[Stigmaru]

Originally Posted by serialk11r

FA20 appears to have cam phasing, no variable lift of any sort, as the head does not appear to have the space to accommodate the extra rocker/rollers/followers/whatever which all variable lift systems have. Sadly since boxer engines are so wide, I'm guessing variable lift won't make it for space reasons, unless they're willing to really change some stuff around. Valvematic doesn't provide a performance benefit in itself, but the better part load efficiency could give some emissions/efficiency headroom for larger cams for max power.

D4-S acts independently (as does any fuel injection) although timing is optimized according to the other parameters, if that's what you mean. I suppose D4-S + Valvematic (which needs to go with variable cam phasing to advance the cam when duration is shorter) makes tuning a bit difficult since lift dictates duration dictates load, and you would need to figure out direct injector timing not only at different speed but at different load as well.

Anyways, there's no reason a sports car should necessarily get worse mpg, just that up till recently engines have not been advanced enough to preserve fuel economy while offering high performance. D4-S seems pretty remarkable in that it can significantly improve combustion at low rpm even with a fixed profile cam that makes max torque at 6600 :O (besides the fuel economy/emissions benefits)

And I apologize that fuel economy appears in like 90% of my posts, I just like analyzing the thermodynamics a lot :P

In layman's terms: Not many $25K sports cars have direct fuel injection