Hi all, I have a stupid question for ya.

What weight oil am I supposed to be running in my '75 W200? It has an abused 360 LA in it with 75xxx miles (or 175xxx, the odometer could have rolled over). Right now I have some 5w30 in there, but I have a feeling I'm supposed to using something thicker. Thanks in advance for any info.

 

If oil pressure is good and it don't use a lot I would say that is OK.
I use 20w50 in my 87 and have since it was new but it usually gets colder where you are.
In the 96 I use 15w50 Mobil 1 and the 5th ave. 10w40.


The question ain't stupid. If you're not sure ask, a good to way to learn.
Charlie

 

Thanks charlie1935,

It doesn't use a noticable amount, but it does leak a little (either rear main seal or oil pan gasket). After being parked overnight there's always a quarter size dot of oil on the driveway.

As for oil pressue, on startup the gauge says 40psi, but when fully warmed up its around 17, and it doesn't rise with engine rpm. Good enough?

 

i used 5w30 in my 318 in 91 and i plan on using it in the 318 in 81 that i just bought when i do an oil change on it. i think the oil pressure is suppose to rise with the engine rpm. i know on my 91 i can watch the oil pressure gauge go up and down with the rpm. my 81 don't have a oil pressure gauge, just an idiot light.

 

Your pressure is within factory specs. I really like to see more than that. Also if you are depending on the factory gauge it may not be right.

 

Anything that isn't new gets 10w40 when I own it lol