Yes. Everything was thoroughly tested before and after. Two additional reference vehicles with identical drivetrains have been owned for multiple years. With the 10% ethanol gas we have, in a 5.6 liter M117, low to mid-teens is it.

The 4.2 liter M116 and 5.0 liter M117 engines get measurably better mileage than the 5.6 does. Trust me, I own and have owned up to three 5.6-liter 2.47 vehicles simultaneously -- two of them with low mileage. I know what they get.

If you baby the throttle, put it on cruise control, and drive 60-70 MPH....you can probably get 19 MPG, and perhaps crack 20 MPG with a rabbit's foot on your rear view mirror and with a tailwind. But nearly 100,000 miles of driving a 560SEC, and keeping track of every tank of gas, most of it with a 3.06, tells me that 13-14 MPG is generally what the car delivers on today's gasoline, in mixed and city driving.