the biggest problems with all cars these days, when run on a dyno with the air/fuel ratio, on average a car straight from the factory air/fuel ratio is about 11.0:1 to 12.0:1 on the dyno which is way to rich. Hench every new model notice there is a 5kw increase, thats because the manufactors lean the engines of slightly to give better fuel economy and that 5kw increase. when i brought my vy ss, i desided to do a fuel consumption test a no way on earth could i even match what they reckon they use, who knows where they done there testing, and under what conditions. So i took the car to work a decided to start to have a play, and ran the car on the dyno, and just what every car showed up, extremly rich. So i put a complete exhaust on the vehicle, changed the air intake tube to make the car breath better, and fitted a aftermarket ecu, and done a mild tune with 225rwkw. Noticable the car went much harder, and drove better. So i completed another fuel consumption test and my results were approx 500km to a tank round town and nearly 700-750km to a tank highway driving, which thats what i reckon a car should get to a tank. Even more i've now tuned the car up to 256rwkw, and im going to do a fuel consumption test over a month, to see if its any better.