Wayne Gerdes is an expert driver. Not because of his speed or race-track credentials, but for his Feather Foot. Or, to use the auto vernacular, he's an expert hypermiler: one who can achieve super mpg's from just about any car. This week Gerdes achieved an amazing 78 mpg, setting a new Guinness World Record for achieving the lowest fuel consumption in the lower 48 states in a non-hybrid car. After 8,122 miles and 16 days, Gerdes and co-driver Bob Winger's impressive economy numbers were witnessed by Guinness World Record representatives, sealing and official record. The team set off earlier this month, with the aim of beating a previous 68 mpg record for diesel vehicles. Gerdes himself also holds the equivalent hybrid record, set last year with 64.5 mpg in a Kia Optima Hybrid. "We felt we had a good chance of beating the existing record with a series production Passat TDI," Gerdes said after taking the record. "...But to smash it by averaging over 78 mpg is reall…