it was mixed driving, i do alot of highway driving.. so approx 100k's a day but there was quite alot of lifting involved... how can i resist?? :D my car usually does well with fuel... optimax has a opposite effect for me.. max ill probably get from it is 650mark... can someone explain what they mean when u say " running rich"... and is it good/bad for the car.. im only female dont understand too much about it he he