I ask because I thought I'd find some figures for an equivalent diesel car. Trying the VW Passat, I found these :
6-speed manual:
Pferdestärken 163
Fuel Consumption
Urban 28.5mpg - 9.9l/100km
Extra-urban 53.3mpg - 5.3l/100km
Combined 40.9mpg - 6.9l/100km
Engine emissions 186g/km
Engine maximum Speed 134mph - 220km/h
Engine acceleration 0-62mph 9.6secs
5-sp. auto:
Pferdestärken 163
Fuel Consumption
Urban 24.4mpg - 11.6l/100km
Extra-urban 48.7mpg - 5.8l/100km
Combined 35.8mpg - 7.9l/100km
Engine emissions 213g/km
Engine maximum Speed 133mph - 214km/h
Engine acceleration 0-62mph 10.7sec
http://www.volkswagen.co.uk/new_cars/passat_saloon/engines#(those are British gallons, which are 1.2 US gallons). That engine is about 160 HP.
So, this new hybrid does get better urban economy, but worse cruising.
But look at the difference in the transmissions! You can save more than 10% just by stopping being a lazy bastard and changing gear yourself.
In the UK, if you pass your driving test on an automatic transmission, you're only licenced to drive an automatic transmission (because most people are pretty poor at using a manual the first time they try it, so they're not so safe on the road)- so nearly everyone learns to use a manual gearbox.
What are the US requirements - does it vary by state? If the rules were changed to be like the UK, could US teenagers be weaned off the teat of automatic transmissions, and introduced to the world of responsible adult motoring?