Castrol 5w-40 or Mobil1 0w-40
Discussion
Both will do exactly the same job when the engine's up to temp - they're both 40-weight oils when hot so have the same viscosity at typical engine operating temps. The Castrol will go gloopier (i.e. thicken-up more, or become more viscous) at room temperature and below as it has a higher W rating at 5W rather than 0W. This means the colder it gets, the less oil gets round your engine to lubricate it when you start up in the morning.
The engines are designed to work with 0W40 or 5W40 so if you aren't anticipating any really cold weather, either will do nicely. The thing to avoid is oil with higher than 5W ratings (as this is too thick when cold) or higher than 40-rating as it will be too thick when hot (unless you run your engine hotter than normal - e.g. regular track use).
The engines are designed to work with 0W40 or 5W40 so if you aren't anticipating any really cold weather, either will do nicely. The thing to avoid is oil with higher than 5W ratings (as this is too thick when cold) or higher than 40-rating as it will be too thick when hot (unless you run your engine hotter than normal - e.g. regular track use).
Edited by Ian_UK1 on Wednesday 21st July 17:01
Castrol Edge 5W-40 is a Porsche Approved oil, and you won't go far wrong with it.
I use Fuchs Titan Supersyn 5W-40 in mine. On my 996 C2 I found it all but eliminated the startup tappet noise and occasional puff of smoke. I still use it on my 996T and it seems fine.
I'm not sure why people get so obsessed with M1 0W-40. There are more 5W-40's on the Approvals List than 0W-40's. I might have a different opinion if I lived in Alaska though. Just my 2p's worth.
I use Fuchs Titan Supersyn 5W-40 in mine. On my 996 C2 I found it all but eliminated the startup tappet noise and occasional puff of smoke. I still use it on my 996T and it seems fine.
I'm not sure why people get so obsessed with M1 0W-40. There are more 5W-40's on the Approvals List than 0W-40's. I might have a different opinion if I lived in Alaska though. Just my 2p's worth.
billywhiz said:
Noticed in Costco they had started selling castrol edge next to the mobil 1. it was £23 +vat for 5 litres of mobil one and £26+vat for 4 litres of castrol
but you do get it in a prettier can
brilliant news, do you know if its a permanent thing or just that they happen to have a batch in?but you do get it in a prettier can
Pugley said:
Just another consideration:-
If your car leaks or burns any 0w -40 it will leak or burn less 5w -40, or even less 15w - 50..............generally speaking of course
Sorry but you're completely wrong here. 0W-40, 5W-40 and 15W-40 are all (nominally) equally viscous at normal operating temperature. The difference is in how much more viscous they become as they get cooler. 15W is thicker than 5W is thicker than 0W at room temp and below. All of them are a LOT thicker when cold than when warm.If your car leaks or burns any 0w -40 it will leak or burn less 5w -40, or even less 15w - 50..............generally speaking of course
If you want an oil that's thicker (more viscous) when hot, you need a 0W-50/60 or 5W-50/60. These oils will still flow well at low temps but not thin-out as much at operating temperature.
Also bear in mind though that if you use an oil that's thicker when hot, you will get LESS oil flow around your engine for a given pressure. Sure the positive displacement pump will move the same amount of oil irrespective of the viscosity (but use more BHP to do so with more viscous oils) but the higher the viscosity, the more of it will end-up being dumped back into the sump (via the pressure relief valve) and not lubricating the engine.
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