I have been thinking about adding a slightly better cam than stock. My only concern is gas mileage, with my 305 Im currently getting around 20mpg, and this is crucial for me because I am a high school student and cant afford all the gas I want. So will adding a better cam decrease gas mileage?

 

That's a pretty loaded question but as a rule of thumb, the more lift and duration you run, the worse your mileage will be. If you throw some headers on there along with a decent intake manifold, the gains in mileage from those mods might offset the loss from a mild cam and I'd do those two mods first before touching a cam.

I bumped the cam in my '97 3.8L up to .512/.507 lift from the .460/.460ish stock cam (same duration), gained about 30 RWHp and lost about 1 MPG on the highway (from 32 to 31).

 

Drive your merkur when you want mileage, drive the camaro when you want fun!

But yea, do the other mods first (exhaust, air intake, etc) that increase efficiency, and have no negative mileage side effects. Then you can drop in a nice cam that'll give you more snap later. If you still small on the cam, (duration wise), you don't lose much for mileage. Going up in duration is where you'll feel it hit your wallet most.

 

My merkur is broke...turbo died

 

Then leave the Camaro alone.

Speaking strictly as the father of an 18-yr-old and a 16-yr-old, about the last thing you want is 2 disabled cars in your driveway, and to be riding the bus or {gasp of horror} bumming rides from your rents.

Come back and talk about cams when the other car works.

 

I'd hate to agree with an adult here, but I have to . He's right, there's nothing more irratating than your parents always having one up on you because you are borrowing their car all the time. Hell, I'm 20 and I still have to use my mom's car while my Camaro is down and I hate it.