MB Marko

I figured I'd post and see what people say...

So the dealership has used 5w-40 synthetic oil on my car since 2012.

is it possible to change back to 0w-40 for my next oil change or is it not recommend?

I'm doing my first DIY Mercedes oil change next week, and just wanted to know before I go buy the oil.

I was thinking stick with the 5w-40 synthetic oil but if its better and possible to change back to the recommend Mobil 1 0w-40 synthetic oil i will do that.

Looking forward to all the responses

Kent Seaton

Once you go synthetic, stick with it. But if you are just changing viscosity, you should be fine. The only thing I would plan is a mid point oil change just to make sure you get all of the 5w out. Lots of great posts out there about oil theories. Just takes a little digging.

MB Marko

Ya i've read some of the older thread 4+ years old and they all basically lead to mixed answers.

I might change to the recommended 0w-40 and drive maybe 8000KM roughly 5000miles then do the change again.

I'm just having a hard time deciding..... is it really worth it? hahaha

dennish

No problem changing viscosities what so ever. My car has been dealer serviced since new with M1 5W-40(BTY, hard to find-the 0W-40 is plentiful)). I went with Castrol 0W-40. Either brand or viscosity is excellent. All have MB approvals.

MB Marko

did you end up doing a mid way oil change just to clear the system of the 5w-40?

0w-40 is more expensive but I'm not concerned to much about price i'd rather get whats best for the car.

michail71

LOL, that's every Internet car thread!

The 0W-40 is stupid cheap at WalMart in the US.

I did my car just after I purchased it since CarMax performed one after the dealer did one for the previous owner. I had no idea what CarMax used so I decided to just change it out. They could only say it was synthetic.

I'm thinking of doing a partial change so I can add in some liquid moly.

dennish

No, did not do midway. Both oils claim that they mix with any other oil. Tiny amount left(residual)doesn't concern me.

Funkwagen

Where are you finding the Mobil 1 5w-40 that's 229.5 approved? I can't find it anywhere..either way, Mobil 1 0w-40 has been good for me. Changing viscosity is no problem at all, as long as the oil is on the 229.5 approved oil list

MB Marko

whoops that first mobil1 was a typo but the dealer is using 5w-40 not sure what brand.

MB Marko

i'll just grab the Mobil 1 0w-40 at Walmart tomorrow, I hope they have enough of it.

Funkwagen

If not, most of the Canadian tires have 4.4L jugs for 51.99/each. Sometimes they go on sale for 31.99 each and I usually buy a couple

MB Marko

awesome thanks ill just go to both to compare prices, since there both in the white oaks area.

Rodpwnz

I just had my Service B oil change done and I believe they used 5w-30 as usual, did I goof by not going with 0w-40? Is it a noticeable difference in way the car drives? I it really that much better? I'm in California, so the temperature doesn't get too low or high.

BerndV

Mobil 1 5W-40 is a low SAPS oil that meets MB 229.51 which is their diesel oil specification. Oils meeting MB 229.51 can also be used in gasoline engines which is why dealers generally only stock the 5W-40. However, for optimum protection in gasoline engines, a full SAPS oil that meets MB 229.5 like Mobil 1 0W-40 is preferable. Mixing them when switching is inconsequential, as they are fully compatible when mixed.

edgalang

Makes total sense now. My dealer also uses 5W-40 only as well, although the last time they touched my car was for the 40k service. My 50 & 60k service was a DYI using Mobil1 0W-40.

michail71

I saw them selling M1 0W-40 at my dealer in the parts department. Surprising the price wasn't too outrageous.

Carsy

Hello Michail, I would do some research before adding additives to oil that are used in a modern MB.

Carsy

To have the best outcome & least wear, I understand it is best to use the 229.51 for diesels & 229.50 for gasoline motors as they have different high wearing points ie cams. Why not use the correct specified oil ?.If in doubt ask our resident expert Glyn Ruck.

michail71

I would encourage anyone to do so before using it. There is plenty out there including UOAs. It is a suspension of molybdenum, which has been used for a very long time for it's anti-friction properties. It is considered to be the only additive that works with no negative effects. There could be issues from using too much but that would cost a fortune to get there.

The same company also makes a ceramic based anti-friction lubricant but, according to the company, it could potentially cause issues with spark plugs in poor engines. So it has been popular in diesel engines.

It's a German company and has a history of use in German cars.

In the end, evidence shows it works and is not harmful. But is it necessary? Probably not as the engine may already outlast the car. However, we are in a thread debating 0W-40 vs 5W-40.

There is some controversy about it's effectiveness that gets debated with evidence from both side of the argument. I haven't tried it yet as I am still researching.

Bob is the Oil Guy has plenty on it as a starting point.

BerndV

The differences in required formulation have little to do with wear and everything to do with meeting diesel emissions requirements and protecting the emission control systems on diesels.

Carsy

I have been told by an expert on this forum that there is more antifriction material in the 229.5 because of the higher cam loads of a petrol engine.

Why not use the correct oil ?. Do you know more than the oil company labs ?

ghlkal

I agree, As others have said, here in the U.S., the correct Mobil 1 0W-40 is inexpensive at WalMart.


I don't understand why a dealer is putting 5W-40 in

BerndV

Did you even read my previous posts? The optimum oil for a Benz gasoline engine is one listed under MB 229.5. The only oil approved for a diesel Benz engine is one listed under under MB 229.51, although an oil meeting MB 229.51 can be used in a gasoline Benz. I'm frankly not sure what point you are making. All of my posts on this topic have suggested using M1 0W-40 as the optimum choice in a gasoline engine, and that dealerships use M1 5W-40 because they can stock one oil that can be used in both gasoline and diesel engines even though it is less than optimum in the gas engines. They are both "correct" oils for gasoline engines, but the 0W-40 will provide better protection in gasoline engines. No, I do not know more than "the oil company labs" (sic), but clearly I know a lot more about tribology than you. MB 229.51 requires a low SAPS (sulfated ash, phosphorous, sulfur) formulation to protect diesel emission systems which are damaged by a high SAPS content. However, a high SAPS oil formulation provides better wear protection. In order to compensate for the low SAPS anti-wear deficiencies, oils used in modern diesel engines include extra quantities of friction modifiers to compensate for the lower SAPS content. In addition, oils optimized for use in diesels typically have higher TBN levels to maintain engine cleanliness in the presence of the soot produced as a byproduct of diesel combustion. I have greatly over simplified what is a very complex subject, but a basic explanation of the differences between the two formulations appears to have been necessary.

Carsy

.[/QUOTE] Quote:Originally Posted by BerndV View Post

The differences in required formulation have little to do with wear and everything to do with meeting diesel emissions requirements and protecting the emission control systems on diesels.
.[/QUOTE]



Thank you, finally. The 229.5 will provided better protection for petrol engines.

I would not let a slack dealer put the 229.51 in my petrol engine.

michail71

Oil threads often end with arguments. But it seems we have come to agreement.