francia417

Which weight full synthetic MB 229.5 spec oil should I use for long term durability of my GLC?

larrypmyers

Your Operator's Manual contains a graph that provides answers to your question.

I use Mobil One 5W40 in my GLC.

madelko

Mobil One 5W40

DanD.

it's not just Mobil One 5W40 it's Mobil 1™ Formula M
https://mobiloil.com/en/motor-oils/m...ormula-m#5W-40
approved by Mercedes Benz MB-229.3 and 229.5 specifications

Camaroguy72

I'm using the Amsoil European 5W-40 (229.5)

https://bevo.mercedes-benz.com/bevolisten/229.5_en.html

from Amsoil:
Viscosities:
All TEMPS....0W-30, 0W-40
Above -13 F .5W-30, 5W-40, 5W-50
Above -4 F .10W-30, 10W-40, 10W-50, 10W-60
Above 5 F .15W-30, 15W-40, 15W-50
Above 23 F .20W-40, 20W-50
Capacities: Base, With filter 7.4 quarts After refill check oil level.
4MATIC, With filter 6.9 quarts After refill check oil level.
Torques: Oil Drain Plug...30 ft/lbs

Mercedes allows higher viscosity recommendations in western Europe (10W-40), so depends where you're located.
https://bevo.mercedes-benz.com/d/d/en/spec_223_2.pdf

Xbowguy

I'm using Mobile 1 European formula 0-40 Costco quarts when on sale.. or Wally world 5 qt jug 24.95

DanD.

24.95 cheap price for 229.5 spec. Are you sure the oil you buy meet MB requirements?
Personally, the cheapest 5L jug I was able to find was 39.99.

tisi_03

Liqui Moly 2041 5w40

Camaroguy72

I used to be a mobil 1 guy until it was the only oil ever ran in one of my old cars and after 110k miles the engine started just leaking out of all the seals. I hoped for better seal conditioning and longevity .. now I get Amsoil for $9.80 / qt for 5W-40. Been using it on the cars and bikes for years and always pleased with how the car runs and no mystery leaks

Xbowguy

Since we're on the subject of oil... on my previous ML350 I didn't wait til the 10k miles... I've been changing my own oil on or around 7500 miles using Mobile 1 0-40 and Mann filters How long do you guys wait til you change your oil and filter?

Camaroguy72

im doing them every 5-6k with amsoil European 5w-40 (warm climate in the southeast ). I worry about the oil separator and pcv system degrading and being an expensive repair , hence the cheap insurance for the direct injection engine. Heard horror stories on oil separator replacement cost.

DanD.

I had to use lab to find the optimal interval based on the results, with ML350 BT I had to get down to 3.5K miles interval to get iron numbers where they should be, even know TBN were high, I just did my first oil change with GLC after 4.5K and sample on it's way.
But I think for gas cars 5K is the good mark.

fred9x

Dan D, please let us know the lab results.

Thanks

DanD.

Just got report back from the lab. I used Liqui Moly 5W40 oil, sample was done at 4300 miles on the oil. Im very happy with the results. Im thinking to run the next oil for 5.5 or 6K,
TBN 7.3 is very high for 4.3K miles, Im sure it can last another 1-1.5K miles.

Lab comments:
" This young Mercedes looks great at just over 10,000 miles. The first look at internal engine
wear shows oil-sharing parts in good health, since metals are all at or below the universal average levels.
Those show typical wear for the 2.0L turbo engine after ~7,400 miles of oil use. Your oil wasn't run for quite
as long, so it makes sense that iron would be a little lower (it tends to track most with oil use). Other metals
are close to averages, and that's fine. No contamination is present, and the 7.3 TBN shows the oil still had
active additive left at the time of sampling. "

fred9x

Thank you Dan.
I have had tested only a couple of used oil samples from prior vehicles and am NOT an expert. But my 2005 Toyota Highlander at 86,000 total miles and 9,500 mile on the oil tested out with a TBN of 2.1. Blackstone Labs comments ended with suggesting I go out to 11,000 mile oil change interval. (I went back to my usual 7,500. :-)

DanD.

TBN is not the only one measurement, Like I said before with ML, TBN number was around 3 but iron was above average with MB oil, I was afraid to use any other oil in diesel.

In this results Iron is 9 and AVG is 14 so probably another 1K will get me close to AVG. and they stated AVG numbers based on 7.5K miles, the same interval as you did.

Next oil in my car will be
Liqui Moly 20232 Molygen New Generation 5W40, and after two runs will do another sample. This new generation oil has a very high reviews.