I'm curious myself. I heard they supposedly improved the lubrication and cooling systems, as well as made it 1.6 vs 1.5L, probably to better keep up with Yamaha. I know the 1.5 is tried and proven, but the 1.6 has the supercharger that supposedly DOESN'T need rebuilding. I wonder about that... In all, the new design appears to be very similar to the original 4tec.