2025 Isuzu D-Max and MU-X to gain new 2.2-litre turbo-diesel

The Isuzu D-Max and MU-X will become available with the Japanese brand’s new turbocharged 2.2-litre four-cylinder diesel engine from the fourth quarter of this year.

As in Thailand, where both vehicles are produced for Australia, CarExpert understands the larger and higher-output turbo-diesel will replace the unloved 1.9-litre oil-burner as the entry-level engine in Isuzu Ute Australia’s two diesel-powered models.

And we expect the new 2.2-litre engine, which is claimed to consume about 10 per cent less fuel than the 1.9-litre engine it replaces, will soon also power entry-level versions of the D-Max’s twin, the Mazda BT-50.

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Above: Thai-market D-Max 2.2.

While Isuzu’s big-bore 3.0-litre turbo-diesel will continue to be the flagship engine for the popular D-Max ute and MU-X large SUV (and the BT-50 ute) lineups, the new 2.2-litre engine will play a key role in reducing IUA’s and Mazda Australia’s exposure to emissions-related penalties under the New Vehicle Efficiency Standard (NVES).

Given its higher outputs and improved efficiency, it’s also likely to be more popular than the 1.9-litre engine, which made its local debut in the D-Max in 2022 before becoming available in the MU-X in 2024.

We understand the 1.9-litre engine has attracted fewer than 100 sales annually in the D-Max, which was Australia’s third most popular 4×4 ute in 2024 – behind only the Ford Ranger and Toyota HiLux – with more than 24,000 sales.

Above: Thai-market MU-X 2.2.

First revealed in November 2024, Isuzu’s new 2.2-litre diesel was listed by IUA as one of a range of powertrains options it could employ to lower its fleet-average CO2 emissions.

These include the battery-electric D-Max EV, which could top $100,000 based on UK pricing and is therefore expected to be a low-volume vehicle. At the other end of the scale, IUA is working on a hardcore Walkinshaw-developed Blade version of the MU-X, to join the D-Max Blade.

Isuzu’s new ‘2.2 Ddi Maxforce’ engine (codenamed RZ4F) is based on and replaces the 1.9-litre RZ4E engine, which produces just 110kW of power and 350Nm of torque.

Above: Thai-market D-Max 2.2.

The new engine develops 120kW at 3600rpm and 400Nm over 1600-2400rpm, and is mated to an eight-speed automatic transmission (rather than a six-speed unit as per the 1.9- and 3.0-litre diesels), which Isuzu says brings improved performance and fuel economy.

That’s only 20kW and 50Nm less than the 140kW/450Nm ‘4J’ 3.0-litre diesel that has long powered the D-Max and MU-X, and which will eventually be replaced by the new 2.2.

A mild-hybrid (MHEV) version of the 1.9-litre, revealed earlier last year, will remain on sale in Thailand in a single rear-wheel drive pickup variant. This produces an identical 110kW and 350Nm to the regular 1.9-litre.

It’s unclear at this stage if the 2.2-litre (pictured above) will eventually gain a mild-hybrid system.

While Isuzu hasn’t published fuel consumption figures, it says fuel economy has been improved by up to 10 per cent over the outgoing 1.9-litre. According to Australian figures, D-Max variants with the 1.9-litre use between 6.7 and 7.0L/100km.

The new 2.2-litre stacks up better against the entry-level four-cylinder turbo-diesels in the Ranger and HiLux.

The base HiLux Workmate’s 2.4-litre engine produces 110kW and 400Nm, while the Ranger’s single-turbo 2.0-litre engine makes 125kW and 405Nm, and both of them are matched with a six-speed (rather than eight-speed) auto.

MORE: Explore the Isuzu D-Max showroom

MORE: Explore the Isuzu MU-X showroom