M110.094 oil weight
 

ok.. what weight to use in this engine.. not type.. I just need to know the weight

10w30?
10w40?
5w30?

eh?

Offhand, anything 1997 and older (diesel and gas) gets 15w40 unless otherwise specified.

I found out shortly after that its going to need

20w50!

insane

That is what I run in mine. The 15w40 is for diesels. I used to run it in my gassers too but I don't anymore. It will cause some problems in some gassers.

Tom W

I run 15W50 or 20W50 in my gas vehicles.

20/50 for the M110..esp. if you have Any kind of miles on it.. Also, be sure to adjust your valves!! It's commonly overlooked these days.

Jonathan

Such as...?

I stopped using 15-40 as well since the detergents work too well, clearing the false seals around my timing cover and causing leaks, and also because it is too heavy and makes the car vibrate (or rather, the overburdened oil pump does that).

My current rule of thumb is: With engine hot (at operating temperature) and when stopped while in gear: If oil pressure is above 1.0, then the oil is too heavy.

I have been using 10-40, and if the weather was colder I'd use 10-30.

Interesting, I won't buy a mercedes that has less then 1-1.5 bar of hot oil pressure.

If you look in the back of your owners manual it actually gives you a chart for temperature/oil type which should be used. Also stating that if you drive it Hard you should run a heavier oil.

Jonathan

I need to clarify that this is perfectly normal for me since my oil pressure guage is is quirky and does not always peg at 3.0, but usually at around 2.7. When it is behaving normally, and pegging at 3.0, the hot pressure is typically 1.3 or so.

my diesel has an idle pressure(hot) of 1.9 ( clearly under the 2 bar line) and I have 15w40 in it... normal for a diesel eh?

Diesels have more torque, so they can easily deal with the heavier oil.

When I use anything heaver than 10-40, it feels like I am in a massage chair, and the engine groans. :)

you may right but it seems that using 10/40 is counter intuative, I have always been told to use 20/50 in high milage engines.

I picked up around 0.5 bar (about 7.5psi) going from 10W40 to 20W50 in my 560 and 300SEL. I have around 1-2bar hot now, depends the style of driving... highway typically has a tad less than two.

I put the 15w40 rotella in my 84 500sec when I first got it and found that a hydraulic lash adjuster would stick and make the valve tap. When the car was good and hot it would stop tapping and after running the oil 1500 miles it would stop as well. I switched to 10w30 mobil one and the tapping stopped. I ran that one oil change and switched back to my beloved rotella and the tapping came right back. So next oil change I went back to the mobil 1 and stuck with that.

I think maybe there might be other things too but that is my experience.

Now I understand that oil is designed for different applications and engines are designed for different oils and you should use what is called for whenever possible.

Tom W

I had a tech who specified 20-50 for high-revving engines, but I did not follow his logic. (The faster a machine spins, the less I would want to inhibit its performance with a heavy oil.)

I think the kindest thing I can do to my engine is to relieve as much of the burden placed upon it as possible. With 15W oil, it was under visible strain, i.e. vibration, sound, and a jittery oil pressure needle -- as if the 15W had a harder time flowing through the filter. With lower oil weight, everything settles down.

Oils I have used ranged from 10W-30 to 15W-40. The ideal compromise was probably Rotella 5W-40 synthetic (but it still made me uncomfortable when driving in hot weather).