Originally Posted by jtuds
What impact do these piggyback tunes have on fuel efficiency and the different drive modes?
I had GIAC in my 06 A4 2.0T. It's full software not piggyback.
My MPG increased by nearly 2MPG, driving it the same way day to day.
However, you get these tunes for one thing, POWER.
When you want and use more power, of course MPG will go down lower.
If your engine is developing 40hp and 50lb ft more than stock, then it will require more fuel to develop that power.
I prefer Full ECU software over piggyback as power levels increase.
This is one expensive piggy. It does appear to be an advanced piggy system as it plugs into various sensors, seemingly to take over the readings the stock sensors are putting out. It takes time and money to crack ECU protection codes, and perhaps this company didn't want to crack the ECU or couldn't. ECU tunes also use the OEM sensors, but they are taking the sensor readings by which to adjust maps, instead of using sensor readings and altering them to make the computer think all is well.
If this works in a different way, then I hope the manufacturer chimes in and explains.
Simple piggybacks are cool for modest gains around 4-5psi. The JB+ is one such piggy and it works great. I've driven a 135i with the JB+ and the added power is very noticeable, very. It increased boost by 4.5psi. over stock. The price is but a fraction of this thing.
With CAN tool and JB+ the cost is only $329!
Excellent price for the added performance, and the tool allows you read and clear codes before dealer servicing.
If there was one for the N55 that would be ideal for those who want more power, but want to keep it safe. It really does wake the engine up when you want it, and drives like stock when driven normally day to day driving.