Hi!
In general, why would one ever choose a 5w-xx, 10w-xx, 15w-xx or 20w-xx over a 0w-xx, if a 0w-xx in your viscosity grade is available?
More specific, can I, under almost all circumstances, safely change from a 5w-40 to a 0w-40?
The reason I'm asking, is that I have an Mercedes Benz 420SE (V8) from 1990 with 110k miles, that I'm wondering about changing both brand and viscosity grade on. I bought it last year, and the service manual states that it's been running on 5w-40. It has some slight valve train chatter when warmed up, but it's not bad, the cams were new two years ago. It's an SOHC design with hydraulic tappets. It's currently using around 0.6qt per 1000 miles, but there is no blue smoke or visible leaks.
I'm currently using a 5w-40 no-name rebranded oil that meets the latest MB 229.5 spec, but I want to see if Mobil1 0w-40 New Life may dampen the valve chatter a little when the engine is hot. Obviously not because of the change in cold viscosity, but just because the Mobil1 may be a better oil. The alternative is Mobil Super 3000 5w-40.
In general, why would one ever choose a 5w-xx, 10w-xx, 15w-xx or 20w-xx over a 0w-xx, if a 0w-xx in your viscosity grade is available?
More specific, can I, under almost all circumstances, safely change from a 5w-40 to a 0w-40?
The reason I'm asking, is that I have an Mercedes Benz 420SE (V8) from 1990 with 110k miles, that I'm wondering about changing both brand and viscosity grade on. I bought it last year, and the service manual states that it's been running on 5w-40. It has some slight valve train chatter when warmed up, but it's not bad, the cams were new two years ago. It's an SOHC design with hydraulic tappets. It's currently using around 0.6qt per 1000 miles, but there is no blue smoke or visible leaks.
I'm currently using a 5w-40 no-name rebranded oil that meets the latest MB 229.5 spec, but I want to see if Mobil1 0w-40 New Life may dampen the valve chatter a little when the engine is hot. Obviously not because of the change in cold viscosity, but just because the Mobil1 may be a better oil. The alternative is Mobil Super 3000 5w-40.