Fuel economy increase with a new HCI?

[dstang01]

Dont get me wrong, I know stangs arent for fuel economy, but this would be a very nice incentive to a new HCI Has anyone experienced actual increased fuel economy with an aftermarket street HCI setup? In theory, the more efficient parts should yield better economy when you stay off the loud pedal, but has anyone actually documented this?

 

[Dino Dino Bambino]

Doing an HCI conversion should improve the brake specific fuel consumption of the engine and make it more efficient. The question is whether you'd be able to resist the temptation to use the extra performance in order to see any mpg improvement. It's more likely that you'd rev the engine higher to enjoy the improved top end breathing and the soundtrack, so your mpg would also be more likely to go down the toilet as a result.
Would anyone really do the HCI conversion and then drive like a granny to save on fuel costs?

 

[StinkinLincoln]

i take it easy every now and then so the fuel gauge wont move. its really suprising, i bet i can get 20mpg if i stayed out of it. i would prob get 12 if i drove it like i wanted all the time

 

[illwood]

I gained probably 2 mpg with just an intake manifold and throttle body.

If you have a look at the stock intake, cylinders 1 and 5 IIRC have a pretty restricted (and curvy) intake path.

That 2 mpg gain is only true when I stay off the skinny pedal.