I own a tl manual with a 6g75 and I average 600kms just around town driving and 800-900 on the highway.. Might sound hard to believe but I averaged 6.6 litres per 100km on the way back from sydney last month, it just clocked over 1000kms on a single tank than I chickened out and filled up.. Never had it running that efficient, normally around 7-8 litres per 100kms