The US EPA hopes to put an end to the discrepancies in fuel mileage rates that current calculation methods are plagued with. The changes will be rolled out from the beginning of 2008 and are expected to reduce the estimates from 5% to 25%, but will still carry a warning that actual results may still vary. Since the way you drive is the biggest factor in determining how much your mileage will vary from official figures, results will always be viewed as estimates.

The Chicago Tribune gives real world examples, such as the case of Dave Warnke who averages 52 miles per gallon from his Toyota Prius, while his wife gets 42. The new rules would see the city rating for the Prius, which currently stands at 60 m.p.g, drop to around 45 for the 2008 model year. Most cars will see the city rate drop around 10% - 20% and highway estimates by 22% in an effort to bring them closer to real-world results.

Experts agree that an overhaul of the current system is long overdue, with many car and travel organizations already conducting their own tests. In fact, the EPA will incorporate the system used by the AAA motoring association and will add other factors in coming up with the new fuel economy estimates. Overall, the new rates will be closer aligned with the manner in which people really drive.