[smart_guy]

Dear All:

I'm a little convinced that the reason many MB engines die quick where I live is because of the law rating thermostats widely used. Some even use 65c thermos.

This thought can be really affected with the answer I'm looking for.

W140 and MB's of the same generation, and older, have many different t-stat ratings. I've seen 60c, 65c, 71c, 79c, 82c and 87c so far.

I used 65c for the first year I owned my w124 and noticed that coolant temps go almost as low as around 65c in coolest conditions and like 110c in worst conditions. When I replaced it with the 87c, it never went below what seems to be 85c, but on the other hand never ever went above 100c (well, the first couple of weeks it went a little over 100c but then never again, dunno why). I had to adjust the aux fans to always run low speed, but with a plug to disconnect at well, and I do that in winter, and the high speed with the AC, just to be on the safe side and feel psychologically better, or at 105c. Been like this for the last 2 years. I also noticed improved performance and fuel economy. Before that it was low speed with AC and high speed on 85c, which really consumed the aux fans.

Sorry for the long introduction, and the weird subject title . The question is; do MB's newer than W140, and those of same generation, have different thermostats available as well? or are they universal now? MB's like W220, that is.

Thank you in advance.

 

[Kajtek1]

Don't think MB ever sold thermostat set to 60's or 70's.
The settings vary slightly between engine models, but it oscillate in 78-83C from what I have seen.
What coolant do you use?
I become religious about using MB coolant and my diesels run with engine fans removed even above 100F outside.

 

[smart_guy]

Yup, I second that MB does not sell or even approve of those lower ones. I even asked the local dealer here and that was the answer.

The problem is, Beher, an approved maker for thermostats by MB, makes these lower ones. Dunno why as of yet. I'm certain that these are not meant for appropriately running engines. Maybe they have their own special out of the ordinary use?

And also as far as I can tell, each engine type has only a single approved thermostat rating.

Now, if W220 for instance, uses a different t-stat shape used on older models, then it most likely does not have lower rated ones made by the MB approved manufacturer. If this point is proven, then my original hypothesis is as well.

The coolant I use is the genuine MB coolant + distilled water, respectively in a ~40% to ~60% ratio. At temps higher than 100F I also can run my car's engine without aux fans provided that no AC is used. But the thing is, how much higher than 100F? Summer here could get to as high as 120F. In some exceptional days it could go over 122F. You think you can still do it with such temperatures?