Any chips that improve FE for GMC truck gas engines
 

I've heard of performance chips that have an economy setting for diesel trucks but I wonder if there are any for gasoline powered vehicles. If anyone here is aware of a chip that will fool the ecm into lean burn for improved FE then please let me know. My truck is a 2009 GMC Sierra with a 4.8L engine. I'm looking to further the FE increases that I've seen due to aero mods. I think the engine is tuned for lowest emissions rather that max FE at the moment and if there is a way of tweaking the fuel map a little to lean out the mix a touch I think that that may lead to futher improvements in FE.

Thanks in advance (no pun intended)

Swede

I would like to know more about it too , since compagny like ''volo '' offer product and claim nice gain .