Not really. Identical cars, one with EFI and one with a properly tuned carb will get nearly identical mileages. Now, EFI will yield better mileage once the engine becomes well warn, since EFI is able to adjust a/f mixture accordingly..
Aww- I gotta throw my two cents in...
EFI can also compensate for changes in air density/altitude and temperature, as well as other factors. Let's also not forget that EFI tends to be part of a complete electronic engine mamagement system that also controls the ignition system, altering spark timing and such to suit conditions. The best EFI system will beat the best carb for overall efficiency because of this. Carbs are "dumb", meaning that all you can do is have an ideal "overall" set up, but there is not a means of compensating for varying conditions on the fly. Another added bonus for the offroad nuts amongst us, is that a fuelie will operate at any angle.
On the other hand, the simplicity of a carbed engine makes life good for home mechanics. There's not much to go wrong- so it's pretty simple to diagnose without a Cray supercomputer, Man, I could tell you stories about pulling out hairs troubleshooting fuelie problems... Carb systems are basic. Air, Fuel, Spark, Compression. Time it right, and your engine runs. On the other hand, there's so many dang components and sensors on a modern fuelie system, you can literally go insane trying to get an engine to run right...
im thinking about getting something like this because my muffler broke off and the ends are rusted to nothing
but im not sure how loud it actually is and if id get a ticket for noise
http://www.jegs.com/i/Cherry-Bomb/545/87502/10002/-1?parentProductId=769804
Those 'bombs can get pretty obnoxious. Picking up a ticket for excessive noise is not hard to imagine with those.