Thank you, uberwagon for your quick response! Appreciated.

 

OK, this latest oil from MBz is going to be available at the "retail" level:

http://store.avlube.com/mo1espfom5wc.html

Somebody in my area bought it earlier this week from his local Mobil dist. It was $5.50/qt.

 

I'm heading down to the dealer this aftenoon for something else. I will see what they are asking per quart as well.

 

I'm going to plagiarise a post I saw recently on a UK forum from www.opieoils.co.uk
I hope this is useful in understanding the meaning of the numbers.

I read on many forums about 0w and 5w oils being too thin.

0w-40, 5w-40, 10w-40 and 15w-40 are all the same thickness (14 centistokes) at 100degC.

Centistokes (cst) is the measure of a fluid's resistance to flow (viscosity). It is calculated in terms of the time required for a standard quantity of fluid at a certain temperature to flow through a standard orifice. The higher the value, the more viscous the fluid.

As viscosity varies with temperature, the value is meaningless unless accompanied by the temperature at which it is measured. In the case of oils, viscosity is generally reported in centistokes (cst) and usually measured at 40degC and 100degC.

So, all oils that end in 40 (sae 40) are around 14cst thickness at 100degC.

This applies to all oils that end in the same number, all oils that end in 50 (sae 50) are around 18.5cst at 100degC and all oils that end in 60 (sae 60) are around 24cst at 100degC.

With me so far?

Great!

Now, ALL oils are thicker when cold. Confused? It's true and here is a table to illustrate this.

SAE 40 (straight 40)

Temp degC.........................Viscosity (thickness)

0..........................................2579cst
20..........................................473cst
40..........................................135cst
60..........................................52.2cs t
100........................................ 14cst
120.........................................8.8cst

As you will see, there is plenty of viscosity at 0degC, in fact many times more than at 100degC and this is the problem especially in cold weather, can the oil flow quick enough to protect vital engine parts at start up. Not really!

So, given that an sae 40 is 14cst at 100degC which is adequate viscosity to protect the engine, and much thicker when cold, how can a 0w oil be too thin?

Well, it can't is the truth.

The clever part (thanks to synthetics) is that thin base oils can be used so that start up viscosity (on say a 5w-40 at 0degC) is reduced to around 800cst and this obviously gives much better flow than a monograde sae 40 (2579cst as quoted above).

So, how does this happen, well as explained at the beginning, it's all about temperature, yes a thin base oil is still thicker when cold than at 100degC but the clever stuff (due to synthetics again) is that the chemists are able to build these oils out of molecules that do not thin to less than 14cst at 100degC!

What are the parameters for our recommendations?
Well, we always talk about good cold start protection, by this we mean flow so a 5w will flow better than a 10w and so on. This is why we recommend 5w or 10w as the thickest you want to use except in exceptional circumstances. Flow is critical to protect the engine from wear!

We also talk about oil temps, mods and what the car is used for. This is related to the second number xw-(XX) as there may be issues with oil temperatures causing the oil to be too thin and therefore the possibility of metal to metal contact.

This is difficult to explain but, if for example your oil temp does not exceed 120degC at any time then a good "shear stable" sae 40 is perfectly capable of giving protection.

"Shear stability" is important here because if the oil shears it thins and that's not good!

However, if you are seeing temperatures in excess of 120degC due to mods and track use etc then there is a strong argument to using an sae 50 as it will have more viscosity at these excessive temperatures.

There are trade offs here. Thicker oils cause more friction and therefore more heat and they waste power and affect fuel consumption so it's always best to use the thinnest oil (i.e. second number) that you can get away with and still maintain oil pressure.

I hope this helps explain a bit.

Cheers

Guy.

 

I just had mine into my preferred dealer for a "B" service. They put Mobil1 10W40 in from their bulk tank, and do not sell it in quarts or liters! I emailed MBUSA and Exxon-Mobil to ask them for advice. Both replied that if I need to add oil, it should be fine to use Mobil1 0W40 (MB spec 229.5).

 

Well I was at my dealer this afternoon and they indeed were using the new M 5w40 and saying it was now "recommended" for my 2001 E320 wagon. I would strongly suggest using Uberwagon's recent post of an online seller since the dealer is selling the new stuff for over $12/qt. I think his link sells it for about $7/qt (by the case).

 

I've been using the Mobil Syn 5w40 in my car for the last two years (indy shop) and it would smoke upon start up. Not really thick smoke, but enough of a blowout to see and smell. I never liked it, but didn't think too much of it and the mechanic told me it wasn't abnormal.

I got a "oil at minimum level" warning while out and about and bought some Mobil 1 0w40 syn at pep boys. Put the whole quart in.

It stopped smoking at the very next startup. No smoke to be seen or smelled. Its been 2 weeks now and no reversion back to the smoke. I'm telling my mechanic to switch my car back to the 0w

 

I find this hard to believe since the only oil approved by AMG for since MY2005 is 0W-40 Mobile1.

All this discussion is interesting, but the Factory Approved Service Products manual from Setp 2006 says.

