[androver]

I have a 1994 220 SLI and have been using Castrol Magnatec 10/40 oil, which I believe to be the correct spec, in the engine.

I have a couple of gallons of quality 15/40; would this be OK to use? What's accepted practice in garages where oil is bought in bulk - do they keep several grades in stock or stick to one?

Andrew

[RoverRevival]

They usually keep 10/40 semi on barrel and order in anything else.

Autofactors deliver within an hour....

[E_T_V]

10w40 for UK temperatures,

15w40 is probably ok for summers in the UK, but winters I'd stick with 10w40.

I run 5w40 in my T16 turbo.

[androver]

Thanks for the replies - will save the 15w40 for the nice warm summer months next year then

[Nudge]

I use 15w40 in my T16

[threelitre]

Given the 15W40 is no (semi-)synthetic oil I would not use it in such a relatively modern car. It will be OK even in winter, but you should consider using it no longer than 1/2 of the original change interval. All in all it seems more cost effective to use a good quality semi or full synthetic oil as per manufacturer specification. More important than the viscosity is the actual specification of the oil. A good quality oil from today should at least fulfil ACEA A3/B3.

Regards,

Alexander