Oscar_3748

I know that they increase hp, and sound; but what about mpg?

what do o/d pullies do for you

VARifleman

there's no such thing as o/d pulleys for one, if you're talking about Underdrive Pulleys then yes, those supposedly give you better milage.

Shawn02GT

yes exhaust will improve your mpg

reasoning: less back pressure makes it easier for the engine to expell the gas

red2k1gt

I say no...you have a tendency to hit the gas more so you can hear your loud exhaust

rbstang

[sm=exactly.gif]

monkeydude3

yes and no. yes if you continue to drive normal. no if you hit the gas more and love the sound of your exhaust.

this same thing came into effect on our 69 impala. we had true dual smooth bent exhaust put on. assuming i drove like a granny with it, i twould get better mpg. but it just sounds so da**ed awesome to let it rip!

spaided

I put a full custom exhaust with O/R X-pipe with the stock manifolds and my MPG has went up considerably. So headers would be great.

Chopper

When I installed the Bassani headers the before and after mpg's didn't change.The Bassani cat back did raise the mpg's by about one.

70 MACH I

I stayed the same in mpg with a power gain, with each exhaust improvement my car rolled better, I call it the "Jake brake effect", less back pressure, better roll off the gas. But mind you that is if you drive it easy, if you hammer it to listen to the "music" your mileage will go in the toilet. Most folks here who bitch about mileage, drive it hard, but don't get the connection. As I stated in a previous post, even gears won't hurt your mileage, if your' cruising RPM falls below 2400 RPM's, if you drive on the highway each day (with Gears) you can't avoid it. I drive my GT easy and get great (upper 20's mileage) my low is 25!

John