Originally Posted by terracotta
My 2006 E320 CDI had a glow plug blow off around 15K - MB replaced the entire set under warranty. However I noticed an interesting thing -
My mileage typically was around 27mpg (city/hwy mixed) and now it has shot up to 30 mpg for the same conditions.
Could the glow plug replacement have made the difference or is it that the engine is sort of
breaking in around 15K and the mileage is therefore seen to go up.
It appears 30mpg is still low by comparison with what others observe on this forum. [Sure is!]
On long highway stretches cruising around 65 mph, the max I have reached is about 35 during the summer months.
So in December, 2009 you only have 15K miles on a 2006 CDI?
Things to remember about diesels, especially with the VW TDIs.
That group does not consider their motors to be completely broken-in until 50 to 60K miles.
Could our CDIs fit into that group also? If so, you've got a ways to go.
Just last month, I bought this example:
We travel about 2K per month, so it now has 111,700 miles on the odometer.
I have so far made three detailed F E checks on it, and the last one was 37.1 MPG for 463 miles.
Not computer readings mind you, but actual tank mileage figured with gallons used over miles traveled.
Maybe it helps to have over 111K miles on the motor?
See my Fuelly:
All of this so far with a stuck open thermostat, with the temperature gauge sometimes reading only
40 C. when it is cold at night on the interstate. Should be up in the low 90s C. correct?
In the winter, do not expect as good F E as you will see in the summer. Winterized fuel don't you know?
Bad thermostat and a leaking fuel injector that leaks diesel exhaust where the injector goes into the
cylinder head holpefully will be fixed tomorrow. Maybe then my F E will go up even a little bit higher?
How is your tire PSI and alighment? That can make a little bit of difference also.
Wish me luck tomorrow.