[MasonPelk7]

I have a 2015 S.H.O. with around 80k and it gets terrible gas mileage about 13-15 mpg and when I fill it up only has a range of about 275 miles...I do mostly city driving but even on a highway trip I still only average about 15 mpg...I drive it like a grandma sometimes and it still gets bad mileage...?!??

 

[nateflik]

The moment you add fuel with more Alchohol and water the pump picks it up ( First ) , burns it quick at way less mpg . the once that level is used up your back to Normal Fuel burn rates, Seen this on many Cars . get a Damn alchol tester folks .
Kodi Lucky Patcher nox

 

[Simranto09]

. get a Damn alchol tester folks .

 

[95TaurusinSK]

I have a 2015 S.H.O. with around 80k and it gets terrible gas mileage about 13-15 mpg and when I fill it up only has a range of about 275 miles...I do mostly city driving but even on a highway trip I still only average about 15 mpg...I drive it like a grandma sometimes and it still gets bad mileage...?!??

Two things to try. First, check your air filter. If it's clogged, your gas mileage will go down. @Jeff K can give you some other suggestions (sorry, Jeff, to drag you into a six month old thread, but it's only gotten two responses, and neither are particularly helpful).

Second, My lawnmower previously took two full tanks of fuel to cut my lawn (2.5 liters). Before the last time I cut the lawn, I added seafoam to the tank of gasoline to try to correct another problem. The last two times I cut the lawn, it took just a bit over a full tank. Yes, it also corrected the problem that I was trying to correct. I can't guarantee that it'll improve your gas mileage, but it's worth a shot.

I'll add a third (and Jeff will probably agree with this). Check your brakes (service brakes and parking brake). If your brakes are dragging, that will also reduce gas mileage.

 

[Jeff K]

^^^ Agree about checking fr dragging brakes. My daughters 13 Limited has had rear brake issues for several years. I have to remove the slider pins and lube them up every year or the brakes drag. Just a few weeks ago, she came over and said something smelled hot at the rear of the car. From her house to our house is 95% freeway, so little to no brake use. IR thermometer showed pass side disk was 400 deg F, and driver side was 300 deg F and difficult to rotate the wheels by hand. Sure enough, slider pins were stuck again.

 

[chartmaker]

I have had stuck pins from rust, and one on the Buick that had no grease, clear never had grease. Also had a pad rusted in the yoke on Lin rear. On my Sable wagon, in my local driving I see ~130F or less. Maybe that is why I never wear out pads. I check my temps from time to time to see that they are the same side to side. Daughter's Buick had dragging brakes, like hot, under warranty, as the dealer OE pads they put on had burrs that stuck them in the yokes.
Dragging brakes use lots of gas. My opinion but it has to happen. I saw a case on a friends car where the pins were totally free but when the bolts were tightened, it was locked up. He bought a new yoke/caliper assembly and problem solved. He said his wife drove the car all the time and it had horrible gas mileage and the pads on one side lasted about a year. Pas side pads wear only, and on the outside only.
-chart-