I know this is an import site but I really want to try and find a muscle that has okay gas mileage that I can maybe tune. My friends bad mouth me because they are all rocking big muscle and they have the cash to pay for gas.  

theres no such thing as a muscle car that gets good gas milege.  muscle=high hp V8=less than 15mpg.  

you can go with a v6 muscle car. you wont get teh stock power of a v8 but they get 21 mpg in town. i have a friend with a supercharged v6 camaro that has about 350hp and he gets about 18 mpg in town when hes not gunnin it. they say if you turbo instead of supercharge youll only lose like 1 mpg.  

Even better you can go with a turbo 4cylinder and get between 18-23mpg city and 24-30mpg highway depending on which car you get, AND be able to run 11's with minimal bolt ons to it. My car gets 20/27 from the factory and runs low 13's, so I meet that requirement without dropping a dime in mods.  

^ 4 bangers FTW!  Theres a member on my honda forum with a 286whp Si and he still gets 25mpg highway.  considering all of the fuel upgrades he had to do to get that kind of power out of a boosted K20 i'd say its good mpg's.  

You can get the same power out of a 4 cylinder turbo and a V8, the I4 will get better mileage (and usually handling) and the V8 will get a loud rumble.

Fuel efficient V8's are non-existant.

Keep in mind you shouldnt give in to what your friends want for you, go for what you want.  

^word  

Most modern fuel injected V8s in cars get at least 20mpg if not better. My Cobra gets about 21 around town, Camaros with an LS1 can get high 20s on the highway and vettes get in the 30 mpg on the highway. It's all about how the car is geared most V8's don't come with numerically high gears for just that reason (and they don't need it as badly because they have the torque to make up for it). Also anything that has a t-56 6 speed (SS and Z28 camaros, corvettes, 03-04 Cobras, Vipers) has both fifth and 6th overdrive gears which really helps out with gas mileage.  

an 02 Camaro SS gets 19/28 so it doesnt quite meet the requirements. I know my 1991 MR2 Turbo got 20/27 according to the EPA and im sure that number can only improve with a few minimal mods, but I still advocate that a lot of your turbo 4cylinders get better gasmileage even with a 5speed with no overdrive, because it is lighter, and has less displacement.

The 03/04 Cobra's get an EPA of 16mpg in the city which also does not meet the mans requirements.

If your gonna build strictly a quartermile car, buy a v8. If you want a quartermile/autox/track/daily driver buy a turbo 4cylinder.

Even the most advanced 2008 Corvette gets like 16mpg/26 according to the EPA, not anywhere close to what I would consider daily driveable with gas at $4.00 a gallon.  

I have seen vettes getting over 30mpg on the highway, alot of it has to do with how you drive the car. Regardless once you start building a car with power in mind MPG least shouldn't be an issue. You can build a car to be cheap, fast, and reliable, pick two. Any type of power adder supercharger, turbo, etc. is going to kill gas mileage regardless if whether it is a 4 cylinder or not. An engine is just a glorified air pump so therefore the more air you pump in the more fuel you must add as well. If you have a 4 cylinder with a huge turbo on it , it will still get shitty gas mileage because with all that added air comes the need for more fuel. That is why V8s use more gas because they are pumping in more air because of their displacement and they need alot of fuel in turn to keep the air fuel ratio right. The two undecided factors are weight and gearing and last time I check EVOs, WRX's etc aren't exactly light.  

^ turbos only have an adverse affect on gas mileage when your boosting.  otherwise your gas mileage will be just the same.  

The turbo will pretty much always be making some boost except off idle maybe not maximum boost but it will not be the same as a NA 4 cylinder.  

I know the turbo spins but I dunno about it spooling up. It creates vacuum when off the throttle, and what if you have a really large turbo? If you have one that doesnt hit full spool til 4-5k rpms then you really spool barely if at all if your just daily driving it.  

The nice thing about the turbo is you can suck in as much air as a large displacement motor and make about the same amount of power, but with a much smaller motor. The turbo can compress air more efficiently than a combustion engine can and therefore is a boon to fuel mileage per hp compared to large displacement engines  

if he wants a muscle car he can always get a turbod datsun 280z. i know they push over 350hp. theyre really hard to find though. in crappy shape theyll still run you about 7gs. they run 1/4s in high 11s and low 12s, matters on how good you can drive. ive only seen 1, i didnt believe the guy until i saw the paperwork.  

^350 is hardly "muscle".  when i think muscle i think supercharged V8's putting out enough torque to make you throw up during a launch.