I have a fuel computer on my C5 and I enjoy checking consumption against varying speeds - sad isn't it? Mine is the 2ltr engine so expected figures will be lower than the 1.6. The highest figure I've ever attained was 60mpg at an average of 55mph over a 40 mile run. From that point, the higher the speed goes, the lower the consumption figure becomes. So at 70+ the consumption falls to 46mpg. Load, head wind or roof box will lower it even further. I also find it beneficial to switch off the cruise control on steep hill climbing. Whether or not the Piccy's computer is as accurate as the C5, I don't know, but I find the speedometer agrees to within 1mph with satnav. Also over a return run from London to Malaga, I kept a record of fuel fills and later checked the consumption against the amount of fuel purchased. Both records more or less agreed on the fuel consumption. Regarding oil dripping from the trunking. There's always a film of oil within the trunking to the turbo but probably there shouldn't be sufficient to drip. I haven't heard of it as a common problem, so it may just be a fault on that particular car.