Engine oil for petrol and diesel, what's the difference?

[TheNewGuy]

Just been buying some oil for my cars, one petrol and one diesel, and was wondering what the difference is between them or indeed if there is any difference. By this I mean what's the difference between a plain 10w-40 synthetic oil and a 10w-40 sythetic oil sold as 'specially designed for turbo diesel engines'? Is it just marketing or do they have some different additives? Would putting them in the opposite type of engine cause problems?

TIA,

Ross

[Panda76]

I could be wrong but I'm led to believe that diesel oil contains more detergents than a petrol oil.

[Deva Link]

Allegedly Mobil-1 and Mobil-1 Turbo Diesel were the same oil in different containers. The datasheets were identical.

Mercedes say to use MB229.5 oil for both petrol and diesel (.51 for diesels with DPF) and you'll often find the same approval number on both petrol and diesel oils.

[jagnet]

Aiui, diesel engine oils usually contain higher levels of dispersants to prevent the soot particles from agglomerating. Diesel engines, by their nature, create higher levels of soot in engine oil, as my dust sheet that I use for oil changing will testify to.

[TheEnd]

They tend to be moving away from diesel and petrol specific oils now, and most you'll see are suitable for both.

[rigga]

Posted this many times,but i can say that generally your local garage will take oil for diesels,petrols and turbo's from exactly the same bulk container.

[untakenname]

Diesel oil is allowed by law to have a higher concentration of zddp in it than petrol oil, its why people with older/higher performance cars prefer using diesel lubricant.

http://www.mustangmonthly.com/techarticles/mump_09...

edit: first link doesn't seem to be displaying for me so this one maybe of more use http://www.macysgarage.com/myweb6/ZDDP.htm

Edited by untakenname on Monday 16th January 17:45

[TheNewGuy]

Thanks everyone, I'll bare that in mind in future.