I've been tracking my mileage with the CL-S6 for almost a year now (since I got it). I average about 26mpg (good part of it is city driving and short distance as I work from home and take the back roads to the gym each morning). I use the government fuel economy website to track it which works nice. Cool part is that you can compare your mileage with others and share your info with them (only shows them what you get for mileage). Sadly right now there are only 5 other registered CL-S6 owners on there and none of them post regularly (some haven't for years). It'd be great if other CL-S owners tracked their mileage on there so we could all have a better comparison.

https://www.fueleconomy.gov/mpg/MPG.do?action=garage