NYCGLK

I did my first oil analysis on my GLK. My car has over 48k miles and 10.6k miles on this oil. I only did scheduled oil changes about every 10k miles using whatever dealer put in (M1 5W40 according to invoice). This time I did my own oil change and took a sample to send to Blackstone.

Here is what Blackstone had to say:
Universal averages in the far right column show typical results for this type of engine after about 7,500 miles on the oil. You've gone a bit longer than that on your oil, so it's not too surprising to find some higher-than-average metals. In particular, iron will track directly with miles on the oil, so we expected that to read a bit high after 10,600 miles on the oil (and it did). No fuel or coolant contamination was found, and the viscosity read right on target for Mobil 1 5W/40. This first sample from your Mercedes looks good; be sure to check back to build wear trends.

I put in M1 0W-40 and will do oil change a bit earlier (7500 miles) to see the difference in iron count. Also, I removed the plug, which may meant that there was more iron in the pan, as dealers usually use suction method, which may leave some particles behind. So this could have been accumulation after 5 years.

mikedr

Fascinating! I used to do this sort of thing many years ago with a Saab I owned. I realized that for me -- trading in a car after 2-4 years -- just abiding by the manufacturer suggestions was more than sufficient. I could see how if you plan on keeping the car till it dies, that this would be valuable though -- presumably, keeping on top of the actual oil quality might give an extra X0,000 miles of engine life?

ble2716

I wonder if you'll get better result (less metal shaving) in your next oil change.
Keep us update.

bop11

It's molecules per mile for iron so if you did 3 change in 20,000 miles or 2 changes, the total would be the same if there is not a problem although the number per change would be lower in each of the three. Don't waste the resources in this vehicle by changing earlier than recommended.

NYCGLK

I hear what you saying. But fewer molecules of iron in oil would mean better lubrication. If I follow your logic why bother changing oil even at 10k miles given these results.

volkvin

For my cars, cars that i love, whether it was my first 540i or my impreza, or current GLK i follow manufacturer's recomendation/2. So with my 1995 bmw, i was changing the oil myself every 3k kms. Every single time it was black as hell, but i also drove that car into the ground. With Subaru, the service was every 10k, i did it every 5k. With GLK they recommend 15k km for first service. I will probably do it around 8-9k. And wether i will keep this car for a long time or sell it in 3 years, i try to stay within my principles

NYCGLK

as the lab test shows that's a waste of money and environment. I've only done 5 oil changes (every 10k miles since the car was new).

I know of guy who does oil changes every 15k miles on his 18 year old 911 and he has over 300k miles on it.

NYCGLK

Here is the report

volkvin

Waste of money is arguable. Environment i could not care less lol.
And yes, i have also heard of million kilometre cars as well as had a vehicle in my family that never had an oil change in span of 3 years.

Like i say, for some its lab tests, for some its money, for some MB recommendations. For me, my principles

Edit: Also, i do not see anything interesting in that report. Sorry, Yuri

NYCGLK

you wouldn't and report wasn't posted for you but to add to the tread for others who are interested...not sure why you even bother posting here, except to state your "principles" that are no more than your opinion based on zero of factual information.

bop11

The test uses a spectrometer to measure materials in the oil. This measures dissolved metals such as iron and not particulate iron. The dissolved materials show what is wearing in the engine and gives you a clue as to which component might be at risk. It is particulates that would wear the engine if in high enough concentration. However, the oil filter removes these particles and Blackstone does do a particulate test which basically show how the filter is working and any other strange particulates. In this case it is 2% (less than .6% is average) which is low so he has good filtration. The higher level of dissolved iron is not a reason to change oil early. It just proves rotating machinery wears.
The biggest problem would be reduction in viscosity and oil dilution due to fuel leak around the rings. Here again he is quite low. I think Blackstone is right on with their recommendation.