0W vs 5W oil in OM-642

bigb

2011 Winnebago Via 25Q on 2010 3500 Tucson, AZ
Why are a lot of brands of 5W-30 going away in favor of 0W-30 and what are you using in your OM-642?
 

220629

Well-known member
My opinion would be that the 0w-30 viscosity oils are probably getting popular with many manufacturers for the better miniscule (in my opinion) theoretical mpg increase it gives. Vehicle manufacturers are trying to squeeze everything that they can to meet emissions regulations. As that results in more specifications for 0w-xx viscosity oils the use/market share of the 5w-xx viscosity products will decrease.

vic
 

dharmasprint

Well-known member
0W oils also have a better cold temperature initial flow point, so what's not to like?

The upper viscosity number has more of an influence on fuel economy such that lots of gasoline engines are now using 0W20 as the spec oil viscosity. What the manufacturers don't notify the owner of is that you are going to need to top up the oil every 1000kms by a litre.

This hasn't been my experience with my Sprinter using 0W30 though, with an OCI of 15000 km and lots of highway. I lose maybe a 1/4 litre due to oil pan leaks instead.....
 

4wheeldog

2018 144" Tall Revel
Yes they do but as I live in the Southwest desert I'm wondering if 5W would be better.
At least with Mobil 1 ESP, the 0W oil is slightly thicker when hot than the 5W oil. I also reside in the SW, and I use 0W/30 ESP.
 

bigb

2011 Winnebago Via 25Q on 2010 3500 Tucson, AZ
At least with Mobil 1 ESP, the 0W oil is slightly thicker when hot than the 5W oil. I also reside in the SW, and I use 0W/30 ESP.
That's what's in there now from Schumacher MB in Scottsdale where the PO had it serviced, maybe I'll stick with that. Although I was considering Motul 5W-30.
 

CJPJ

2008 3500 170 EXTD 3.0 V6 OM642.993 4.182
And how they make it thicker.. add curled when hot molecules. So a OW/ Oil has higher % of the curlies
. Where straight a 30w oil doesn’t have any curlies.
You know curlies get chewed up in a engine with mileage, which thins out the oil.
.. it’s best to use the oil that closest matches the conditions.
 

220629

Well-known member
I've always been concerned that the manufacturers of vehicle fluids don't have a clue as to what they are producing and that the tests that MB has developed to verify fluid applications for their engines are substandard. :dripsarcasm: :dripsarcasm:

I'm so concerned that I actually go off list to use some products that aren't even approved by Mercedes for my vehicle.

If cost is not a concern, I really do believe that an owner can't go wrong using the products that are recommended and approved by Mercedes and listed on BeVo.

I do use the MB and ACEA specs as a guide for my off list cost saving selections.

vic
 

OrioN

2008 2500 170" EXT
I've always been concerned that the manufacturers of vehicle fluids don't have a clue as to what they are producing and that the tests that MB has developed to verify fluid applications for their engines are substandard. :dripsarcasm: :dripsarcasm:

I'm so concerned that I actually go off list to use some products that aren't even approved by Mercedes for my vehicle.

If cost is not a concern, I really do believe that an owner can't go wrong using the products that are recommended and approved by Mercedes and listed on BeVo.

I do use the MB and ACEA specs as a guide for my off list cost saving selections.

vic
Yep, oil is....... oil
 

4wheeldog

2018 144" Tall Revel
And how they make it thicker.. add curled when hot molecules. So a OW/ Oil has higher % of the curlies
. Where straight a 30w oil doesn’t have any curlies.
You know curlies get chewed up in a engine with mileage, which thins out the oil.
.. it’s best to use the oil that closest matches the conditions.
Or, in synthetics, it can be the base stock has superior characteristics. It certainly doesn’t seem to lose viscosity (Or gain it).
 

showkey

Well-known member
It’s been over 20-30 years now since the Japanese and others went from 10w-40 to 10w-30 to 5w-30 to 5w-20 to 0w-20…….over that history the world was ending as we knew ………but………we and the engines and the oil specs are still here. Most of the changes were backward compatible.

0w-16 is the latest step down. It’s all about pumping losses. Same reason for electric water pumps, electric power steering, low friction piston and rings.

As far as bearing clearance changed over time the Japanese ran .0008“ main and rod clearance when it was 10w-40 and 0w-20 oil. Those engines ran 5000-8000 red line.
 

Wrinkledpants

2017 144WB 4x4
I have virgin oil analysis results for M1 0W30 and MB 5w30.

The 0w30 is thicker cold and hot, and it’s got a beefier additives pack with more anti-wear additives. I assume the MB branded oil is actually M1, and if so, the 5w30 appears to be inferior.

I am nearing the end of my 10k run on the MB branded stuff to compare wear metals against the 0W30 run. Even still, I have no plans to go back to the 5W30.
 

bigb

2011 Winnebago Via 25Q on 2010 3500 Tucson, AZ
I have virgin oil analysis results for M1 0W30 and MB 5w30.

The 0w30 is thicker cold and hot, and it’s got a beefier additives pack with more anti-wear additives. I assume the MB branded oil is actually M1, and if so, the 5w30 appears to be inferior.

I am nearing the end of my 10k run on the MB branded stuff to compare wear metals against the 0W30 run. Even still, I have no plans to go back to the 5W30.
Very useful input, thank you.
 

Rocksnsalt

There Can Be Only ONE
My understanding has always been 0w-30 or 5w-30
are supposed to flow better at low temps so as to provide better lubrication at start up compared to 10w-30, that’s it.
When the operating temp is reached it flows and lubricates like 30w.
Theoretically, by virtue of the better cold temp lubricity 0 and 5w provide, they may also help with easier cold cranking as in mfg’s can go with a smaller battery, smaller wire etc saving cost and weight…
the latter of which can contribute to improved mpg when many things in the mfg process is done with that in mind.
 
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dharmasprint

Well-known member
0W oil is useful if you live where the temperature goes down to -30 or colder. While 5W is rated to -30, it's still kind of thick even with a block heater. I've tried 0W40 for winter use but find it behaves more like a 5W or 10W when the temperature gets below -30.
 

4wheeldog

2018 144" Tall Revel
0W oil is useful if you live where the temperature goes down to -30 or colder. While 5W is rated to -30, it's still kind of thick even with a block heater. I've tried 0W40 for winter use but find it behaves more like a 5W or 10W when the temperature gets below -30.
Personally I would not start an engine below -30 without preheating.
 

dm07

Active member
I would follow the MB viscosity chart above. Since I live in a colder climate I run 0-40 in the winter, 5-40 if the dealer changes it during the warm months.

The old rule was to run the thickest oil that will crank...I know from experience that 20W oil is very unhappy at 20 degrees F
 

4wheeldog

2018 144" Tall Revel
Agreed, however not many vehicles seem to have preheaters these days and finding aftermarket units seems to be getting more challenging day by day. Do whatever works for you.
How about I just live my life in such a way that I never need to start and engine (Or get out of bed) when it is -30 or less?
I did when I had to when I was younger. Not anymore.
 

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