diesel engine oil in gasoline punto?

problem?

Diesel engine oil usually contains quite strong detergents to dissolve and suspend the carbon (soot) particles. With any older petrol engine, this can have a similar effect to flushing oils, removing every bit of carbon it can find. This may then reveal leaks, and can remove the carbon around piston rings, creating compression pressure issues.

From a lubrication viewpoint, should not be a problem. If you've just used it to top up, it should be ok. If you've done a complete oil change, it may well get blacker quicker than expected. If it does, change it again sooner rather than later.

The original VW Beetle aircooled engine used to specify diesel engine oil, although this was supposed to be used all the time. Presumably the high detergent qualities were beneficial to the aircooled engine.

shouldnt car work better without carbon deposits everywhere

flisko said:

shouldnt car work better without carbon deposits everywhere

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in thoery yes!

However the carbon on piston rings things - its a no
If you remove the carbon thats help create compression - suddenly you start to loose compression and oh - you've now got a car with a misfire/smoke issue

removing carbons from cylinder heads and tops of pistons - yes, returning the original flame spread and it allows for the correct mixtures for the cylinder like new can help

If you have a shell thats got carbon surrounding it - it may also help maintain a good oil pressure, if the carbon was removed, and it allowed a faster flow = low oil pressure = Something else is now getting affected

Oil leaks on say a sump or switch - i wouldnt care about, easier to fix, but not for the main mechanicals

Ziggy

What oil exactly is in there?
Many modern oils are dual use. I use diesel mineral oil for the bike because it has a better additive package and no slippery stuff. For many years I topped off petrol cars with diesel oil to get a bit more detergent.

Brendan W said:

What oil exactly is in there?
Many modern oils are dual use. I use diesel mineral oil for the bike because it has a better additive package and no slippery stuff. For many years I topped off petrol cars with diesel oil to get a bit more detergent.

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now that makes sense to me

Say it takes 5 litres
If you put 4 litres of """petrol"" stuff in
and 1 litre of ""diesel"" in, and you'll be probably get a clean running lump

But i think alot of petrol engines are now using same oil too - regulary see for petrol or diesel, so either the petrol has the cleaning detergents or the diesel is lacking it

Tbh if i had a crappy running engine (lots of old oil) i'd run about 5K with a strong detergent oil to clean the whole block out
Or wait till the oil goes black - which evercomes first

Ziggy

Running from new with a high detergent is fine, but adding this to a well worn engine creates lots of issues.
Back in the early eighties, when engines wore faster, a large parts supplier bought in some high detergent oil for its own brand. As it was cheap, it found its way to a lot of old engines, which promptly got cleaned out and used lots of oil, lost compression, leaks, etc. Brand damaged, lots of 'warranty' claims to fight. All the detergent does is highlight the problems that were hiding, but the owner does not see it that way.

So using a high detergent oil can be anything from fine to a disaster, depending on the underlying condition of the engine. Don't blame the oil.

And just to make things simpler you had back then carburetted motors with points ignition and mineral oils so you had lots of options for clogging up the combustion chambers, valve seats and rings.
Anything post 1990, fuel injected, cat, electronic ignition control etc that has had a reasonable diet of semi-syn is much less of a risk than lashing detergent into a Mk I Cortina.
As a general rule the state of the top end is a reasonable indicator of the amount of carbon barnacles throughout the motor. Fuzzy black stuff there......... you probably don't want to find out what will happen if it all breaks lose.

havent put in anything, just saw cheap price for 10l of oil and it says on box its for diesel engines

What weight, ACEA or API grade, mineral or...................?