Which is better? It depends on how your car is engineered and how you are going to drive it, but I thought this screenshot I just bumped into in my notes might be a useful. It is a reminder about how the original VX was designed. I assume that they are using some approximation of the EPA test cycle for these estimates. Notice that gearing is credited with 21% of the FE gain of the 1992 VX over the 1991 DX at the time, while lean burn is credited with just 5-10%. In fact, all the vtec-e stuff amounts to less impact on FE than gearing.
