London's Formula 1 Buses

A flywheel from a Formula 1 car will be tested on London buses in hope that it can improve fuel efficiency as much as 30%.

The flywheel, developed by racing car builder Williams F1, captures energy from deceleration which is then re-used when the vehicle accelerates. 

Unlike massively heavy flywheel technology of the past, the Williams product weighs just 50 kg.   It stores energy not in mass like its predecessors but in speed, reaching up to 40,000 rpm.

Gas Misers - How They Stack Up

A lot of people are beginning to pay more attention to fuel efficiency as gasoline prices climb and the dangers of global warming loom. Here is the New York Time's "10-Best" list:

10 Most Fuel Efficient Cars

1. Toyota Prius 61/52 (city/highway)

2. Honda Civic Hybrid 49/51

3. Toyota Camry Hybrid 40/38

4. Toyota Yaris 34/40

5. Honda Fit 33/38

6. Toyota Corolla 32/41

7. Hyundai Accent 32/35

8. Honda Civic 30/40

9. Nissan Versa 30/36

10. Nissan Sentra 29/36