No vent that I know of. You pump, it foams up and stops. It goes down quickly at first but then goes slower and slower - foam, stop, wait, foam, stop, wait like, 50 times just to get the last couple gallons in.

All that fuel above the 'full' indication makes it look great like going almost 500 miles on a half a tank and I'm sure the range is extended but for every day driving and MPG calculations, I don't think it's worth it.

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250