2001 mercedes benz ml320 -15w40 ok?

Messages
16,998
Location
Upper Midwest
Grade is nearly irrelevant with those approvals, really who cares. Every one of them that carries the actual Mercedes-Benz approval has been proven to pass the myriad of tests Mercedes-Benz requires, including wear.

The only "deal" with Mobil 1 0W-40 is that it has the approvals, certifications and licenses as listed. So do other brands and other grades.
 
Messages
505
Location
Brittany, France
Maybe it comes down to availability in north america if you want a 229.5 oil at a good price? I wanted to try a 0w40 once or twice but it is twice as expensive as 5w40, like $10/L.
 
Messages
31
Location
Barbecue, NC
Following FSS, 15w40 is probably not a good idea. That's what the dealer threw in my Mom's when bought new in 1998...and at 60k it needed new rings and a de-sludge. Since the complimentary engine refresh, it gets 229.5 oil, the fleece filter, and FSS oil changes (2 years or 18k miles max). Still great at ~290k miles. The transmission required a new $10 part somewhere well up in the transmission a couple of months ago. Needs about 1-2 quarts of engine oil added per oil change interval these days (which increases the FSS recommendation to the full 18k miles). Not bad.

I would not hesitate to use the 15w40 with a Mann filter in the summer at 5k mile intervals. But not worth the time to change the oil more than FSS suggests imo.
 
Messages
505
Location
Brittany, France
Following FSS, 15w40 is probably not a good idea. That's what the dealer threw in my Mom's when bought new in 1998...and at 60k it needed new rings and a de-sludge. Since the complimentary engine refresh, it gets 229.5 oil, the fleece filter, and FSS oil changes (2 years or 18k miles max). Still great at ~290k miles. The transmission required a new $10 part somewhere well up in the transmission a couple of months ago. Needs about 1-2 quarts of engine oil added per oil change interval these days (which increases the FSS recommendation to the full 18k miles). Not bad.

I would not hesitate to use the 15w40 with a Mann filter in the summer at 5k mile intervals. But not worth the time to change the oil more than FSS suggests imo.
What was the interval?
 
Messages
31
Location
Barbecue, NC
What was the interval?
On that vehicle (passed around between my Mom, my Dad [since deceased], to me, to my brother, my step dad), we follow the Flexible Service System (FSS). And the max interval has been 2 years or 18k miles. Usually ending up somewhere between 12k and 18k miles in the early years and closer to 10k in the past several years.

The reason the engine sludged up is because the manual didn't specify synthetic oil for the extended service intervals. It's been fine with the full FSS intervals on approved synthetics for 2 decades since the dealership re-ringed and desludged it. It was re-ringed and desludged at ~60k miles in 2001 I think, and now has about 290k miles.
 
Messages
16,998
Location
Upper Midwest
The reason the engine sludged up is because the manual didn't specify synthetic oil for the extended service intervals. It's been fine with the full FSS intervals on approved synthetics for 2 decades since the dealership re-ringed and desludged it. It was re-ringed and desludged at ~60k miles in 2001 I think, and now has about 290k miles.
It sounds more like it is because an oil was used that didn't have the proper approval.
 
Messages
5,348
Location
down in the park
In those years, what would a 15W-40 formula have looked like? Group I oil, cheap VII and a minimum of ZDDP and DI? I suspect that was the cheapest grade available
 
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