Which Gives Better Performance And Fuel Saving?

that is really a matter of circumstance and opinion as there are many benefits of both. carberators are simple to use and design, can be used for many different applications without anything but adjustments and are free of electrical problems most often. also the fuel tends to all evaporate for the most part in carb engines before the inlet valve(s) closes meaning often a colder charge can be had in every cycle making more power possible if all other things were equal. this is a big deal with some fuels.
fuel injection can be made very accurate and can deal with less volatile fuels than carbs can often. atomization is most always good. also the limitations of versatility is mostly a matter of programming with electric injection. mechanical injection systems have also been successful though like on VW rabbits. most people would argue that port fuel injection gives the best compromise of everything and i think its one of the best. it allows for a “tuned” manifold to be used with ease and EGR systems and the like are easily set up to go with it. with port injection the latent heat of the fuel cannot be used to cool the charge down as well though and power will be limited a little that way in theory. the cooling of the intake charge has an effect on thermal efficiency too, the colder the charge is from the start for its weight the better. both ways can last a long time no matter how you look at it but just have different vulnerabilities. as far as fuel use goes the big advantages seem to be with fuel injection but the latent heat of the fuel cannot be ignored for its effect on thermal efficiency and carbs can often get comparable mileage to FI cars. also carberated engines can often burn very lean mixes when no egr is used which is prevented on most modern cars by the computer. a modern fuel injected car with a 4 liter six might get 20-24 mpg on average but an old carberated ford 250 ci six(4.1 liter) can get that in a sedan with the right configuration. theres just no easy answer.