Puresilk - I reckon you're right. I've run mine to just below the empty line a few times and it takes 60 litres to fill it again, so the reserve must be 10 litres.
If I take it easy with my IS200 SE I get about 440 miles to the tank, so around 33 mpg. My journey is usually mixed between 20 miles motorway and a 3 mile traffic jam each day (M8 in Glasgow).
I've had a wee fuel economy calc on my site for a while. In addition to working out MPG it also stores a wee fuel ecomony "league table". Feel free to give it a go and add your figures if you like...
http://www.grantgibson.co.uk/misc/fuel-economy-calculator/
Cheers,
Grant.
