How much dirty looking is engine oil from an engine after 3000 miles?
 

Dear friends,

If you have 2 cars (one is diesel and the other is gasoline) which
are subject to similiar driving conditions, how much difference in texture and appearance is the engine oil drained from each of these 2 cars (e.g. after driving for about 3000 miles)? Is it true that the engine oil drained from the diesel car looks like black mud while the one from the gasoline car will look dark brownish?

Thank you very much for your info.

Eric

Motor oil from a diesel will be very black within just a couple hundred miles, nature of the beast. I used to work on Detroit Diesels way back when and the oil was jet black in just a matter of minutes and the oil will stain big time.

My 560 on the other hand, with 181K on it, has oil the is a warm brown, about the color of tea, at 3K miles.

My '99 E300TD oil is black after ~100 miles as well. However, I can shine a flash light through the oil in the '94 wagon after 3000 miles quite easily.

Thank you very much for your precious information.

Best regards,

Eric

Dirty Oil
 

Hello Eric. This post really highlights to your other post re: what oil to use in a diesel. Because a diesel has higher compression than a gas motor, a larger percentage of fuel & combustion contaminants passby the piston rings & end up in the oil of a diesel vs gas motors. Thus your oil "Blackens" at a quicker rate. Also, the oil is asked to carry this heavier load of contaminants in suspension and still maintain it's lubrication & viscosoity levels. That is why several of us recommended Delo 400 as it is blended to maintain viscosity, is Highly Detergent also, & maintain it's lubrication capabilities while up against the fuel dilution from diesel engines.
Richard

Thanks Rogue. Your post is really enlightening.

Best regards,

Eric