Understanding the oil spec table

[Somebody]

So, I bought a manual for my 5.0 v8, and this is the oil table:

This looks really confusing because they seem to all overlap a lot.

Doesn't that table basically mean ''as long as you live on planet earth, and not in Siberia or the Sahara desert, use pretty much anything''?

I can't see any other way to interpret it.

I mean, it shows pretty much every single oil in common usage being suitable for pretty much every temperature range ever.

Or am I just reading it wrong?

What would you personally run in a 80s 500sec with 90k on the clock? I usually use generic no-brand 15w30 oil for most of my classic cars, but they are like from the 60s or older, need oil changes really often and use stone-age engines. It don't matter what you put in them, its barely gonna get dirty before you change it anyways.

This merc is different tho. It's a much newer classic, uses a engine that's a few generations forward of all that stuff and much more sophisticated.

I was going to use castrol gtx, maybe 15w40 flavor, but I thought id look at the oil table first. So I did and saw that, now im confused. What do you guys recommend?

 

[hotrodder]

That table is only about viscosity and like you say everything overlaps to the point where it's pretty much meaningless unless you live in the desert etc. The bits that matter are the ACEA/API specs and manufacturer approvals, in this case probably mb229.1 It's pretty basic stuff these days but quality and price do still vary a chunk. Castrol, great marketing but someone has to pay for that...

Personally i use Fuchs titan syn or whatever it's called now but recently noticed that Petronas have a mb229.1 oil (Euro Car Parts were flogging it cheap a while back, their 'sister' company carparts4less still is) so might use that next time if it works out cheaper. Both are a 10w40 semi synthetic

 

[Somebody]

So do I basically buy anything that's MB229.1 approved and use that? Would using a more generic oil (like Castrol GTX, which I have like 20 liters of already) be a bad thing? Do these engines have something really specific about them which only oils with mb229.1 rating cater for?

 

[Pitts Pilot]

What does your local MB Main Dealer have by the 50 gallon drum in their workshop?

I suspect a fully synthetic oil would be the way to go.

Incidentally, I do "half service interval" oil & filter changes. It's probably very OCD of me, but as an oil approaches the end of its service/design life it's ability to lubricate and carry away contaminates drops significantly.

As a rule of thumb, you could say that 90% of engine wear occurs during the last 10% of the oil's life.

So a change at half distance, for a insignificant cost at your local non MB garage - I take them the oil and a genuine MB oil filter, so when the car is back on a MB dealer's ramp, everything looks cosher- makes long term sense, and may prolong the life of the engine?

Just one school of thought amongst many

Cheers,
Robert

 

[Somebody]

I also over-maintain my cars a lot, on my daily driver I change the oil/filters every 3k miles instead of 5k, because its lasted waaaay longer than anybody back then would have imagined it lasting, and so far its been healthy so I want to keep it that way. Oil aint expensive compared to engines. That's why I am also changing EVERYTHING in this car, to make sure its all tip top.

I try to do all my own servicing and stuff, keeps me sane and takes my mind off my job, so I usually do it all myself.

As it happens, I just looked and 15w40 castrol gtx is actually in the mercedes approved list, I didn't notice it before. So I guess that's that. Or any other oil in that list?

What about viscosity? I guess basically reading that table, anything will work. I might use 15w40gtx then just because I have it already.

 

[grober]

I would use a GOOD semisynthetic 10w40

Fuchs TITAN SYN MC 10w-40 High Performance Semi-Synthetic Engine Oil (formerly Fuchs Titan XTR) - 5 Litres
£20.21
or
Millers EE SEMI SYNTHETIC 10w40
Engine Oil | Semi Synthetic Oil | EE SEMI SYNTHETIC 10w40

Castrol GTX is overated and expensive especially if they are still doing the 4 litres for the price of 5litre containers!

 

[Rory]

Doesn't that table basically mean ''as long as you live on planet earth, and not in Siberia or the Sahara desert, use pretty much anything''?

I can't see any other way to interpret it.

I mean, it shows pretty much every single oil in common usage being suitable for pretty much every temperature range ever.

Or am I just reading it wrong?

Nope - that's how I interpret it too. MB's are not "oil sensitive". I even think the MB229.xx is nothing more than marketing hype and would be happy to use any "quality" oil even if it didn't carry the approval.

 

[johnsco]

I would use a GOOD semisynthetic 10w40

Fuchs TITAN SYN MC 10w-40 High Performance Semi-Synthetic Engine Oil (formerly Fuchs Titan XTR) - 5 Litres
£20.21
or
Millers EE SEMI SYNTHETIC 10w40
Engine Oil | Semi Synthetic Oil | EE SEMI SYNTHETIC 10w40

Castrol GTX is overated and expensive especially if they are still doing the 4 litres for the price of 5litre containers!

And I agree.
Do not use a fully-synth on an engine of this age.
A good semi-synth gives you the best of all worlds.
Personally - I use Millers.

 

[Rory]

As a rule of thumb, you could say that 90% of engine wear occurs during the last 10% of the oil's life.

Is that your own thought, or is there some research to support it?

I've seen stuff from the US, where they take oil analysis very seriously, that suggests new oil causes more wear, then it settles down, then increases again. So changing your oil too often could be a bad thing!

 

[Terry_]

For 116 and 117 engines a 15w40 is absolutely fine.