Flowmaster increase mileage?

[turnipgreen]

Did a search but didn't see anyone go one way or the other on this. I talked to a guy who says that by putting a flowmaster exhaust on his Dodge truck he gained between 1 and 2 MPG. Is anyone seeing a mileage increase with a change in just the muffler (or muffler and pipes)?

[KLS]

Likely a statement of the restriction inherent in stock Dodge mufflers.


Ken

[v8Toilet]

The best I got stock on the highway was 20.6 MPG. With the headers and a Spintech muffler I got 20.4 MPG going the same route at the same speeds using the cruise control. I didn’t see a return in gas mileage.

[Verndog]

Originally Posted by turnipgreen

Did a search but didn't see anyone go one way or the other on this. I talked to a guy who says that by putting a flowmaster exhaust on his Dodge truck he gained between 1 and 2 MPG. Is anyone seeing a mileage increase with a change in just the muffler (or muffler and pipes)?

Yes, I gained 1 mpg installing true dual, and flowmaster 70 series. I was running a TRD air filter at the time. Now funny thing about it, I went back to stock air cleaner, and lost my 1mpg. I ran that way about a month. After reinstalling TRD filter I got it back. So I believe there is also some truth to adding intake volumn when increasing exhaust volumn.

Also, I removed the stock Y pipe and added x crossover, which helped as well.

Kevin