On the bevo sheets, there's only one MB fluid that meets spec, no other fluids are listed.

https://bevo.mercedes-benz.com/bevol...ets-sort1.html

I could have sworn I saw a sheet with compatible fluids listed.

It was a few years ago.

Mercedes makes it simple by running and updating their site with approved fluid listed.
It is the owners who want to cut the corners that make it complicated
Beware that we live in times when technology changes on monthly basis, so what was approved years ago, very often doesn't apply anymore.
The motor oil recommendation for my Bluetec changed 3 or 4 times in car 10 years of life.
So read the sheet before each service.

I wonder if the recommendation actually changed, or they found issues with mixing fluids?

More to a specific point on whether one should use the spec'd fluid or not, especially in an SBC system: Will Mercedes honor the extended warranty on the system if they discover a non spec fluid was introduced?
I'll stay with what the manufacturer specs, thanks. Even $30/liter isn't much compared to the replacement cost of the pump.

Are you a historian?
Mixing fluids is never recommended, but sometimes it is allowed.
We had the topic about mixing coolants when MB switched from pee color to blue one.
Took me whole net search to track a letter from MB USA headquarters saying they are comparable.
Than again, why risk it cutting the corners for $5 savings?
When I have time - I order fluids on the net and usually MB fluids come cheaper than "cheap" stuff my local suppliers sell.
Than when I am in hurry, I just pay local MB dealer what they ask. How much hassle you are ready to take for $5 or even $10 savings?

Cutting corners is an opinion.

331 spec sheet isn't very helpful.
Shows only compatible with 0009890807 which is a standard 'Super" Dot 4 fluid.

There have been multiple revisions since then, with the latest PN# replacing the older ones is now a Dot 4 LV.

MB fluid isn't magically different than the rest; there are many good brake fluids like pentosin that are good alternatives; they are not 'lesser'.
MB doesn't make fluid, they outsource it from others.

Also with the latest part number being a Dot 4 LV, that proves my point that 5.1 is compatible; it's a superior spec with more stringent requirements.
Lastly, brake fluids 4, 4+ super, 4 LV, 5.1 are all formulated with the same substances, just different ratios.

The assumption that using one that's not MB labeled is going to blow up a system is incorrect.
There is no problem with using high quality alternatives.

Of course I'm not saying go buy walmart branded brake fluid or whatever but pentosin, ravenol, etc are good for these cars.






It would be impossible for them to tell since all compatible brake fluids are formulated with the same materials.

In general I agree, but if you pull the MSDS on different brand brake fluids, you will see they are all the same base chemistry, but have different additives.

Is the mixing of the minor additives that affect the long term suitability.

That is why I was guessing that MB may have dropped the other brands, not that the fluid was inferior, or incompatible, just that for long term use they did not want mixed fluids.

This is a bigger issue with coolants, as the additives are for long term corrosion protection.

I assume that any mixture reverts to the shortest life.

When I first bought Pentosin Super dot 4 a few years ago, there was no LV option. They just introduced that a couple years ago. So as the car already has Super Dot 4 in it, I'm not going to switch to LV. LV and regular super dot 4 are two different specs. So a little confused. MB never had a list of approved dot 4 brake fluids in their bevo sheets, at least not in the last few years.

I might be misremembering, but I was pretty sure I saw ATE DOT4LV on it when I got our 2007 W211 in 2010.
That is what I have been using since.

It may be instructive to know that Pentosin do not list MB as an approving manufacturer in their DOT4LV spec sheet, although they (sorta, kinda) do for their Super DOT4 spec sheet.

In addition, MB themselves, via sheet 331.0 that was updated on March 25th, 2019, indicated that any brake fluid with reference number 000 989 08 07 is acceptable. Only Pentosin Super DOT4 is cross-referenced to this number.

Hey Mate,
I have been running Penrite 5.1 fluid in my C250 for the last 3 years (120km) with no issues.

Most modern MB use Dot4LV (Low Viscosity)
DOT 5.1 should be OK< with a change.
I wouldn't mix fluids.