rayrayseels

Question for the masses. I know the "which oil" discussion has been done to death, but I have had an experience with a Bosch Service Centre today (Australia) that has led me to the experts here for an answer.

I booked my car in for an A service today, and having owned the car for one year, I decided to not go back to the dealership due to an issue I had with them last time (service advisor tried telling me that the source of a small oil leak was from "near the turbos"). The car has 130,000km, so I thought I would save some money and take it somewhere else. I have been getting the annual service carried out by the pros, and I am doing my own oil change at the six month interval in between.

I turned to Bosch, as I figured they are a fairly trusted name in the Euro business, and my first red flag was when they sent me a quote including 5w30 Castrol oil, specifically Castrol Edge Professional OE-X 5w30. I called them back and indicated that I would like them to use 5w40, and they told me that wouldn't be a problem. As a result, I confirmed a booking.

Fast forward to today, dropped the car off and re-confirmed that I needed 5w40 or 0w40 oil, which was once again agreed to. A couple of hours later however, they called me to say that they do not stock that oil and that they recommend that I go with the 5w30. I was pretty pissed off on the phone, as I had booked in under the impression that they would be able to use the 40 weight oil. I reluctantly agreed in the end to go ahead with the oil change with the 5w30, having already previously checked that it met the 229.5 spec. On pickup, the service tech was adamant that this particular oil was well suited to the car, despite the Castrol website itself primarily recommending 0w40, with 5w30 being the alternative recommendation. His response to this was that the oils referred to on the website were consumer grade oils, and that the oil used was a workshop oil (I acknowledge that this is true). He gave me the number for Castrol Tech Services and recommended that I chat to them to confirm what he is saying. I intend on calling them tomorrow morning.

My biggest worry is that when it comes to the M156 engine, everything I read online points to either 0w40 or 5w40 oil recommendations. However, reading the MB 229.5 spec, there are a slew of approved 5w30 oils including the one used. Is there an actual technical document that states that only 40 weight oils should be used, as I can't seem to find anything that does state this, even though I am a long time lurker on this site and have read through most of the engine oil threads. Any help or advice would be greatly appreciated, and I apologise if this has been covered elsewhere and I have missed it.

Jasonoff

Yes, it's specified in your owners manual.

rayrayseels

Your owners manual is obviously different to mine. I checked it first, and I can't find a reference to it other than spec 229.5 and the regional viscosity recommendations.

Vpatriota

Isn't the 0w40 more suitable for all regions/ocasions, but depending on where you live (temperature/altitude/etc) you could get a slightly thicker or thinner oil? I remember reading some elder more experienced members mentioning something like that around here.

rayrayseels

The owners manual classifies Xw30 and Xw40 oils in the same category in their viscosity graph (p322). While it is a fairly widely held view that xw40 oils are best for the M156, I'm after something solid to convince me and/or put to the shop to rectify.

Vpatriota

I'm not sure this would give you all the answers but might be somehow helpful.

https://mbworld.org/forums/c63-amg-w...ed-brands.html

Jasonoff

They should all say the same thing regardless of year, it just may be on a different page. You have an M156 in your car and you can NOT use a 30weight oil in it.

From my 2010 OM

rayrayseels

Thanks for the clarification. My manual is indeed different, but I did find the fine print. Much appreciated!

I guess I'll be back at the shop tomorrow.

Mort

Here is a link to Bevo MB Sheet 223.2 Prescribed Specifications for Service Fill Engine Oils in Passenger Cars. If you go to Gasoline Engines - Worldwide (except Western Europe) - in the second row you will see M156 and the spec is 229.5, if you follow across the row. Next to it you will see Note:2.). At the bottom of the page you will see Note 2.) states: 2.) Restriction: Only SAE 0W-40 und SAE 5W-40 engine oils are allowed. There are other notes and general comments you should also read.
https://bevo.mercedes-benz.com/d/d/en/Spec_223_2.pdf

roadkillrob

Yes everyone misses this, M156 requires 229.5 spec oil and has to be 0w or 5w-40, a bunch of 5w-30 oils are 229.5 spec but not ok for the M156, I would be back demanding the right oil or my money back showing them the fine print.

skullbox15

This is one of the reasons I started doing my own service on the C63. I used the dealer on my previous AMGs and had numerous issues.

Valvestud

Official MB Oil specs for the various engines.

0W-40 or 5Ww-40 only.