The HYDI system generates its own hydrogen as you drive and directly injects it into the air-fuel mixture just before the combustion stage, altering the fuel mapping of the engine for optimum efficiency. The company claims a little hydrogen "helps the mixture ignite faster and more completely, resulting in greater power using less fuel and creating fewer emissions."

It works with a range of large diesel engines from six liters to 40 liters and beyond, and the company says it can reduce fuel consumption by between five and 13 percent, leading to return-on-investment times as quick as three months in non-stop scenarios, or up to 18 months with a city bus-type usage profile.