Technical terms

[Genie47]

MPFI has the injector just above the intake valve. Valve opens, fuel is injected.

 

DI or DFI has the injector shooting the fuel into the empty space above the piston.

[Tiger156]

so it does make sense to choose a car with more valves, cams and cylinders?

 

the only drawback is perhaps more of the above more prone to break down?

 

 

Engines with 6 or more cylinders will give a more balanced car because they are known to be dynamically/naturally balanced and do not require balancers. However, with all advancements, this slowly becomes economically untrue. More moving parts mean more friction, means more losses. Costs also increase, therefore you never see cheap 6/8/10 cylinder cars.

 

DOHC with VVTI is practically standard in the car industry now. The only thing is to see which company dares to push their engine towards their upper limits. E.g. Honda used to have a 1.6 with 170hp, and now have a 2.0 with 220hp (Euro R/Type R). As compared to the same engine with lower hp (non-Euro/Type R), these ones with higher hp may not last as long due to higher strain, heat, wear/tear of the parts.

 

Currently, the highest powered 1.6L will be 147 with 120 hp, 2.0L will be Euro/Type R. Of course we are talking about non-turbo engines.

[Yttrium]

I believe Genie and Tiger156 have given you very good answers already