When I took the car in for service A, the invoice showed that the dealer had put in 8 quarts of oil, yet when I used the procedure to check the oil level - as already shown on this board - it showed an oil level of 7.5 quarts. No big deal.

When I took the car in for service B, the invoice showed that the dealer had put in 9 quarts of oil?! I thought the C320 only took 8 quarts. Anyway, after checking the oil level, it showed a level of 7.1 quarts. So my question is, what's going on with this dealer? He must be scamming somebody.

 

Seems like the dealer scamming MBUSA. I'm sure they get reimbursed for scheduled maintenance, so a quart here and there will add up. That, or the oil guy is really sloppy

 

From what I've read on here, the dealer shorting a quart on the oil change isn't terribly uncommon.

 

The dealer doesn't open individual cans of oil and therefore doesn't track exactly what they use. Yes, the industrial oil dispenser tracks how much oil is dispensed, but the technician has to remember the amount and enter it on the worksheet. Sometimes they get it right, othertimes they don't. Sometimes they have a bad habit of relying on what another tech says is the correct amount, etc.

The V6 sedans hold 8 quarts. If you get a reading of 7.5 or higher you're good to go. If you're too close to 8, you can get a fault message on a hot day in stop-n-go traffic, directing you to remove some oil. (I have.) Certainly if you are over 8 quarts, you should get the fault message.

My owner's manual says the car takes 9 quarts, but it never has. Maybe that's why the tech said he put in 9 quarts, though.

 

dyno mode displays an exact quantity ( to the 10th) of oil in the sump.

 

And my experience is that the oil amount readout will VARY WIDELY based on several factors: outside temp, engine temp, how long the engine has been shut down [how long the oil has had to drain completely into the sump], and how level the car is. Variations on the same day have been as much as 1.0 qts on my car. This system is hardly the basis for deciding if a dealer is "cheating" anybody.

And I agree with the observation above: different techs use different standards about how important the exact amount of oil put in the car is when it comes to the documentation. Unless you are getting a reading under 7 qts right after an oil change, on perfectly level ground, after the car has been shut down for at least an hour....then motor on...

 

Actually the car holds about 8 liters which is equal to about 8.5 quarts. In the dyno setup it really doesn't change numbers when you change country codes. It only switches the designator. In addition I caught my dealer with the same and made him add some. The next day I used dyno and got a reading of 8.3 qts. I have as yet to get the malfunction light and I do periodically check it that way and it is still above 8.2 qts. The dyno is accurate to +/- 0.1

 

You have to relize that the oil filter holds about 0.5 to 1.0 qts of oil.

C class V6's take 7.9 qts of oil.

Brian