I used to get around 400 - 450 K's when i didnt worry about what sort of fuel I used. Now My best was 580 (Still trying for 600). If I drive the car really hard for the whole week I still get around 480! I only use BP Ultimate, It is by far the best I have found and I only go to servos which I know are really busy! They get more fuel more often... So Find one of those huge BP Sites and See how ya go! It worked for me. Definatly worth paying extra for it considering the gain in distance.