Luis de Prat

Mobil1 came out last year with this new-and-improved 0W-40 grade that has even greater engine start up protection than the Mobil1 5W-50 I'm running now.

Should I change to the 0W-40? This car (944 Turbo 250 HP) never sees the track, but I do push it hard on the Euro highways, upwards of 150 mph now and then, not to mention the regular boost accelerations.

Will the 40 versus 50 be a substantial loss in protection at high operating temperatures? How much of a tradeoff versus the startup protection afforded by 0W grade over 5W grade? Would you guys switch?

TIA

Steve Weiner-Rennsport Systems

Hi Luis:

Everyone has an opinion on oil issues and I'll simply offer mine.

I would use the Mobil 1 15w-50 in your Turbo, not the lighter stuff. Your engine will be FAR happier in the long run.

The only times the 0w-40w makes sense is when the outside temps are well below freezing and you need peak cold start protection under those conditions that you are not driving the car hard.

Kevin

I wouldn't switch to the 0-40. The only reason why it is a factory fill for the 996 is for the new valvetrain. Also, you must realize that are engines don't benifit from moly-graphite coatings on pistons and other anti-wear agents. For the summer months I'd run a 20-50.

Luis de Prat

Mobil1 doesn't offer the 20W-50 grade here in Europe, so I'll stick with the 5W-50, which coincides with your recommendations in the upper range. It also costs significantly less than the 0W-40!

Thanks guys! <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />