does the z tube help or hurt with gas mileage~? thanks!

"your g is fast and furious, my mazda is quick and angry"

 

it insignificantly helps...

 

Air filter nor intakes have any real measurable restriction until the throttle body is WOT and the rpms climb above say 4,000 rpm. Nissan designs everything to be minimal until torque peak rpm where it might be 1% from atmosphere all the way to cylinder..........at HP peak rpm it might double!
The throttle body plate is always the greatest restriction when even 75% open.

Cruise steady rpm mpg is just a function of displacement and O2 sensor accuracy and rpm.

Every 0.005 mpg counts as US government taxes the car manufacturers. Not much any normal human can accomplish to improve the design as they are tweeked to the nth degree.

Most aftermarkets do little if anything.........if the HP goes up [rarely much] the mpg has to go down as each HP requires ~~0.45 pounds of fuel per hour to create

 

thanks tech~

"your g is fast and furious, my mazda is quick and angry"