My (limited) thoughts on Unimog engine oil
As I am looking to change the oil in my mog, I decided to revisit what oil I use (Shell Rotella T4 15W-40). I found this post I started on Benzworld from a few years ago that shows how I ended up where I did. The full thread can be found here:
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Okay, I know I am kicking a hornets nest here and it has been covered a ton already but I still have questions about which oils to use in my truck. I will start with engine oil.
- I am looking for general purpose oil for a variety of conditions. I guess you could say the broadest capability for world travel. Alaska to Argentina – or more locally… Palm Springs to Ourey.
- This is for a U1300L with an OM352A engine (with turbo). But I guess according to the owners manual, this will also apply to the U1700L
- I have zero allegiance to any brand. I just want to know what I should buy and not have to worry that I am destroying my expensive toy. Something easily available would be preferred and cheaper the better.
Other relevant threads:
https://www.benzworld.org/threads/oils-and-lubricants-for-unimog-1550-1992.1711741
https://www.benzworld.org/threads/unimog-oil-type.2858521/#post-16336209
https://www.benzworld.org/threads/engine-oil-comparison.1330768/#post-2472382
My journey:
So, I will start with the manual. According to first page I should be using “10W, 20, 30”. But, since I have Turbo I should use “S-3 quality” and refer to product sheets “227.0/227.1/228.1”.
According to this chart, 15W-40 seems to be the broadest temp range. Starts with 15 weight and after warming, runs with 40 weight. I am guessing though that the shaded viscosities are preferred as they are the ones listed on the previous page – “10W, 20, 30.”
Then I went to the MB specs site – engine oil:
https://operatingfluids.mercedes-benz-trucks.com/category/engine-oil/en
I do not see 227.0 or 227.1. So lets try 228.1H – I assume t he H is for “historical”. This is a short list. Only 15W-40 and 20W-50 are listed:
https://operatingfluids.mercedes-benz-trucks.com/sheet/228.1H/en
At the top of this sheet it says “For use in vehicles/engines refer to Sheet 223.3”. I checked out 223.3 where there is no mention of OM352 or OM366 engines at all:
https://operatingfluids.mercedes-benz-trucks.com/category/engine-oil/en
Back to 228.1H. At the top it also says “NOTE: Publication of this sheet will cease on 01.07.2022. Please use as an alternative 228.3 or 228.5 products.”
I went to 228.3 where there were a ton more options. Products in 10W-30, 10-40, 15W40, and 20W-50 viscosity. Most products are in the 15W-40 category:
https://operatingfluids.mercedes-benz-trucks.com/sheet/228.3/en
I also checked out 228.5. Here are products for 5W-30, 5W-40, 10W-30, and 10W-40. Most products are in 10W-40 category.
https://operatingfluids.mercedes-benz-trucks.com/sheet/228.5/en
Questions:
- Can we pull from list 228.3 and 228.5 or should we stick to the historical 228.1H?
- I am guessing, even though it is not represented in the owners manual chart, that 5W-40 would be the ultimate in flexibility, right? In which case “Mobil Delvac 1” would be the only option.
- I do have a ton of Shell “Rotella” T4 15W-40 in my garage that I use in my Montero. Shell “Rimula” 15W-40 is on the 228.3 approved list. Is “Rotella” and “Rimula” the same thing? Second, would I be safe with 15W-40 or would that or would it be a problem in really cold temps?
- I see nothing about “S-3” anywhere other than the owners manual.
Something that caught my eye was when @unirover posted in one of those other threads “stick to the specs and quantities by the manufacture”. That is really what I was trying to get to with this process.
So krietpiel, are you thinking MB has not taken the Zinc thing into consideration with their list? The 228.1H list was last updated on 07/23/2022. Although it doesn’t really matter, I cannot find a single one of those products here to buy.
That article is interesting and mentioned using “CI-4”, and if not found, then “CJ-4”. This is the back of the Shell bottle. Not pushing this – it’s just the only thing I have in front of me.
Conclusion:
I am just going to keep using Shell Rotella T4 15W-40. Why?
- I have been using this oil for years and everything seems to be fine. This is an extremely weak argument though and I usually don’t put much stock in it when I get it from someone else. How can I evaluate this? My engine didn’t blow up? That is a pretty low bar. I think without lab tests, this is a useless statement.
- Because that is what I use in my Montero, so I already have a lot of it on hand. It is nice only having to buy one oil for all vehicles.
- It was the closest thing I could find to actually being on the Mercedes list.
- I cannot come up with a better answer after reading all of this stuff again. Basically, I will need more evidence to change and I am tired of looking into this. I have a huge list…
Some random points:
- George Bull (Unimog Center) did recommend, at some point, using 5W-40 – This might have been after I had such a hard time starting the truck in sub-zero temperatures in Washington. So, according to my research above, Mobil Delvac 1 would be the way to go because it is on the Mercedes list.
- Castrol seems to be the drug of choice in Germany and Australia. I could not find any of Castrol oils on the Mercedes list here in the states.
- When I was at Terry Lee Enterprises, I asked Rob what he uses on all of his trucks and I cannot remember now. I think it was either Mobile Delvac or Chevron Delo. I do know it was not Shell, Amsoil, Valvoline, Castrol, Lucas, or Penzoil.
- I have contemplated getting the Kirkland stuff from Costco. I do like saving money. Maybe I should look into who their manufacturer is…
I am totally open to discussion and feedback on this topic. Post comments below.
