kisakron

Just a heads up to you guys who help out here on the website.
Napa has Formula M for $5.99 a auart.

kajtek1

It is only 229.5 classifications, so not too many modern MB diesels can use it.

Futureal

Don't put Mobile1 in your Mercedes Diesel engine. I learned the hard way.

gkgeiger

Has MB issued a bulletin that Mobil 1 is not be used. All I read here is Mobil 1 bashing.



Under the hood of my ML250

John CC

My car has the same sticker, but not all Mobil 1 oils, M1 Formula M in particular, meet the spec for my engine (229.51)

The only one I know of is M1 ESP and it doesn't come in 5W-40, as far as I know.

kajtek1

Those stickers come from years ago, when Mobil1 and MB USA had some kind of promotional deal.
Since them some M1 oils lost their approval, when some of them got new approvals.
I always advice to check MB site for oil approvals before each oil change. Technology changes on weekly bases those years...............
Better yet, do oil tests

gkgeiger

ESP is .51 & .52 rated. I have no more to say.

Etienne Lau

@gkgeiger Some of us will not use ESP even though it's .51 and .52 rated because it only comes in 5W-30 and nothing else. I live in DFW, TX and I prefer to run something that is .51 rated and supports 5W-40 due to the high heat situation here in TX, 102F+/39C+ for weeks at a time. I will not run .52 as no one sells .52 in 5W-40.

kajtek1

I run 5W30 in 120F heat in Las Vegas just fine.

lkchris

Your engine is water cooled and a thermostat in the cooling system maintains specified engine temperature. The radiator is sized correctly. Ambient air temperature has ZERO affect on your engine temperature.

Etienne Lau

Don't know about you, but I follow what's written in the owner's manual: Oh, and also read what the "Select an engine oil with an SAE classification suitable for the prevailing outside temperatures". Note it also states, my OM642 can use 228.51, 229.31, and 229.51

kajtek1

Not quite.
Thermostats do have their "start opening" temperature and "full opening" temperature, what per my experience is about 7 degrees F.
So most of my diesels on colder days operate at 78C, what is start of opening, when at 100F the engine will have 85C while under the load, or 78C, when coasting downhill.
Than comes 120F day and the radiator will get all hot till aux fan kicks at about 95C.
Obviously the dummy gauge on cluster will not move from the center position.
As for comparing the oil weight, suppose 30 weight oil in 229.52 category will give better protection than 40 weight from 229.51 category, but that is not something car owner can measure.