Toyota LandCruiser 300 Series to return to inline-six diesel power?

Much has been written about the all-new Toyota LandCruiser 300 Series – including by carsales – and a lot of it has been based on media speculation, including the rumour that a new 3.3-litre V6 turbo-diesel will replace the 4.5-litre V8 from the 200 Series.

Now, well-placed sources have added weight to the idea that the downsized diesel in the 300 Series will in fact be the 3.3-litre straight-six turbo-diesel currently being developed by Mazda for the next-generation Mazda6 and CX-50, as the CX-5’s replacement is expected to be called.

News that Mazda’s new straight-six diesel will displace 3.3 litres was broken by the Cochespias blog back in April 2020, while reports of a new twin-turbo 3.3-litre V6 diesel from Toyota first emerged from Japan’s Magazine X in September 2020 and was subsequently widely reported.

We’re sure that Magazine X’s sources are impeccable, but given our latest intel it seems almost certain that Mazda’s new 3.3-litre I6 diesel is destined for the 300 Series – not a new 3.3-litre V6 diesel developed by Toyota.

For starters, Mazda and Toyota have a technical tie-up in which the pair will co-develop and produce an all-new SUV in the US from this year – powered by internal combustion engines and all-electric powertrains – potentially reviving the CX-7 nameplate for Mazda.

Separately, in return for Toyota’s hybrid and EV technology, Mazda (which will release its all-new MX-30 mild-hybrid here in April, followed by an EV version in July and a rotary range-extender option next year) will provide Toyota with its latest combustion powertrains.

Mazda has always said its ground-breaking HCCI compression-ignition petrol technology is available to any car-maker that wants to pay for it, and carsales understands its move to develop inline-six diesel and (3.0-litre) petrol engines for its CX-5 and Mazda6 replacements, which will also move to a new rear/all-wheel drive C/D platform, pre-dates any deals with Toyota as part of its push upmarket.

A leaked document suggests the SKYACTIV-D 3.3 engine will produce 210kW/600Nm in the CX-50, which will also be available with a 210kW/340Nm SKYACTIV-G 3.0 48V M Hybrid turbo-petrol six.

It remains to be seen whether the Mazda diesel six will be tweaked to match the 200kW/650Nm outputs of the outgoing Toyota LandCruiser 200 Series, which can tow up to 3500kg.

The same document indicates the Mazda CX-50 will also be available with 2.2-litre turbo-diesel and 2.5-litre four-cylinder petrol engines, the latter in both turbocharged and 48-volt mild-hybrid forms.

For Toyota, which continues to focus on petrol-electric hybrid tech and dumped diesel from all its cars and crossovers in Europe in 2018, borrowing Mazda’s advanced diesel tech eliminates significant development costs.

In the case of the 300 Series, it would also spell the return to straight-six diesel power for LandCruiser for the first time since the venerable 4.2-litre 1HZ and 1HD turbo I6 engines disappeared with the 100 Series in 2007, when the 200 Series arrived.

As we’ve reported, the 2021 Toyota LandCruiser, the launch of which was delayed from 2020 to later this year by COVID-19, will downsize from V8 to six-cylinder petrol and diesel engines.

The 300 Series is expected to be revealed in Japan in September with a Lexus-derived 3.5-litre V6 twin-turbo petrol engine paired to a 10-speed automatic transmission and offering up to 300kW/600Nm.

Aimed at other big LandCruiser markets like the Middle East, the downsized petrol powertrain will replace the 4.6-litre petrol V8 that was axed Down Under in 2019 and a hybrid version will follow.

We expect Australia’s version of the 2022 Toyota LandCruiser (pictured here in computer generated images) to arrive late this year, powered exclusively by the new Mazda SKYACTIV-D 3.3 inline diesel six and bringing big advances in design, technology, safety, refinement and efficiency.

In the meantime, sales of the 200 Series – the last V8-powered LandCruiser SUV – are likely to remain at record levels.