[borski]

OK, so honest question: I have a 2012 Mazda 3 which, presumably, gets 40mpg. But I can't realistically get anything above 29mpg on average. Am I just an aggressive driver? :)

[edit] I agree, by the way, that the cars are incredibly fun to drive, for being "fuel efficient."

[pkulak]

If you don't spend 95% of your time on a freeway, you'll never get close to the top MPG. This is how people like to compare their cars to hybrids: their car's highway MPG to a hybrid car's combined. Problem is, the hybrid probably doubles the their MPG in the city. But, if you're a long-range commuter, I guess that doesn't matter much.

[syphilis2]

I have a 2012 Mazda3 sedan with the 2.0L Skyactiv-G engine. I drive a daily commute on a 50-50 highway/stop-n-go mix. My average mpg has consistently been 35 mpg (40 highway, 32 off). The hatchback has slightly worse mpg, so does the manual transmission, but 29 mpg sounds more like the non-skyactiv 2.0L engine. The 2.5L sport engine would be closer to 25 mpg.

I'd check under the hood just to make sure :) then fill up the tires, reset the average fuel economy, and baby it on the highway to see if you can get around the expected 40 mpg.

[bigtech]

Have you tried 'hypermiling'? https://en.wikipedia.org/wiki/Energy-efficient_driving

[greggyb]

2012 had half Skyactiv and half .. non-Skyactiv. The expected MPG on the non is around 30. You'd have a badge on the rear of the car (if sold in US, at least) that would indicate Skyactiv.

[borski]

I have the badge.

[greggyb]

I had the 2012 for a few years. When I was driving 80%+ highway, I would struggle to get below 35MPG or above 42MPG.

On a 50%-50% split, I would be in the mid 30s, usually 36MPG or 37MPG.

When I was 80% city, I would be around 32MPG on average.

That car does not have much low-end torque, so if you accelerate aggressively from stops you can definitely tank the MPG. I didn't see much impact from aggressive acceleration at highway speeds (e.g. going from 30MPH to 70MPH on an on-ramp, or pulling around a slow group of cars going from 45MPH-70+MPH). I did see a lot of impact from flooring it 0-30.

Hope this context is helpful.

[usrusr]

The correlation between efficient driving and aggressive driving is far from perfect. The "pulse and glide" method from the wikipedia page linked in a sibling comment would seem quite aggressive for example and on the other end of the scale, I have often seen "moving roadblocks" running their engine at RPM far too high for efficient cruising (e.g. when people drive a manual who are afraid of shifting).

[dsfyu404ed]

Hauling ass from one light to barely run a red on the next one is a hell of a lot more efficient than seeing the yellow, accelerating like an old man, coasting for awhile, braking to a stop and idling for several minutes.

Every time you touch your brakes you're throwing away the energy it took to get to that speed. Coasting through off ramps at highway speed is good for the environment.