Hi
I have a 2008 Grand Cherokee with the Merc OM642 Diesel unit in it. I have no DPF fitted, Jeep only fitted them on new model in UK I believe.
My oil spec is 229.51.Will I be ok using any Oil that is Merc approved to 229.51 or is it not as simple as that?
I am looking for ultimate Engine and Turbo protection rather then fuel economy.

What are the ingredients in the oil I should be looking for? Indeed are all 229.51 oils made to the same 'recipe'?

Any suggestions on viscosity range? My handbook calls for a 5w-30. The UK has a relatively moderate climate.

Forgive me if any of my questions are a little naïve but I am just learning and am finding the subject very interesting.

Many thanks.
Tikka.

229.51 has been superseded by 229.52.
Yes any oil with 229.52 certifications will be fine.
Also, 5W-30 would be fine for England.
I had over a hundred OM642s non-DPF in my Sprinter fleet. As well, I recommend only using OE MB oil filters for the engine.
Friend of mine had the exact same JGC as you have. Traded it in as local Jeep dealer was clueless on how to maintain the truck.

Any MB 229.51 would do, and it's more likely to be an xW40 in my country.

Hi Danno
Thanks for helping.
I noticed the 229.52 spec but I wonder when the specs move on for different engines whether they start removing ingredients that may be good for my older engine. Maybe I am over thinking this?

Yes I will only use genuine filters. I read the long thread about these filters on the oil filter section of the forum.

At the moment my Jeep is getting PETRONAS Syntium 5w-30 as fitted by Jeep Dealer.

Diesel Jeeps are by far the most common in UK. Petro ones are rare due to our very high taxes on fuel.

Hi Zeng
Thanks for you help.
I am guessing you guys use a 40 weight due to your hot climate?

229.52 covers 229.51 spec so you're good to use it.
I know MB extended OCI with the launch of 229.52, so you shouldn't have worries.

I believe 229.52 is identical to 229.51, with the exception of a more stringent fuel economy test. I would stick with 229.51. More options.

MB 229.52 is more stringent than 229.51 in areas of oxidative thickening and fuel economy, and is otherwise the same, according to Lubrizol. Mobil 1 0W-30 ESP meets MB 229.52.
https://online.lubrizol.com/relperftool/pc.html

If you’re looking for the ultimate in engine and turbo protection, then a Low-Mid SAPS oil isn’t the best choice. I think you probably want the additional AW additives an E7 or E9 synthetic Diesel engine oil. E7 or E9 in 5w30 or 5w40 would be the lube for you.

I have a OM648 CDI with DPF. To protect the DPF I use MB 229.31 or MB 229.51 which is usually Mobil Delvac 1 ESP. I tend to worry more about DPF.

Since when Mobil1 Delvac ESP carries MB 229.31 or .51?

Yes, I'd access to Total Quartz Ineo MC3 5W40 MB 229.51 C3.

Not PETRONAS I see. Any particular reason as I presume it is readily available?

Hi
Would a 228.51 spec suit my needs better? If I am reading things correctly 228.51 seems to be a diesel specific spec.
According to Mercedes this spec is ok on the om642 without dpf.
https://bevo.mercedes-benz.com/d/d/en/Spec_223_2.pdf
They seem to be a more Truck and commercial vehicle oil. Although still low saps.

Hi
I do not have dpf so I hope I have a little more wriggle room with lube choice