Is anyone here running one of these? I'm looking to increase my fuel economy more than anything and am curious if 16 would be possible with this. I have to do my plenum yet anyways so this would be another option.

 

You won't gain any mpg improvement, The hughes testimonials are pure BS marketing. The airgap is okay, not an exact fit but it works for our motors. Adds a small bump in power above 3000 rpm. And it eliminates the plenum.

 

Any one mod will not be a big change in any aspect... it is the use of complimentary mods together that get the best improvements.

I doubt 16mpg is a realistic goal for every day... at best you might get there with all the right parts and a deliberate mellow drive.
I know I feel good about getting 15, as most around here report 14 as good, 10-12 as common, and complaints start when 8-10.

The AirGap is designed for improvements at higher RPM, and is (by itself) a loss at lower RPM... but with other mods this can be offest.

If you goal is purely MPG and you want to maintain low end (where it is mostly driven), just do an aluminum plenum plate (Hughes, eBay, etc), and save your money.

As I said, I'm getting 15mpg with an AirGap, but as best as I can tell, the AirGap lost me 0.75.
The single best improvement I did for mpg was the HemiFever tune, gaining 2mpg.

 

Thanks guys. Ill go with the plenum fix then. My 97 got 14 consistently and in the summer was normally at 15 sometimes a little more. The 01 I just bought has a hard time getting to 12. I will fix the plenum and look into a tuner.

 

Yep. It pulls a little harder in the higher rpms and doesn't do anything for the mileage but not having a plenum gasket that can leak is nice.

 

I barely noticed a half mpg gain when I installed it but my plenum was shot pretty bad. The best mpg boost I got for the least amount of money was a new timing chain that got me .75 more mpg. I started at 10.1 mpg when I bought it. With the lift and larger tires I range from 13.5-14.2mpg.

 

I was looking at intake manifolds, it seems the 360 magnum dosent have all that much low end to begin with (mine has 3.5 gearing) would you lose enough low end to be noticed, I think my plenum gasket is in it's way out

 

I've got the hemifever tuner. Which setting (mine has three options) are you using that gets you the mpg increase?

 

If you do nothing else, yes, you'll notice some some bottom end loss.
This manifold starts coming to life at ~1,800rpm and over 2,000rpm is happily doing it's thing.

 

Well lovely lol, man I wish the intake wasnt so expensive. It's so easy to find 360 intakes just not ones with the holes drilled for the injectors