The Hazumi concept presented at the Geneva motor show overnight showcased a new 1.5-litre turbo diesel Skyactiv four-cylinder powerplant which was described as a "potent and high-revving" engine.
Mazda said it has a claimed CO2 emission level of less than 90g/km - meaning a fuel use figure of less than 3.5 litres per 100km is likely.
But despite the engine possibly being one of the most efficient diesels yet, Aussie buyers look set to miss out.
Mazda Australia public relations manager Steve Maciver told CarAdvice that the next-generation Mazda 2, which is likely to go on sale late in 2014 or early in 2015, is not expected to be offered locally with the diesel powertrain.
"We've never offered a diesel in that segment before, and because of the nature of that segment it's probably not likely," Maciver said.
Maciver said the most likely engine for the new Mazda 2 is the 1.5-litre Skyactiv petrol four-cylinder engine that is seen in the current Mazda 3 in Europe, rather than the ultra-efficient 1.3-litre Skyactiv four-cylinder currently found in the Japanese-market Mazda 2.
The 1.5-litre powerplant produces 75kW and 150Nm, and has claimed consumption of 5.1L/100km in the 3, while the 1.3-litre unit has 62kW/112Nm and uses just 3.3L/100km.
"If you look at what we've done in the past, if we've got a choice between lower- and higher-capacity engines, we've always taken the higher capacity from a drivability point of view," Maciver said, but reiterated that the company has not made any decisions as yet.
"It's got to be a good mix of efficiency and performance," he said.