quote:I'd say it really depends on the year and make of the engine. Most newer BMWs spec Group III 5W-30 year round. A friend's '01 Audi A4 calls for 0W-30, 5W-30, or 5W-40 year round. The Corvette specs M1 5W-30 and I've never heard of those things sludging up. I've run M1 5W-30 in various Hondas and even my old turbo SAAB, and those engines stayed clean. I lived in southeast Asia for several years and the Honda dealers specify Shell Helix 20W-50 year round for Civics. That oil is so thick that those poor little 1.6L engines stuggle just to maintain idle speed--the gearshift shakes like mad! When I saw that, I dumped the 20W-50 and replaced it with M1 5W-30. I was confident that M1 5W-30 could handle the high heat (35'C), humidity, and massive traffic jams... and I was right. The engine performed MUCH better with the proper 5W-30 weight and no longer shook at idle. Like night and day... the engine finally loved to rev, just like a good Honda should. I never had a consumption issue, nor an engine cleanliness problem. To this day that car runs great. It's almost 10 years old now, A/C running day in, day out, and massive traffic ALWAYS. 10,000 km oil change interval. Camry/Sienna V6 sludge-monsters excepted, I don't think you'll ever have a cleanliness problem running Mobil 1, even with lighter weights such as 5W-30. So I wouldn't be so quick to condemn every 5W-30 for every engine out there... Thicker weights like 15W-40 and 20W-50 are not appropriate for all engines, even in hot weather. Jason
Originally posted by Dr. T: I was going to say that this chart is actually a bit conservative. My BMW stops a 5-30 at 5C (and not 15C). I used to think the same way. But, I now agree with the charts too. Although there is some variation with synthetics, the viscosity illustrated holds true if you want a long-lasting and clean engine. I've said this before...for all you 5-30 users....there's always auto-rx later on....to clean up the garbage left by the "fuel-economy" oil.
quote:Column A shows "Leichtlauföl" - oil that contains friction modifiers and that also meets VW500.00 (replaced by VW502.00). Those oils are to my best knowledge all synthetic oils and almost always "energy conserving." Column B shows multigrade oils, which could be HC, blended, or dino oils. That chart cleary shows that synthetic oil protects at high temperatures better than a dino oil of the same viscosity range. Interesting that your 2001 manual shows no viscosity chart. Do you have a 2.8 30v or a 1.8T?
Could it be that "A" is synthetic and "B" is dino?