My brother was just talking to my dad about fuel-injections vs. carbs, we realize fuel-injection is more fuel efficient, but we aren't sure how much better it would be? Anyone know how much better the mileage tends to be?

 

It depends, but here is the very VERY short version.

Assuming an equal EFI vs Carb setup....

Carb is going to have just as good throttle response, and make slighty better top end power and possibly mid range power as well. It has atomization advantages over fuel injection. It's also substantially cheaper than EFI.

EFI will make better low rpm power, and possibly better mid range(it's going to depend on the setups), will burn cleaner so it'll produce less emissions and will get better mileage. It's also more expensive.

You can get EFI setups to produce the same top end power as a carburetor can, but they are not stock systems(except on exotics like Ferrari or Lamborghini), and are very expensive.

That's assuming equal quality systems that are both setup properly. The trick with carburetion though is that you have to know what you're doing with it to get the advantages to be realized.

As far as mileage improvements, that depends on what you're going from and what you're going to.

 

depends on the system too i know that ford didnt make fuel injected 65s or anything but fuel injections put into chevys those fuel injections were nothing like the fuel injections of today number one because they werent based on computers like they are today and number two these were some of the first fuel injectors of there day but now on new computer sabby fuel injections yes gas milage would be a little better but once technology touches anything it obviously will get better....

 

Ya my brother is going to get a new engine for his 71 Chevelle and he was talking to my dad about how much it would help/ not help if he got an EFI

 

With EFI you can have the best or both worlds (allthough will cost more). I have built one EFI and have been spoiled. Now I'm on the next build and it will be EFI also.

 

Any idea whether the MPG difference would be worth getting the more expensive EFI?

 

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I'm pretty sure my bro would want it to be his main car, so his DD

 

Efi does help the mpg but you need a over drive tranny and rear end geared to match the over drive ratio on the tranny for the most mpg.Also driving style has a lot to do with mpg so does up keep on the car.Most cars never got efi tell the 80s chevy had a mechanical fuel injection the rochester which was on some corvettes and belairs.Which was still basicly a carb.Hilborn another early mechanical fuel injection which was nothing more then webber side draft carbs.

 

Check out my website and read up on swapping to EFI.

The greatest thing, besides the 22mpg, is that I can go for a month without touching the car, then get in, hit the key, and it runs like I drove it yesterday. On cars that aren't daily drivers, you never keep carbs clean and in good tune.