Guys,
I've been keeping track of my mileage in my 240D.
It's an 83, 4 speed manual, mix of around town and highway driving. I never cruise more than 62mph on the highway. On the interstate, I like to cruise 58-62mph. Odometer doesn't work, so all my mileage is based on GPS odometer. It has air and cruise control, but neither work.
I've tracked nearly 3600 miles and over that distance, it has gotten right at 35mpg. No additives, just Home Depot diesel. I did change the oil and install Delo 5W-40 synthetic in it this last weekend so I'll see if that improves mileage any.
I bought the car on Feb 10th and adjusted the valves a week later. About a week after that, one if the 14 year old tires suddenly deflated at 60mph, so I put a new set of tires on it, too. I've kept track of the mileage since I got it.
I've owner well over 100 cars so far and this one is in my top 5 all-time favorites. It accelerates slowly, but once it gets wound up, it'll cruise at 80+ all day long. Just don't make me lift!
When I bought the car, it had been sitting under a carport for 8 years. I should have changed the oil when I got it, but just didn't have the time and it ran so well. Over the first 3500 miles, it only burned a quart of oil. Based on that and it's relative oil-tightness, I felt it was definitely worth synthetic.
Plus, it's my favorite color: medium blue over dark blue M-B tex. I've got several friends bugging me to sell it to them.
Ben Pender
Fat-fingered from my iPhone