I average 16-18mpg in my 420SEL in the city and 19-22 on the highway. Our cars are pretty much the same except your engine is a little smaller, and maybe lighter. I would expect you'd get a little bit better milleage than me, but it does depend on how you drive. I have a heavy foot personally. Hills use a lot of gas, for example the drive from Halifax to Toronto is 2 days. The first day through Nova Soctia, New Brunswick is a lot of hills, so the first 600 miles takes 35 gallons or so (17 mpg) the next day through most of Quebec and Ontario is mostly flat and the remaining 600 miles from Quebec City to Toronto takes only 25 gallons (24 mpg).