Smaller Isuzu engine calls 3.0D future into question

ISUZU Ute Australia (IUA) has unveiled a new 2.2-litre diesel engine, based upon, and replacing, its short-lived 1.9-litre unit.

The decision has, however, called into question the future of Isuzu’s renowned 4J-series 3.0-litre engine, with the company suggesting the smaller engine may form part of a strategy that assists it in lessening its exposure to penalties from the New Vehicle Efficiency Standards (NVES).

The new RZ4F-series engine produces 120kW/400Nm, up from the outgoing 1.9-litre’s 110kW/350Nm, but down on the 3.0-litre’s 140kW/450Nm. It is backed by a new Aisin-sourced eight-speed automatic transmission – and will tow 3500kg (braked), in line with the 3.0-litre range.

The new engine also features an idle-stop system that is said to reduce fuel consumption and CO2 emissions considerably. The idle-stop system has also been added to the 3.0-litre range.

While the smaller engine buys time for Isuzu’s D-Max and MU-X models, it does not offer a viable long-term solution for the diesel-only importer.

IUA outlined a CO2 emissions figure of 174 grams per kilometre in the 2.2-litre powered D-Max and 177 grams per kilometres in the MU-X, both currently below the NVES threshold of 210 grams per kilometre for 2025 (see table below).

However, as the NVES threshold progresses to become increasingly more stringent, it is clear Isuzu Ute Australia will pay a penalty on every vehicle sold – costs which will likely be passed on to Isuzu customers.

While the entire IUA range falls within this year’s threshold, next year the emissions limit will be reduced to 187g/km, before dropping again to 150g/km in 2027, meaning even the 2.2-litre unit buys IUA two years at most.

The 3.0-litre engine, equipped with the new idle-stop system, emits 187g/km of CO2 in the D-Max, and 200g/km in the MU-X, so will not meet next year’s 180g/km limit.

Under the proposed fine structure, Isuzu customers could face penalties of $700 or more, while plug-in hybrid alternatives like the BYD Shark 6 PHEV (46g/100km) and Ford Ranger PHEV (66g/100km) remain unaffected by the tightening regulations.

Isuzu Ute Australia did not confirm whether its mild hybrid system available in other markets would be offered locally, or whether the system will be used on the 2.2-litre engine abroad.

It also ruled out the chances of equipping its 3.0-litre engine with the more efficient eight-speed automatic transmission.

When asked if the electric D-Max model revealed in Europe earlier this year is still on the cards for Australia, IUA provided a particularly vague response despite previously confirming the model.

“We are currently unable to comment on specifics relating to future model plans,” said an IUA spokesperson.

“That said, as part of our due diligence, IUA will continue to monitor the local needs and evaluate the reception of BEVs locally, and work with the factory to provide a product mix to meet Australian consumer needs.

“While Isuzu Motors Japan have advised that they started production on an electric pick-up (ute) for European markets in April 2025, we have no further information to share at this point in time.”

2025 Isuzu range fuel consumption and CO2 emissions*:

*Figures supplied courtesy of Isuzu Ute Australia.