i just got a brand new 2015 mazda cx-5 touring FWD and i get horrible highway mileage. the car currently has about 1500miles on it. i am a light easy driver, and i always calculate my mpg by dividing the odometer by how much i filled up at the gas station.

i went on a roadtrip this holiday season, and for the 2 tanks that i did highway only, i got 23 and 24mpg. i thought i was suppose to get 30mpg+?!?! i use cruise control and i usually cruise at 75mph/2.5krpm or 80mph/2.75krpm. when i check my odometer for the computerized current mpg, it does confirm that i only get 15-25mpg when i am cruising. for city/mix i have been getting around 28mpg, how do i get 23mpg by going highway only?!?! also, for those that say it could be caused by me driving too fast, i have never had this issue with any of my past cars

any ideas?

 

Using cruise control uses more gas. It keeps it at a constant speed by accelerating/decelerating all the time. Dead foot driving gets the best gas mileage. Other than that i could not say.

 

I disagree, I get outstanding fuel economy in my Mazda 3 by using cruise control. Even beating Mazda's economy spec.

 

you are not suppose to use cruise control for a new vehicle. You must vary speeds (and not floor it) for the first miles. This is the break in period. Don't expect good mileage til after the first oil change. I would also suggest getting the first oil change sooner as well.

 

guess i won't worry...for now. but today i filled up again, record lows at 21.8mpg, wow

honestly if i knew gas mileage would of been this bad i dont think i would of bought the car

 

I'd be pissed too, however i just noticed you drive fast. Too fast for good mileage. Your vehicle is not really aerodynamic like a Ferrari to get decent mileage at higher speeds.
Best mileage is @ 50 mph generally speaking. You should get close @ 60 mph.

 

Sorry to say that's as it gets for speeds above 60. I have 37598 miles on mine and thats what I get on trips. Driving around town, (under 55 mph) I get 37+. Worse with Cruise control. Watch your TACH. 2000 RPM's is the magic number. Anything over 2000, mpg will go down. These cars need a couple more gears, for high speeds. Don't know why they did'nt put an 8 speed in them.

 

I too have been only getting 23 or so mpg. Never above 24

 

Here's some real-world data on what you can expect: Mazda CX-5 Mileage | Fuelly

 

The operative word is "speed". EPA estimates are not taken at 75-80 mph. Aero drag and tire friction go up dramatically with speed. Expecting EPA numbers at these speeds is unrealistic. Try reducing speed to 65 mph as a test, and then see what happens to your mpg numbers.
Remember: Speed kills...mileage.