I have Short ram intake and OBX header, OEM exhaust. However, i do have the Bullydog GT tuner.
There are 3 settings in the bullydog tuner. They are stock, regular, and premium.
Stock- run the stock settings.
Regular- run on regular fuel, gain around 10-15hp.
Premium- run on premium fuel, advance timing 2 degrees. gain around 20-30hp
These numbers were never been dynoed by myself, they are numbers from other nissan's owners.
Back to the topic. Such fuel economy setting does not exist. Fuel economy setting=stock settings+driving coach.
The driving coach will remind you the best way to save gas. It will show your instant MPG, average MPG, trip mpg(from when you start your car to turn off the car). It also show the wasted energy while accelerating or decelerating.
Other than the settings, the gauge itself is a great OBD II gauge. It shows your engine temperature, trans temperature, A/F ratio, rpm, speed, fuel flow, fuel economy, MAF flow, intake temp, also work as a OBD II scanner. Also able to adjust timing, speed and reviving limit by yourself.
I bought mine used on ebay for 138.00 shipped. Check out ebay, they got these around 100-200 range used. 1-200 you get all these gauges in front of you, and it has performance settings as well.
You do get better MPG if you follow the gauge's reminder. around 2-3mpg increase.
Engine & Tuning: Weapon R Intake|OBX TB Spacer|OBX 4-2-1 header|DC EX5012 aka fart can
Brakes & Suspension: Racingline FSTB|SE-R RSB|Brakemotive D/S Rotors+Ceramic Pads|Tein-S Springs|KYB struts
Interior: LED Interior,license plate, trunk and footwell| Carbon Fiber vinyl wrapped panels| DIY Voltmeter|35% tint|
Exterior:V-leds 6000k HIDs| Halo projector fogs with 6000K HIDs| Duplicolor Caliper Paint(Red)|light Smoked Taillights|
To Do: KYB struts| 35% tint|
Audio: Dual XDMAR6720| Kenwood P709|Kenwood P6994
Summer mode: 18" 350z V2 rims
Winter mode: 16" stock steels with General Altimax Arctic