I recently purchased a 2025 Mazda cx5 select with the 2.5L naturally aspirated engine, and I noticed poor miles per gallon on the highway. I get about 24 mpg in the city, but closer to 22 on the highway, which is shockingly low. I’m not sure if it’s because I’m going too fast (80-85mph) or what but please let me know if you guys experience this too or have any tips!

 

Too fast & to soon. Give it a couple of thousand miles to break in.

 

Still, that is exceedingly strange. 22 on the highway and 24 in town? Going 80+ will certainly use more gas but it should still be over 25mpg. Most folks who post MPG on the forums for NA 2.5's say 30MPG or even better on the highway. It should improve with miles though. Our 21 turbo averaged 24 MPG over the 37K miles I had the car.

 

Im getting 30-31 on winter gas with a 2025 preferred. You may want of slow down,before you hurt someone.

 

I'm at 800 miles with my 2025 (with Cylinder Deactivation). Just did break in oil change putting Mazda 0-20w oil "with moly" in bought from the dealer.


Round town suburban 35-40 mph roads I saw 24 for the first few hundred miles, now 26.

Highway too early to benchmark because havent taken long enough trips but I do notice the CD feature operates a lot more at 55-60mph than 75-80 speeds. This is clearly a the exponential increase in wind resistance requiring more power than just 2 cyl mode can muster. So this car probably has a bigger step down in economy for real fast freeway driving than those without CD.

 

Considering you're still breaking in the new engine and drivetrain, I wouldn't stress out too much. Try to gether the data over the next few weeks and see if your mileage improves.

 

We have noted that the Skyactiv engines and TRANSMISSION take between up to 700 miles to fully break in to achieve the best overall power levels and MPG. .
Regardless of the service schedule you should get a engine oil and filter service at 3000 miles. During that period is when the highest amount of unwanted material is in your engine most collected with the oil filter.

I shouldn't mention the transmission when I feel based on direct observation and hands on serving them experience and dozens of oil analysis performed. unless you ask to many diss agreements with members that are not in the service business,

 

i have a '25 preferred NA awd with 25k miles on the clock and getting around 27-30mpg on the highway going around 75-80mph

 

The comparing MPG with anyone and on forums requires that the condition must be the exact or very close to the same operating environment and at least similar driving habits or numbers can be less reliable to use as a comparison. This is always a debate and often discussion on forums. But it's simple you should after the engine and transmission are completely broken in should get the stated high and city + average overall MPG on the retail sticker on the window of on Mazda's direct only website.
I might add that driving above speeds above 60 mph require more engine energy that is produced from more fuel and backed by imperial facts, about aerodynamic and aerodynamic efficiency and ground effects

Vehicles are not yet deigned like a rocket or airoplne ..YET!

 

Ditto. Gotta let it all break in.