I replaced the thermostat on my w208 CLK320 the other day, simple job and all was well, heater nice and toasty.
I was feeling a little smug and pleased with my handiwork, basking in the warm air wafting from my vents.
Today I had to drive to Heathrow, mid afternoon, plenty of time, so stuck to 70 for most of the way and as I got closer to the airport I drove even slower, tucked in behind a lorry.
Glancing at my speedo, I noticed my average MPG was 29.5 for the journey and here in lies the mystery. Before I changed the thermostat I would regularly see 32/33 MPG and on one very gentle run I even saw 38!
Surely, if the engine is running warmer it is more efficient and should therefore use less petrol?
I'm seriously considering refitting the old thermostat, which made the engine run cold
Anyone got any theories about this?
I was feeling a little smug and pleased with my handiwork, basking in the warm air wafting from my vents.
Today I had to drive to Heathrow, mid afternoon, plenty of time, so stuck to 70 for most of the way and as I got closer to the airport I drove even slower, tucked in behind a lorry.
Glancing at my speedo, I noticed my average MPG was 29.5 for the journey and here in lies the mystery. Before I changed the thermostat I would regularly see 32/33 MPG and on one very gentle run I even saw 38!
Surely, if the engine is running warmer it is more efficient and should therefore use less petrol?
I'm seriously considering refitting the old thermostat, which made the engine run cold
Anyone got any theories about this?