Great news that you've got it fixed and on your mpg record, best ive gotten is 440 miles on a tank
I just thought I would contribute a small bit since I'm studying Motorsport Engineering in college and my dissertion will be related to engines and fuel economy.
We tested a 1.6 direct injection modern mini engine on a rig and measured the fuel consumption from cold start all the way up to operating temperature on low load (low revs and dyno load) to get a slow warm up and the results were astonishing. Considering this an extremely modern engine with all sorts of gimmicky coolant and injector technologies the fuel consumption at low temperature was 4x higher than at operating temperature.
FOUR TIMES HIGHER!
When you consider that engines are only ~30% thermally efficient (we measured up to 25% in this engine) that £1 you spend on fuel translates to only 25p being used to move the wheels.
Consider our 1996 engines with relatively retro technology and the importance of careful driving whilst your engine is warming up is very important. Apart from the obvious hazard of wear whilst your engine is cold you will be using more than 4 times as much fuel!
In summary for good m/g km/l:
*Reduce vehicle mass (Acceleration=Force/Mass)
*On the motorway travel slower when time is not important (drag increases with the square of velocity)
*On cold start make sure that you drive economically (low revs; be patient; don't drive fast up hills!)
*Combine trips so that the engine is started as little as possible from cold (almost all of engine wear is created on cold start as well)
Once warm though..... rinse the VTEC!!!!