theunchosen: I'm no Honda expert, but I didn't think that the CRX ever had a lean burn engine. (SVOboy's VX-equipped MPG monster notwithstanding.)
I found this list (wikipedia) of Hondas that have used lean burn:
Source:
http://en.wikipedia.org/wiki/Lean_bu...n_burn_systems
The HF got its good fuel economy the old fashioned way: light weight, relatively good aero, small conventional engine & tall gearing.