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Upcoming Mazda2 will offer new SKYACTIV 1.5-liter diesel

The upcoming new Mazda2 (known as Demio in Japan) will feature the SKYACTIV-D 1.5, a newly developed 1.5-liter clean diesel engine making use of the company’s next-generation SKYACTIV technology. Mazda unveiled the 1.5-liter diesel unit in the Mazda Hazumi concept at the Geneva Motor Show in March. (Earlier post.)

Similarly to the next generation SKYACTIV-D 2.2 clean diesel engine available in models such as the Mazda CX-5, the SKYACTIV-D 1.5 was developed in the pursuit of ideal combustion despite a very low compression ratio. (Earlier post.) The engine offers dynamic performance, including torque equal to a 2.5-liter gasoline engine and linear acceleration all the way up the rpm range. It also features excellent environmental performance without resorting to expensive NOx aftertreatment systems.

Along with utilizing numerous technologies from the SKYACTIV-D 2.2, additional advances were made to the SKYACTIV-D 1.5 to further enhance the engine and make it suitable for subcompact vehicles.

Additional technologies include an expanded homogenous lean burn range; further reduction in mechanical resistance; and insulation technology to curb the increase in cooling loss associated with a smaller engine size.

The all-new Mazda2 featuring the SKYACTIV-D 1.5 clean diesel engine will be introduced to the Japanese market where it will meet Japan’s Post New Long-term Emissions Regulations as a diesel-powered compact car.

The diesel will be combined with Mazda’s i-stop idling stop technology; i-ELOOP brake energy regeneration system; and high-efficiency SKYACTIV-DRIVE automatic transmission or SKYACTIV-MT manual transmission. Mazda suggests that the set of technologies will help the all-new Mazda achieve among the highest level test mode (JC08) fuel economy figures for a vehicle powered solely by combustion engine in registered vehicles excluding hybrid and micro-mini vehicles in Japan, as well as improved practical fuel economy.

The engine has a displacement of 1.497 liters; bore x stroke is 76.0mm x 82.5 mm. Maximum power output (net) is 77kW (104 hp) at 4,000 rpm; maximum torque (net) is 250 N·m (184 lb-ft) from 1,500-2,500 rpm.

Key new features of the SKYACTIV-D 1.5, many making their debut with this engine, include:

  • Development pursued ideal combustion efficiency despite the lowest compression ratio of any small displacement diesel engine—14.8:1 (among 2-liter engines or smaller). (SKYACTIV 2.2 diesels use a compression ratio of 14:1.) Reducing the compression ratio in a diesel decreases the compression temperature and pressure at TDC. Consequently, ignition takes longer even when fuel is injected near TDC, enabling a better mixture of air and fuel.

    To realize ideal combustion timing and duration as well as clean emissions at the same time, Mazda uses this premixed compression ignition combustion by controlling ignition timing based on model-based prediction of ignition delay in the low compression ratio engine.

  • Cooling loss is suppressed by combustion mode transition control technology and high dispersion solenoid injectors which, along with stepped egg-shaped pistons, help to reduce contact between the flame and chamber wall.

  • The range of homogeneous lean burn is extended through the adoption of high-pressure EGR and low pressure EGR systems, resulting in improved fuel economy, environmental performance and performance feel.

  • Engine cooling system features cooling water control valves (CCV) and water jacket spacers for improved combustion efficiency and reduced mechanical resistance.

  • Variable turbine geometry turbocharger with rotation sensor delivers plentiful boost pressure from low through to high engine speeds.

  • Water-cooled intercooler integrated into the intake manifold improves acceleration response and turbocharger efficiency.

  • Environmental performance to meet Japan’s Post New Long-term regulations and Euro6 emission standards without an expensive NOx aftertreatment system.





Again, this is an engine with comparatively low power density, same as for the 2.2 liter engine. Just scrolling through the list of features, I find little innovation compared to the 2.2 liter engine or compared to competitor engines. The new 1.5 liter engine has both high and low-pressure EGR, which the 2.2 liter engine did not have, but others were first (VW US spec. TDI, I think…) with these features. The 2.2 liter engine was the first to meet Euro 6 without NOx aftertreatment but today, others do the same, as e.g. the Renault 1.6 liter engine. In general, this article contains little data and more information would be needed to fully assess the progress in comparison to the competitors.

Engines of this size are about at the crossover point when a 3-cylinder engine would be preferred. Several such engines are now in the pipeline – or will be launched shortly. If these engines can provide the refinement and NVH claimed, there is not much rationale in choosing 4 cylinders for an engine of this size.


Hate to see people sucked into buying more dirty internal combustion engine cars because no one as yet can produced a good electric car for the masses. The Nissan Leaf and BMW i3 are badly range-limited and the Teslas are too expensive; all the others are CCCs(California Compliance Cars).

The main problem is still there; no one produces an acceptable battery for BEVs. The current batteries are too weak, too heavy and too expensive.

Face it, The greedy oil companies are hell bent on destroying the Planet and they are winning the battle.


There may well be little innovation between this and the 2.2 skyactive diesel.
The point is that it is better sized for smaller cars and should sell very well i Europe where small diesels are very popular in Fiesta and Golf sized cars.

@Lad, yes we await the battery or a good cheap range extender.
IMO, the range extender would do it.
if you double the range from 74 to 150 miles for the leaf, you will still have people who want to travel 400 miles in one day, while if you have a range extender, you can size your battery to your commute and go mostly ICE on long trips.


Face it, The greedy, inept electric car makers are hell bent on destroying the Planet and they are winning the battle.


Despite enormous efforts in government and private sector, there is not a battery with sufficient specific energy, life nor low enough cost to support a global shift in individual mobility solutions.

Therefore, Big Oil is trying to destroy the world.

The Logic is irrefutable.


I see little innovation in choosing a smaller engine for a smaller car. Do you?


@Peter XX, Do keep in mind that this is Mazda, a rather small car company. They are broadening their line up of high technology diesels. That is about it. As for 3 cylinder engines, is their a 3 cylinder diesel in automotive use? A 1.5 liter 3 cylinder is going to have some larger NVH than the 1.5 BMW gas. I assume that Mazda didn't just slice off a cylinder from their 2.2 because of NVH. That would have been quite a bit cheaper than what they did.

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