MPG w. Headers and Tune

[Cjymiller]

Hi Friends,

I'm curious to know, is MPG adversely affected when running a header and exhaust? My initial thought would that it would increase MPG as a result of optimized "breathing" room, but I have no experience with this.

Thoughts? Experiences?



Cheers,

-Chris

[CBR600RR]

more power = heavier foot = more gas consumption

[mad_sb]

you should see some boost in mpg under cruise conditions. Better VE = better torque = less throttle required for same cruise speed as stock.

[NickFRS]

While my car was stock I was getting an average of 30-32MPG. ATM my car is tuned w/full exhaust + main resonator deleted in my intake @ 191WHP 150TQ. <- just numbers. I average 30-31MPG now. Nothing really changed. Still go 300-330 miles on a tank. Only difference is I can get to speed faster and I don't need to downshift as much or get into the higher RPM band now that I have max torque at 3k RPMS and 7k RPMS.

I have a custom BRZ edit tune though so it's different then the guys with ECUtek internet tunes.

[NickFRS]

Originally Posted by mad_sb

you should see some boost in mpg under cruise conditions. Better VE = better torque = less throttle required for same cruise speed as stock.

This ^

Only thing that changes while moding a car is the WOT mileage. At that point it's fun per mile!!! ahaha. But cruising speeds with more HP usually will stay close to stock. Depends how you drive.

[reeves]

I've had my CAI + header & over/front pipe + tune on my car for ~$5K miles now.. What's most noticeable is how much easier it is to get better MPG on the highway now.. due in large part to the extra torque above 3K rpms like others have said. Before my header/tune combo, I had to actively TRY to drive conservatively to get 30 MPGs or higher.. i.e., cruise under 75mph (under ~3200 rpms), try not to accelerate too hard going uphill or when passing around slower moving cars (not stomping on the gas unecessarily), etc... Yea, it was a terrible compromise to get "good" MPGs.

Now, I can drive NORMALLY and even exhuberantly at times, cruising at HIGHER speeds (75+ mph) and higher RPMs (3500 rpms & above) and STILL easily get the same or better (usually better) MPGs.

Going on several out of state trips:
When my car was stock, I averaged 28-31 MPG on those trips.. traveling 75-85mph.
Now, I get 30-33 MPG traveling at those same speeds, depending on how much hard accelerating I do.
If I drive like an old lady (tried it twice on 2 trips), I can EASILY get 34-36 mpg cruising at 60-70mph.. Once, I ran really low on fuel and HAD to painfully cruise slowly along at 50-55mph. I swear I think I almost got close to 40mph haha.

I'm fortunate to not have to do too much stop-n-go driving, but the times I have been in them, I haven't noticed any difference from stock.. mainly because I still mix in alot of hwy driving before/after those stop-n-go situations, so its hard to really estimate that.