Some of America's largest utes are set to arrive in Australia this year following an unconventional arrangement between the US and New Zealand.

Full-size Ram trucks capable of towing more than 13 tonnes will go on sale around October after Fiat Chrysler New Zealand secured the rights to import and convert American left-hand-drive models in unlimited numbers for sale in Australia and New Zealand.

The deal extends to Ram 2500 and 3500 models, vehicles currently available in the US with a choice of 5.7-litre or 6.4-litre petrol V8s along with a massive 6.7-litre Cummins diesel six-cylinder option providing 1170Nm of torque.

The top-end Ram 3500 diesel can carry more than 3.3 tonnes in the tray and tow payloads of more 13 tonnes. By comparison, popular four-wheel-drive utes such as the Ford Ranger have a towing capacity of just 3.5 tonnes.

Ram trucks are coming to Australia in 2015 Photo: Supplied

Ram is likely to target mining, caravan, equestrian and industrial operators with the ute.

Australian specifications for the models have not been finalised, though larger 3500 models are likely to cost more than $100,000 locally.

Similar-sized Ford F250 models imported and converted by Queensland's Performax International are priced from $105,000 plus on-road costs.

The deal was completed by the Fiat Chrysler New Zealand's Australian owners, Clyde Campbell and Neville Crichton, who will bring the vehicles in outside Fiat Chrysler's established Australian framework.

Ram trucks are coming to Australia in 2015 Photo: Supplied

The duo are also understood to be hoping to offer Ram's smaller 1500 - a model that could put them at odds with Fiat Chrysler Australia's Pat Dougherty, who told Drive in February that the model was in his sights as a local proposition.

An insider for company says it is too soon to say exactly how the models will be sold and distributed, only that they will be available across Australia.

Campbell says there is a clear demand for heavy utes in Australia and New Zealand.

"Until now the only way to own one in Australia was through a low volume aftermarket conversion. Our vehicles are being developed with the full blessing of FCA's Ram division," he says.

"They have worked closely with our engineers to produce a vehicle that is as close to an official factory right hand drive vehicle as it can be without it having actually run down the factory production line."

The Ram 3500 can tow more than 13 tonnes. Photo: Supplied