I bought a 2017 Cruze hatch 1.4 gas 6sp manual about 2 months/3500 miles ago and the highway mpg has gone down from about 40 to the low 30s. I also noticed a bit of hesitation sometimes when accelerating. Are there any common problems with the turbo or powertrain that I should be aware of? Should i just take it into the dealer? Any input is appreciated.