what oil

[david11]

is an oil made that can be used for both diesel and petrol engines,i was led to believe that the demands of a diesel are quite different than for a petrol engine,as one has a detergent in it.Some rapid fit outfits are saying they can

[mr rusty]

Diesels are much tougher on oils than petrols, which is why the oil companies all make diesel specific oils, but there are some dual purpose oils.

You need to know what it says on the can: Most oils sold in the UK and Europe have an ACEA rating somewhere in the spec on the side of the can, 'A' ratings are for petrol only, and 'B' ratings are for diesel engines. 'C' rated oils are the dual purpose ones,suitable for petrol and 'light duty' diesel engines.

there are subdivisions within the ratings as well, so if Mr Fastfit can't show you what's on the tin or explain (or indeed, understand...) the ACEA spec system, then go elsewhere, or, better, do it yourself.

[Toureman]

Castrol Magnatec is sold in differently marked cans for deisel and petrol engines but us exactly the same oil !

[fiesata]

main thing about diesels is they produce more soot so a good detergent is required look for the diesel specification mark and you should be ok

[robbie1953]

Be very careful it is easy to assume that the oil looks exactly the same, but diesel engines run much cooler than petrol engines and the forces exerted on the crankshaft bearing are much higher than in a petrol too, so the oil has to work harder at a lower temperature than a petrol engine and therefore will have subtly different polymer additives for oil viscocity control.

Unless it says it is suitable for a diesel engine then don't use it.

I would be very dubious of an engine that said that it was suitable for both on the tin anyway.

You can't use petrol in a diesel so don't use the oil either.

[JamesQ]

Back in my Army days, we used exactly the same oil in both petrol and diesel vehicles, and they clocked up quite unblievable mileages without any problems.

Diesel engines have been around since 1893, but I only recall seeing oils marketed as 'specially for diesel engines' in the last ten years or so.

All that really matters is that the oil meets the specifications that the manufacturer of the vehicle specifies - that oil might say 'Diesel' on the can, or it might not. As long as it meets those specifications, it's perfectly fine.