2012 MKZ Hybrid mileage

[bwhay1947]

I'm a new member to the MKZ club forum. Bought this car in August of this year. Second owner. I'm retired, wife still works. She uses primarily for commuting to work. Great mileage until weather got cold. We live in E. PA. Is this from fuel changes they do every winter or could it be something else? Any comments?

[hermans]

Both of my cars do the same and I live in SE PA. Colder weather does affect the mileage on these cars.

[w2jo]

I have a 2014 mkz hybrid.  At about 40K miles, I had a transmission failure and it was replaced.  After the transmission was replaced, my fuel mileage dropped from about 41mpg average down to about 37 to 38.  The dealer said that this was "normal" and I continued.  I also noticed that the "road noise"/"wind noises" seemed louder than normal, but this too was deemed "normal".  About 15,000 miles later, I was on the interstate at about 75mph and noticed a "flapping noise" and at the same time, I noticed my fuel mileage dropped to about 32mpg for awhile.  But when I slowed down to about 60mph, the flapping stopped and the fuel mileage went back up to about 37mpg. 

 

I took the car back to my dealer and the mechanic inspected the car and found that a number of fasteners holding the plastic fairing under the car were missing.  The fasteners were replaced and ....  LO....and behold....  The noises stopped, the road and wind noises abated and returned to "new car normal".  In addition, my fuel mileage is back up to 41mpg.  average. 

 

So..  It seems as if your underbody fairing is hanging out in the wind, your fuel mileage can suffer and the wind and other noises rise in amplitude as well.  Maybe this report will help someone with the same problem.

Edited February 21, 2016 by w2jo