I've just got to tell someone (or maybe a couple of thousand someones...)
I've got an '89 300E with 116k miles on it. I've had it for about a year and a half, most of my driving was in town with some short highway driving. Gas mileage was around 20mpg combined. Not too bad for a 6 I thought.
About 6 weeks ago I took a job that causes me to drive 108 miles round trip every day, most of my driving now on the freeway at 70mph on cruise control. I was thinking that my gasoline bill was gonna kill me (always using Premium at avg. $2.05/gallon) but two things are improving.
The cost of gas is going down (now paying $1.83/gal for premium) and my mileage is up to between 25 & 26 mpg! On one tank I actually got 26.4mpg. YES!
Sorry, don't mean to brag or make anyone else feel bad, just had to share my "economy car" story.