Robert Wiseman Dairies’ distinctive black and white lorries could soon be powered by gas or fuels made from used cooking oil and tallow.

The dairy company has confirmed that it is to invest up to £500,000 trialling two alternative fuel options in a bid to reduce carbon emissions.

Wiseman is likely to convert up to 20 vehicles to use liquid nitrogen gas and 35 to run on bio-diesel. The dual-fuel vehicles require conversion to add the LNG tank and run on diesel until the engine is warm. They automatically switch to run on gas which reduces engine noise and increases miles per gallon by more than 30%.

Wiseman’s fleet of 1500 vehicles covers 50m miles a year moving milk to and from its network of dairies and distribution centres throughout the UK. The company has already invested £318m in a state of the art dairy network, staying close to major milk fields and arterial roads into towns and cities.

Results from an earlier small scale trial using LNG on two Wiseman vehicles showed positive results, suggesting that articulated vehicles running on a combination of LNG and diesel could reduce annual carbon emissions by around 11,500kgs per vehicle.

Chief executive Robert Wiseman said the company wanted to expand its trials of alternative fuel systems to determine how they might bring benefits in the longer term, both to the environment and to the cost of running the fleet.

“Initial work suggests that the LNG system might be suitable for transporting milk from our dairies to our distribution depots using articulated lorries, whereas bio-diesel might have a better use in our tanker fleet making collections on farm and transporting milk to our dairies.

“We will monitor the progress of both these alternative fuel projects and aim to roll out suitable systems across our entire fleet in due course if they prove beneficial.”