Fit doesn't have a diesel yet... the iDSi stands for Dual Spark. The 1.3 iDSi has a secondary sparkplug to improve combustion efficiency at ultra-low loads and rpms.
The record for fuel efficiency in
local eco-runs was set in one at over
141 (US) mpg, but this is a freak occurence, and has not been repeated. The
usual poeak efficiency in highway runs with conservative driving is around 75 (US) mpg.
It's an amazing engine, but with a 0-60 at 14 seconds for both the CVT and manual version, and a top speed of "merely" 105 mph, Honda doesn't think it'll sell in the US.
The Hyundai 1.5 turbodiesel has 110hp and 177 (frigging) foot pounds of torque. It's been tested at 49+ (US) mpg in highway runs locally. If Hyundai ever federalizes it, I think the US market would like it. It gets from 0-60 in around 9 seconds, and returns a real world consumption of 33-40 mpg in urban conditions... at par with Honda's 1.3 iDSi, which typically returns 33-40 urban mpg driven normally with the CVT.
But then, Honda's 1.3 does 54 (US) mpg in urban conditions (read: heavy traffic) if driven "eggshell-under-the-gas-pedal" style.
The efficiency of these engines is one of the reasons why I'm not quite sold on current Hybrid technology.
