One important factor ( in absence of MB refusing to install a remote starter) would be the presence of an electric heater element so we won"t wait for engine to be warm to heat up the cabin. MB preowned salesperson claims W221 has electric element, delivering (almost) immediate heat. I've also read before that previous diesels had it too, as diesel really takes too long to heat. Would that be valid on the new E250bluetec?

 

Mercedes-Benz especially,carries this option already for years so could be installed on your E-Class no doubt.
Ebenspacher and Webasto are brands often used oem.
These usually run on the car fuel and can be remoted or put on a timer.

 

Thanks. I am actually curious whether the W221 S-Class or the actual E-Class diesel has a standart electric heater. I probably won't have a ny budget left for an add-on oil/gas heater. Hot sure whether it will add any value either on resale.

 

I know the W211 E320 CDI has an electric heating element and it warms the car very fast. I don't know specifically about the E250 and S450, but I have noticed that my W221 S600 gets warm almost immediately. I don't know if it has an electric heating element or not or if this is just a characteristic of the V-12.

In the W221 it is called a PTC heater booster. It can be disabled by pressing the AC Off button on the ACC.

The other heater mentioned above is not offered in the US. Some people can retrofit them. This would be good if you are in very cold climates and your car must sit outside. You can adjust the timer in the instrument cluster and schedule the car to warm up at the same time every day (from the best I understand).

If your car is in a garage it would not work since it does burn fuel (it connects to the fuel system). Not sure of the consumption vs. running the engine.

 

Thank you Polar Bear..That confirms more or less the info obtained thru MB dealer