I am considering the purchase of a Mustang GT 5.0L with the following enhancements; "ported heads and intake mainfold with oversize intake and exhaust valves, 65mm Throttlebody, cobra mass air sensor with 24lb injectors and ecu, K&N high flow air filter, SVO high ratio roller rocker arms, adjustable fuel pressure gauge, underdrive accessory pullys, full length headers and mac 3" exhaust with flowmaster mufflers, 3:55 read end gear".

My question is what affect will these changes have to the original gas mileage ratings?

 

it will go down a few mpg's im sure. if you are looking for gas mileage then you should probably steer clear of modded mustangs.

 

I am just wondering what affect the mods might have. Someone out there must have done something similar?

 

Has the timing been altered? The 24 lb injectors sure aren't gonna HELP fuel economy!

 

Ryan answered your question as best as anyone could. Of course the mods are going to hurt fuel economy, but even a person with the exact same mods is not going to give you an exact amount, there are too many things that could effect it. Put it this way, the mods are going to make it lose between 1 and 10 mpg.

 

Thank you all for your input. I guess I should keep searching for the right mustang.