Loss of Mileage after Intake install
 

Hello All,
I installed AAM cold Air Intakes a week ago on my 2016 Nismo Z and my Mileage dropped from 22.9 mpg to 20.3 mpg. I have not been driving hard and there is no change in my right foot behavior.

Is the drop in mileage normal? I expected no change/better mpg with a CAI.

If it helps, I installed AAM midpipe and resonated shortails a month ago. These are the only breather mods I have on the car.

Thanks,
Nik

Generally speaking, a cold air intake should add hp. More power is an increase in engine efficiency. All other variables being equal, an increase in engine efficiency will increase mpgs.

https://media.giphy.com/media/EouEzI5bBR8uk/giphy.gif

From reading through the forum about Fuel Economy and breather mods, I came to an understanding that the increased volume of air would be compensated by more fuel by the ECU, to maintain the AFR. This seems perfectly logical and explains my lower MPG. Although, some people do seem to get better MPG with breather mods.

Potato skills in Installation. I was just concerned if I messed up the install.

lol. Totally missed that :inoutroflpuke:

i have breathers and drive hard. i believe my mpg is avg of 18.9 last i checked.

I suspect the difference in mileage is partly based on the year of the car. Later year Z cars are better able to adjust fuel to match increased airflow. In an earlier vehicle, chances are good a CAI would lean things out, somewhat improving mpg. My mpg definitely dropped after adding power mods. I still get decent fuel economy at 65 mph (27-30 mpg), but everywhere else in the power band it's much lower (but 20% more power, which consoles me).

With both intake and exhaust mods, a tune is probably called for. The ECM can adapt to only so much.

Yup, Deciding between ART pipes and HFCs. Will get a tune immediately after. I live in Michigan and would have to drive a few hundred miles to get a tune. (Thinking Dynosty). But hey, there's always Seb too.

Well I average around 14 - 15 mpg, so it doesn't matter what mods I do. LOL

And yes, my Z sees redline almost daily. I have to make sure that little orange LED in the tach still works every day you know.

Did you install the AAM with the inserts installed (S-line mode)?

Did you reset your ECU so it could relearn your setup?

Also, after a month or two with my AAM, every clamp needed to be retightned, seems like a little heat made the flexible couplers shrink.

Yes, I installed it with the inserts and reset the ECU.

Thanks, I will make sure I inspect the clamps after a few weeks to see if they need to be re-tightened.