Bridgestone Ecopia EP422 Plus 175/65R15 84H (allegedly "70000 mile") tires are alleged to be quieter and provide better gas mileage.
After 4 months, I can confirm they're much quieter than the cheap Dunlop's that came with my 2013 Honda Fit Base Automatic.
BUT...I don't see any significant difference in mileage.
I record my mileage with fueleconomy.gov and with fuelly.com and keep a spreadsheet.
I measure gas mileage by the numbers from the gas pump and odometer, not the car's computer (which tends to be close but usually about 0.5 mpg higher). With the original tires (air pressure kept at 35 psi for both tires) I got an average 30.68 mpg (about 50% city driving), 1/2013 to 2/2016, and with the Bridgestones: 30.25 mpg for the past four months. Less expressway driving than avg. with the Bridgestones may account for the difference: on long (200 mile+ trips) I typically avg. 35-37 mpg between fillups and haven't had any such trips on the new tires yet. I'm getting the same, typical, 28-33 mpg between fillups with the new tires I got with the old. In any case, there's not going to be any significant difference in mileage with the new tires as claimed by Bridgestone!


Details:
I had four Bridgestone Ecopia EP422 Plus 175/65R15 tires ($82.99 each) installed on 2/10/15 fpr a total of $427.76 at Costco, including everything (6% sales tax, balancing, old tire disposal, TPMS check, etc.).
It didn't include alignment which I had done for a single time for $91.26 elsewhere. I apologized to the saleswoman where I got the alignment done for not buying new tires from her and she replied, "Oh, that's ok. The EP422's are great tires - you'd have paid well over $100/tire for the equivalent here.

 

If you're getting 30 mpg in a Fit, tires aren't going to help much. Yes, every little bit helps, but mpg isn't just something you can throw parts at.

 

After 7 months of recording mileage after getting the Bridgestone Ecopia 422 Plus tires, the mileage is within 0.2 mpg of the original, cheap tires and that can be accounted for by variations in city/highway driving.

 

I mentioned it only because Bridgestone claims it improves mileage. I didn't see it. It did make driving the Fit significantly quieter.

 

Are your Ecopia tires at 35 PSI too?
Ive keep my stock Dunlops at 42 PSI front and 40 PSI back and Ive been at 36-37 MPG overall.
Will buy Blizzak WS80 for winter and Ecopias 422 plus for allseasons, as my Dunlops are done (60,000 km / 37,000 miles).