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engine oils?

Posted: Tue May 29, 2007 4:54 pm
by GQ Bear
Is there any or much difference between Deisel engine oil 15W-40 and Petrol engine oil 15W-40? I can get the first for nothing from work, is it safe to put in a petrol engine?

Posted: Tue May 29, 2007 6:21 pm
by dogbreath_48
My understanding is that the diesel oils have more detergents and particle loading capacity (incorrect term, i'm sure). Some fleet's use diesel oil in their petrols.

Posted: Tue May 29, 2007 7:15 pm
by PGS 4WD
I've put diesel oil in petrol cars for years when the petrol engine is carboned up, and change it regularly untill it cleans up, diesel oil does have more detergents and the ability to hold particles in solution better which means the crap comes out with the oil at the change, thats why you should change your engine oil at operating temp so the particles are in solution not settled on the bottom.

Joel

Posted: Tue May 29, 2007 7:16 pm
by tweak'e
generally you can use deisel oil in petrol vechiles but not petrol oil in deisel vechiles.

easy way is simply look on the container to see if its specs match your vechile :)

Posted: Wed May 30, 2007 5:53 pm
by Ruffy
Diesel oil in a petrol will be fine.
Even most modern diesel do not require a 'diesel' oil as such as they burn alot cleaner.

Posted: Wed May 30, 2007 6:05 pm
by tweak'e
Ruffy wrote: Even most modern diesel do not require a 'diesel' oil as such as they burn alot cleaner.
that would have true up untill around 2000 and most definitely before the comman rails came out. basicly the high EGR motors produce large amounts of soot with contaminates the oil.

Posted: Wed May 30, 2007 6:28 pm
by GQ Bear
Thanks. This'll make services a bit cheaper :D

Posted: Wed May 30, 2007 7:16 pm
by trains
Have used diesel oil in pettys for years.
however I have found that the fuel does dilute the oil, and it seems to get watery near the 5k mark.
Hey if its "cost effective" then change it out when its ready.

Trains

Posted: Wed May 30, 2007 7:43 pm
by PJ.zook
Doesnt the diesel oil make petrol engines that have done lots of kays smoke? Due to the higher quantities of detergent cleaning off all the carbon buildups around the rings which actually help plug gaps and stop oil bypassing?

Posted: Wed May 30, 2007 8:30 pm
by Mulisha
PJ.zook wrote:Doesnt the diesel oil make petrol engines that have done lots of kays smoke? Due to the higher quantities of detergent cleaning off all the carbon buildups around the rings which actually help plug gaps and stop oil bypassing?
I would have thought the same thing as well..

What happens with diesel oil in a LPG engine with a turbo?

Cheers

Rick.

Posted: Wed May 30, 2007 9:55 pm
by zagan
When I was last looking at diesel oil.

I looked up in the book and you could use some petrol oils in a diesel but the important bit was what standard the oil complies with.

No good buying diesel oil for a petrol motor if it's not going to comply with the correct standard for said petrol motor.

For my dieel it needs CFD3 and Castrol GTX is CFD6 it's above the current standard CFD level which is 5 in new euro diesel motors.

You also get AFD amercian I think that goes to 5 I think and GTX is above standard aswell.

An interesting thing is, some of the diesel oils don't have this standard on the label so no idea wheather they'd be able to comply to the standard.

The petrol version is CFD 5 that's the reason why you can use it in a diesel but it's thiner I take as the Diesel GTX oil is pretty thick compared to the petrol oil.

I would be looking up the book and then looking at all the labels first then buy what you want to pay.

There's around 6 different standards for oil, Castrol has them all listed on the label, others might only have 3.

Posted: Wed Jun 20, 2007 9:42 pm
by krf_bb
a good engine oil to use is the penrite hpr40