24 Jul 2009
I've done this too. My Passat 1.8T has a combined claimed average of 34 mpg. I exceed this all the time, even by driving normally, but I use the car for what it should be used for - long highway journeys rather than choking round town (which is why I always question the purpose of so called 'city' cars - chocking up town streets and so on). Anyway, on long motorway journeys, its not unusual for me to get 40-42 mpg by sticking to the speed limit. I tried going at 55 mpg and I got 46 mpg. It demands more concentration, but at the same time its a bit boring and tiring. A 4 mpg sacrifice to do 70 is worth it. A lot more could be done to transmission gearing to get higher mileages at motorway speeds.