Fuel economy improvement with Berk HFCs and FI CBEs
 

I've seen the question asked a few times, "Will my fuel economy improve/worsen with mods x, y, and z?"

For the Berk HFCs and F.I. CBE, at least, I have an answer of sorts. The best combined fuel economy I ever saw when I was completely stock was around 18.5 mpg. This was not driving conservatively or aggressively all the time, but more a combination of the two depending on circumstances.

Now that I've had the HFCs and exhaust installed for a while (and reset the ECU after installing them), I decided to reset the mpg calculator on my Z and see what my numbers would be without the pre-mod information tarnishing the results. Surprisingly, my average after a few hundred miles has been 21.5mpg - a full 3 mpg improvement! Furthermore, I definitely go WOT more often and generally drive harder because I like hearing myself now that I've got this beastly sounding setup. :)

Anyway, just figured this information might be useful for those who were curious.

yea...ive gotten 2-3mpg better after installing all the breather mods as well, but as you know, once you hear it you stop being easy on the gas :tiphat:

I saw a nice decline with my FI CBE because I kept jamming the throttle to hear that beautiful noise. :tup:

I still see improvement despite accelerating more aggressively... as you two said, 'cause I like the sound. :) The fuel economy gains are just not as significant, but they're still there.