smart51
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| posted on 5/6/15 at 03:21 PM |
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Diesel engine oil / petrol engine oil. Is there any difference?
It's been bugging me for a while. Shops sell two types of 5W40 engine oil, one for diesels and the other for petrols. Is there any difference
between them?
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cliftyhanger
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| posted on 5/6/15 at 03:37 PM |
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Probably. bear in mind that there are individual manufacturers specs for oil, ford, vw, vauxhall etc are all a bit different.
Also depends on the age of the engine, some are fussier than others.
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haz87
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| posted on 5/6/15 at 03:41 PM |
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I believe derv oil has a stronger detergent within the oil. Probably a fair few other additions but unsure
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mark chandler
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| posted on 5/6/15 at 05:38 PM |
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More detergent in diesel oil, I used to run my v8 rover on it and it stayed lovely and clean inside instead of the usual sludged up mess you find.
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Angel Acevedo
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| posted on 5/6/15 at 06:01 PM |
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quote:
Originally posted by mark chandler
More detergent in diesel oil, I used to run my v8 rover on it and it stayed lovely and clean inside instead of the usual sludged up mess you find.
Do you reckon it would be a good idea to run an oil change every 4 or 5 changes?
We had a V8 a few years ago with bad seals and we would recover aviation oil and pour as it consumed, I remember that the innards of the valve cover
wee clean as a new engine. I think it was the amount of detergent on av oil.
Beware of what you wish.. for it may come true....
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britishtrident
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| posted on 5/6/15 at 07:38 PM |
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Back in the days of mineral oils there used to be big difference in the amount of detergent and anti-varnish additives although many mineral oils sold
for petrol engines contained sufficient additives to meet the minimum demands of specifications for diesel engines. Less difference these days as
synthetic oils are more resistant to breakdown at higher temperatures which causes sludge and varnish.
If you want an engine that is clean internally run it on synthetic oil.
Incidentally synthetic engine oils were developed by the Nazis during WW2 to resist the extremes of temperatures lube oil is exposed to in jet
engines.
[Edited on 5/6/15 by britishtrident]
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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v8kid
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| posted on 5/6/15 at 08:56 PM |
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quote:
Originally posted by britishtrident
Incidentally synthetic engine oils were developed by the Nazis during WW2 to resist the extremes of temperatures lube oil is exposed to in jet
engines.
[Edited on 5/6/15 by britishtrident]
I don't believe it! Its fascinating but I don't think its true. What's the source of you info and is it credible to our modern
understanding of what synthetic oils are?
In anticipation
Cheers!
You'd be surprised how quickly the sales people at B&Q try and assist you after ignoring you for the past 15 minutes when you try and start a
chainsaw
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adithorp
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| posted on 5/6/15 at 10:32 PM |
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Back in the day, before synthetics were common, there was a lot more detergent in diesel oils. As the oils (and detergents) improved the the
difference became less and in a lot of cases the oils labeled as petrol or derv specific, were in fact the same stuff. It was just packaged that way
because the buying public expected it (heard same story from both Shell+Valvoline technical guys).
There is a difference now though with the introduction of DPF's as with them you need a low-saps/low-ash oil. Use a none low-saps oil and your
DPF will soon block up.
The specific VAG/BMW?Merc/GM/Ford/etc specific oils might all be for slightly different OEM requirements but again, the oil companies have oils that
meet most/all specs, but find it often sells better (and often at a higher price) if packaged separately.
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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smart51
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| posted on 6/6/15 at 08:04 AM |
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Right, so there's no difference in the oiliness, for the same grade. But Diesel engine oil is perhaps better for cleanliness. Except for cars
with a DPF, you could top up with either and it would make little difference.
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SJ
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| posted on 6/6/15 at 08:11 AM |
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All the oil I've bought recently has been for both petrol and diesel. It was fully synthetic Ford spec. though.
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adithorp
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| posted on 6/6/15 at 09:19 AM |
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quote:
Originally posted by smart51
Right, so there's no difference in the oiliness, for the same grade. But Diesel engine oil is perhaps better for cleanliness. Except for cars
with a DPF, you could top up with either and it would make little difference.
About sums it up but... There's no real difference in "cleanliness" anymore either and it's often the same oil in different
packaging (excepting the low SAPs). There's no reason not to use the low SAPs, DPF friendly, oil in a petrol engine either, other than the price
and it will be listed for both.
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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