like to make the switch. So I guess the question is does this apply to the M52.

Thanks in advance guys.