Join Date: Jan 2016
Location: Harpers Ferry WV
Shut it off on my '13. '12 and '07 Avalanche 5.3s and it made no difference in mpg at all in normal mountain and small town driving. Did make a difference once a long flat 300 mi. trip on an Interstate at a constant 55-60 with no stopping about 80% cruise control in V4......whoopee! AFM saved a whopping 2 mpg when driving like grandma on an Interstate compared to normal driving on the return trip.
Used the Range Technology device which plugs into the diagnostic connector....works great and keeps a constant V8......returns to AFM as soon as it is unplugged with no footprint in the ECM to void warranty.
One reason I purchased a V6 Camaro is because it is cheaper and the other because it uses all its cylinders all off the time and not some GM gimmick to save a spoonful of gas.
Current Chevys - '15 Camaro LS '16 Silverado LT Z71; '16 new Malibu LT; '15 Traverse LT2
Previous Chevys: '13 Avalanche; '12 Avalanche LT; '11 Tahoe LT; '11 Malibu LS; '08 Trailblazer; '07 Avalanche; '06 Colorado WT....'80 Citation (POS); '75 Impala; 72 Chevelle; '69 Camaro R/T; '65 Impala SS; '62 Nova; '53 model 210