Posted Monday, September 19/05 in Driving efficiently

Ever wonder how much of a difference specific car mods (or driving techniques) make to fuel efficiency?

So did the engineers at Honda.

For you economy numbers nerds (you know who you are), there's a particularly illuminating paragraph in an overview of the 2005 Accord Hybrid that attributes specific fuel saving values to each of the component technologies that make up Honda's hybrid approach.

These technologies are collectively responsible for an improvement of 8 mpg (EPA figures) in city driving (29 mpg compared to 21 for the non-hybrid V6 Accord) and 7 mpg on the highway (37 mpg vs. 30).

Care to guess which gadget/refinement...

(A) electric motor assist
(B) cylinder deactivation (3 cyl. mode)
(C) automatic engine shut off (idle-stop)
(D) improved aerodynamics

...goes with which increase in fuel economy?

(1) 38% of the total highway mpg improvement (i.e. 2.65 mpg of the 7 mpg increase)
(2) 05% of the highway mpg improvement (0.35 of 7 mpg)
(3) 57% of the highway mpg improvement (4.0 of 7 mpg)

(4) 60% of the city improvement (4.8 of 8 mpg)
(5) 15% of the city improvement (1.2 of 8 mpg)
(6) 25% of the city improvement (2.0 of 8 mpg)

Answers on the next page (plus "why are you telling me this -- I drive a Geo Metro!")