[Danihan]

>Compression ignition and a supercharger fitted to improve fuel economy together deliver unprecedented engine response and increase torque 10-30 percent over the current SKYACTIV-G gasoline engine.*3

Wow. I already have a 2016 Mazda 3 that gets around 40MPG (even though it's not a hybrid) and it's already pretty peppy.

Probably the best car I've owned, and I've owned several nice sports sedans. Getting 40MPG is too convenient when you make longer commutes, not to mention the thing cost ~20k at 0% APR. Blows any hybrid out of the water for total COO.

[sundvor]

Agree, these are awesome cars. I have the 2014 Mazda 3 2.5l (SkyActiv) Astina, in a manual sedan. I do lots of commuting peak hour traffic, so my economy is seriously affected - I get about 9l / 100km on those days. On a proper open highway 100-110km/h drive I'll be on around 5-6l / 100km however.

Acceleration is very zippy indeed, and the manual whilst not inviting the most efficient driving is an easy changing, short throw type. Tech level in the car is amazing: Radar cruise, AEB, blind spot monitoring, rear cross alert, Adaptive Front Lights (inside lights looks into the corner), etc etc.

It's very exciting to see normal petrol engines becoming so much efficient. Kudos to Mazda here. I'm hoping they'll have a hybrid or even all electric out by the time it's time for me to upgrade the current one.

[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.

[mywittyname]

> Blows any hybrid out of the water for total COO.

Not so sure about this. I have a 2014 3i GT and my wife has a 2014 Prius. Hers was cheaper to buy, gets way better mileage (29 v. 44) and needs less frequent oil changes (which are free), and is worth about $1200 more now.

It's a little faster, nicer inside, and much more fun to drive. But cheaper, nah.

[raman325]

I'd assume the parent comment is referring to the base package version of the Mazda 3. I was able to get a 2015 Mazda3 S Touring for ~$25k with all taxes and fees included, so I think $20k is a fair estimate if you assume the base package

[neogodless]

Indeed. I was shopping recently and the 2017 Sport was going for under $18k with current Mazda incentives ($2k cash.)

(I ended up with a 2015 S GT for $20k - only 8k miles on the odometer :)!)

Also - that's an i (2.0L) which gets 30/40 mpg (about 34-35 overall) so not quite the stark difference in fuel economy compared to a Prius that the 2.5L has.

(gallons per 100 mile difference between 35 mpg and 44 mpg is 2.86 vs 2.27)

[IgorPartola]

I think you are misreading that. The increase of 10-30 percent is in torque, not MPG.

[ddeck]

This is correct, but they're are also predicting an equivalent improvement in fuel consumption:

"Compared to the current lineup of SkyActiv-G engines, the SkyActiv-X line should use between 20 and 30 percent less fuel."

http://newatlas.com/mazda-skyactiv-x-compression-ignition/50...

[flamedoge]

more torque = less rpm @ same hp?

[toxik]

Torque is directly proportional to power, related by angular velocity. So τ Nm of torque at angular velocity ω rad/s will give you power P = τ·ω in watts. In fact this works for three-dimensional τ and ω if · is the scalar product.

Oh and an RPM of N is equivalent to angular velocity ω = N·π/30.

[Danihan]

Gah, you're right, thanks. Edited.

[coherentpony]

Are those imperial gallons or US gallons?

[greggyb]

I can get 40MPG (US) highway with a 2015 Mazda3 and a somewhat aggressive driving style. City is usually low 30s.

The manual transmission is also one of the nicest I've ever driven.

These are great cars.

[aidenn0]

I only wish you could get the 2.5L in a manual with no moonroof. That would probably get me to buy a new car.

I have an 07 Mazdaspeed3 that is getting long-in-the-tooth, and it gets terrible mileage (19 in town, high 20s on the freeway). The best I can say about the shifter is that you get used to it.

I don't think I need quite as much pep as my current car (plus all current hatchbacks that are comparable performance are north of $30k), and the 2.5L engine in the Mazda3 is nice.

I like the Mazda3 better than the Focus, but if I had to get a car today it would probably be the Focus ST.

[thenewwazoo]

For what it's worth, I went from a WRX to a 2L 3i and don't miss the extra horsepower because we felt, frankly, that they're all slow, so why pay a premium for slightly less slow? With that said, it's plenty fast enough for city driving and is the most fun FWD drive car I've driven, bar none. Hell, it's the best car I've owned and only barely not the most fun (after my RX-7). The interior is great, it's cheap to run, ...

[aidenn0]

There are some dangerously short freeway on-ramps where I live, so "slightly-less-slow" can mean a few extra feet between me and a tractor-trailer.

[coherentpony]

Austin?

[prodikl]

loved my 6-speed 2015 mazda 6. highway miles were truly amazing for a full sized sedan. like others said i'm glad to see mazda continuously innovating. it's paying off

[Danihan]

US gallons

[serpix]

That is horrible mileage. I remember averaging that on a 1997 Opel Astra.

[MagnumOpus]

Your Astra weighed 1000lbs less, had no air conditioning and probably no air bags and would have probably killed you in a 40mph collision though, innit?

[dpark]

And that mileage was presumably measured using imperial gallons, which are 20% larger than US gallons. And it probably didn't get 40mpg anyway unless it was on the highway 100% of the time.

http://www.carfolio.com/specifications/models/car/?car=26732...

[mikeash]

Any chance your MPG was measured on imperial gallons? Looks like 40MPG imperial would be normal for that car, but 40MPG US would be a fair bit more than expected.

[aphextron]

As long as we're one-upping, I'll jump in here to say that my Nissan Leaf gets 140 MPG ;)

[tannhauser23]

You're trolling, right? 40mpg is pretty great.

[YSFEJ4SWJUVU6]

In certain contexts, certainly.

Modern small cars with small engines can be quite fuel efficient in highway driving, though, and there 40 mpg isn't quite the very top. A month ago or so I did a trip in a 2016 Seat Toledo (petrol, non-hybrid), and the drive computer reported the consumption as 3.9 L/100 km after 150 km of driving at speeds from 60 to 100 km/h, averaging IIRC 78 km/h.

A 80 km strip at 120 km/h increased the average to 4.2 L/100 km.