C250INLA

The 10k mile interval seems long to me. On my other car, a volvo xc90, I use full synthetic every 4 to 5k miles. The xc90 forum has discussed this in detail with opinions on both sides but the consensus seems to be that the longer manufacturer interval claim, 7k miles I think, is not recommended.

With modern engines running hotter and in increasingly cramped engine compartments such as the c250, is a 10k interval absolutely advisable and proven for long term viability of the engine ( short of sending oil samples to Blackstone labs for analysis) ? Or is some shorter interval in wide use ?

edgalang

?! I've been doing the 10k change for 14 years. The key is DO NOT skimp on oil & filter quality.

spyked

M271 engine has been around for 10 years. 10k miles or 1 year is fine. Lab results show it can go further (using quality synthetic).

C250INLA

What is the recommended (Quality) oil and filter ?

95_993

When you add a few extra oil changes over the life car it's negligible. I keep cars for about 180k typically ( past two DD). If you change at 7500 instead of 10k, it's only $366 over the life of the car. (DIY=$51/change x 6 extra changes). Not too bad.

The type of oil related failure that'll show up in high mileage is valve guide wear because many of the additives like zinc have been reduced even in Mobil 1. Not sayin' that's the case with this motor as I don't have a history with it yet (only 27k miles). My last car, an Audi A4 went a good solid 180k before selling it. Changed oil every 5k w/ Mobil 1 and motor burned zero oil.

Carlos.33193

I do 5500 only because thats what i usually drive in a year. But changing your oil too often can also cause problems, synthetic oil has detergents in it so changing it too often is abrasive on the seals and gaskets. You should follow the reccomended oil change interval as per the manual and use the reccomended oil with a good quality filter.

stratman1954

My father was a chemical engineer for Mobil who helped develop Mobil 1. He always told me it was good for 20k miles or more but said the oil filter couldn't go that long. He suggested one year or 10K changes.

thenew3

My last BMW went 15k to 18k between oil changes (based on what the on board computer said was necessary). I always used Mobil 1 or BMW synthetic. Sold the car at 175k miles. Never any engine problems. Still ran as smooth and efficient on the day I sold it as the day I picked it up with 6 miles on it.

One of the independent mechanics I used to use for service was preaching 3k mile oil changes. he wanted to prove to me that the engine would be full of sludge and have compression leaks due to wear. I let him do a compression test, he found no leaks. He took the oil pan off and found it was clean.

Every other oil change I would send a sample to blackstone labs for analysis and it always came back saying the oil was good for continued use, even after 18k miles.

Since then, I just change the oil once a year, or when the car's onboard computer says its time to change. Never had any engine issues in any of my cars and I've driven over a million miles in the last 23 years.

Glyn M Ruck

10K miles is sensible & conservative.

C250INLA

I've been using the Castrol European formula on my other car but for the merc I'm not sure this is any advantage.

On the surface, one would think the euro formula version would be better but if you look on the bobistheoilguy site (http://www.bobistheoilguy.com/forums...Number=1545481), their are some differences

Glyn M Ruck

Mobil 1 0W-40 Euro Formulation has no US dilution. 229.5 is 229.5.

Other than correct additive dose base oil selection is crucial to meet 229.5. Benz has stringent HTHS requirements which directly effects cam & tappet wear. The most heavily loaded part of the engine.

Bobistheoilguy is a useful resource but you need to sort the wheat from the chaff. There is also a lot of nonsence spoken there.