Simple calculation: 5 L reserve (on my AT the switching time is really exact the 18 liters consumed, the manual tries to suggest :-)) lowest comsumption 4,5 l/100km -> 110 km on reserve (strolling through Southern England and Wales) usual comsumption 5,7 l/100km -> 85 km on reserve highest comsumption 6,8 l/100km -> 70 km on reserve ( :-))) ) HTH, Frank