I'm not very technical, but I would think a heavier car, and bigger engine (2.5L? vs 2.4L?) would use more fuel.

Now i know a lot of the numbers are all calculations made by the manufacturer and theses are not real world numbers, but i'm really curious how the 2G is more efficient, especially when thats one of their major selling points.

could it simply be dismissed as better engineering? has anyone driven both generations and have any noticeable differences or is the difference between the two very minor?

 

It's probably because of the additional transmission gear; the 6th gear, should allow for a lower cruising RPM which in-effect, should be more efficient comparatively.

 

Roller rocker arms
Dual VVT-i
Variable-induction intake manifold system
oil-jet cooling of pistons
6th gear
electric power steering
other low friction components