* Not Approved for AMG Engines

 

The recommendation to use the new 5W40 ESP in gas cars has been withdrawn and they're once again recommending the Mobil (not Mobile) 1 0W40 for the gas cars.

There were some issues with the new oil and ethanol fuels.

 

Uber when did they do that? Do you have a link for the official note?

 

Yes Uber, it would be great to get a link that shows the change. Thanks.

Also, one question, regarding "leaks" caused by Mobil 1 0w-40.

I bought E320 2001 (52K miles) from out of state. I asked my newphew who drove it down to have oil changed before start of long trip. He did it at some oil change shop, and he saw them use Mobil 1 sythetic formula bottles, but didn't see the grade. So I didn't know exactly what grade the car had in,

After about 5K, and after reading threads, I decided to change oil and use Mobil 1 0w-40, just to make sure. After about 4-6 months, I noticed a very small oil leak (one or 2 drops in my garage after I each parking).

Local shop said the oil pan and gasket were clean. But plastic tray underneath had some oil on it, and the little hole in that tray was where the oil was coming out. He thought maybe the oil was coming from the drain plug area, but was not sure 100% (saw a bit of oil there). He cleaned the whole area and the plastic tray very good, so that next time it will be more obvious.

I didn't see any oil leak untill about 4-6 weeks later I saw the oil leaking again. I realized the leak is so small that the oil was slowly accumulating in plastic tray and when it was enough to slide around, it would drip one or 2 drops out of the plastic tray hole everytime I park it.

I have since ignored it, it's been now about 4.5K miles since oil change, and the oil level has dropped only about 3 or 4 grooves on the oil measure stick plastic end (so really only slightly below the max line where it was when I filled it). So the leak is very small, but it is annoying, and I wonder whether it can be caused by Mobil 1 Synthetic 0w-40 (just guessing that when I got it, it may have had a different grade, and when I changed to 0w-40 it sort of caused some leaks). I have read some threads talking about leaks from oil pan gaskets, but those were on high mileage cars, and that is an extra parameter to deal with. Mine is now at 62K, and again the oil pan gasket is clean as new according to the mechanic who checked it.

Thanks

 

Go to your local dealer and ask what oil they're recommending today for a gas engine. I do not have the technical detail on it.

 

At no time was I discussing the unique oil needs of the AMG cars. OP has a 2001 E320.

 

I see there's still confusion around the "5W40" products offered by Mobile [SIC]. The product you purchase at Walmart, which has been around for years and is approved for MB trucks, is NOT the same oil as the new 229.51 product.

 

Walmart Mobile [SIC] 5W40:




see Wolfgang's list for applications. You'll note Mercedes Benz 228.5 approval

 

Is that pointed at me? I doubt my shop buys their oil at wall mart

 

No, @ Jon2007E63P30. He's the one that started the AMG discussion.

The oil you're using is available thru many channels. Wally's is far from the exclusive source. FWIW, it doesn't meet any of the specs required by your car. But that's another discussion

 

MBz has developed a quality standard for the gasoline and diesel autos that would serve regardless of fuel type. That standard is is given by 229.xx


It's been like this for a number of years, perhaps 10 or 12. I'm not clear why there is so much confusion, the spec was established long ago and updated as reqiured. Doesn't anybody ever bother to read the Owner's Manual and review the specifics about engine lube oil. IMO, they've made it completely fool-proof.

A new spec (229.51) was needed when the new diesels arrived that must conform to a low-SAPS formulation or the exhaust after-treatment devices will be fouled in short order. This 229.51 quality standard is supposed to be good for both gas and diesel. Some issue has shown up when 229.51 is used in cars that have ethanol mixed with gasoline. Being in a NE state, we have mandatory 10% ethanol - - I can't buy gasoline without it unless I travel out of state.

My local dealer sezs they've switched their bulk oil back to M1 0W40, and should a diesel car ever come in for service, they use 229.51 out of bottles.

The number of diesel cars being serviced at most dealerships across the USA is gonna be a tiny fraction compared to gas engine vehicles. Why would they switch their bulk oil supply to service 2 or 3% of the vehicles passing thru their service bays

I'll contact my guy again and see if he has written documentation. The last time I chatted with him this was all taking shape.

 

The difference between 0W40 and 5W40

0W for lower Temp than the 5W

otherwise both oils are the same

Mobil 1 5W40 ESP is made for MB Dealers only use.

 

OK, I've now got the bulletin from MBUSA. I don't know if I'm losing my mind, but this bulletin suggests there's yet another 5W40 product by Mobil that only meets 229.5. They refer to this oil as M1 Formula M 5W40.

later in the same bulletin:

 

This is getting even more confusing!

 

You got that straight! I find no evidence of a 229.5 Mobil oil that's 5W40.

 

 

I have been instructed to clarify that this is not a Mobil problem, but a 229.51 formulation/ethanol problem.

Any 229.51 oil, regardless of mfr, could have this unwanted build up of "snot" within the (gas) engine.

 

It sounds like this alternate 5W40 (229.5) oil isn't availabe yet, but is expected shortly.