First, I am going to review this page about fuel saving technology:
Multistage Oil Pump: Talk about craptacular, oil pressure does little or nothing for an engine. Oil viscosity does a lot more for the engine. But, underflowing oil will destroy an engine. A multistage oil pump is only good for pumping failure. Better alternative – electrical oil pump.
Shortened Head: I sort of like the idea. But making the valve guides shorter means that the head is more prone to valve deflection. Toyota figured this out with the 3SGTE engines back in 1991: A bucket is used to shim the valves. Better alternative: Lighter metals = less mass, but this is a neat idea if they can pull it off.
Variable Compression Ratio: Good idea, terribly poor execution. This is traditionally accomplished with a dual-lobe cam similar to VANOS. Introduced in 1992, BMW’s system allows for 12 degrees of timing change. What could possibly go wrong with individual pistons? When the actuator dies, you’ve got a dead piston, and you need a new shortblock. I’m absolutely sure if the pistons get even a hair out of sync, the main bearing on your engine is toast.
Guided Spray Turbo: Anything that improves fuel economy through turbos is good. Buy stock. Best idea of the set. It’s tried and true.
Electromagnet Valves: Another really good idea. This engine is so tunable it’s stupid, and could probably run on CNG, LPG, E85, whatever. With a high pressure fuel pump and the right injectors, you could tune the dwell and timing to run on absolutely anything. Hell, you could even switch it from diesel to gasoline.
Hydraulic Power Electrification: Electric pumps are a good idea, but not a 100+ MPG idea. Still, every little bit helps. Or you could just be a man and learn to drive without power steering (LOOK AT YOU RED MR2).