My 1990 300TE is about the same. I was told that the cold tranny holding the shift is due to emissions...makes the engine hit higher rpms early...which warms it up faster...warm engine equals less emissions. Hope its true as my wife complains about it all the time.

I have never gotten better than 20...and when it is all city..a bit of a heavy foot...I average around 17.

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1990 300TE....all comments are about this car...in case I forget in the actual post