My 300E never reaches 80C when on the highway - PeachParts Mercedes-Benz Forum

tjts1 · #1 06-24-2010, 12:18 PM

Running at 79c doesn't make a whole lot of difference to be honest. I'm getting the same ~30mpg on the highway with a 79c thermostat that I did with a 87c thermostat. Last tank was 32.5mpg. I did notice that it pings less on 87 octane under high load than it did with the 87c. Mercedes used a hot thermostat to reduce emissions, not for fuel economy. I would keep the cold thermostat.

glpro160 · #2 06-24-2010, 12:27 PM

Quote:

Originally Posted by tjts1

Running at 79c doesn't make a whole lot of difference to be honest. I'm getting the same ~30mpg on the highway with a 79c thermostat that I did with a 87c thermostat. Last tank was 32.5mpg. I did notice that it pings less on 87 octane under high load than it did with the 87c. Mercedes used a hot thermostat to reduce emissions, not for fuel economy. I would keep the cold thermostat.

What about engine wear? How much does it do with the engine wear?

What W124 are you running? The best I ever got is 24mgp.