I first wrote about UK firm Tevva Motors back in January. Since then, the firm’s three test trucks have been in daily use and have now clocked up almost 30,000 miles between them.

One of Tevva Motors’ 7.5t test trucks, featuring the firm’s range extender electric powertrain.

Tevva’s powertrain is fitted to two converted JAC N-series trucks (JAC is a large Chinese manufacturer) and has also been retrofitted to a Mercedes-Benz Vario. All three vehicles are in daily use with parcel giant UPS, which is using and managing the trucks in the same way as the rest of its fleet.

Each vehicle has Tevva’s next-generation electric range extender powertrain, which Tevva says is capable of reducing greenhouse gas emissions by up to 80%, compared to an average 7.5 tonne diesel engine truck.

Range extenders work but combining an electric powertrain with a petrol or diesel-powered generator, which can be run to provide electrical power to keep the battery topped up on longer journeys. One of the key advantages is that the engine required is much smaller than it would be if it was used to power the vehicle directly. Tevva’s 7.5 tonne trucks have a 1.6-litre diesel engine fitted in place of the standard model’s 3.8-litre diesel engine.

Tevva’s powertrain uses the firm’s patented Predictive Range Extender Management System (PREMS) to work out the optimum time to run the batteries during a pre-planned route. For example, PREMS would ensure the batteries were charged to allow electric operation in urban areas before running the engine to top up the batteries during out-of-town driving. This offers significant benefits in terms of emissions and fuel consumption.

According to a recent review, the PREMS system has three modes, which provide varying levels of charge, depending on the state of the batteries and expected power requirements.

Tevva’s does not expect to start producing its own new trucks for another couple of years. However, the firm’s powertrain is now available as a retrofit package for customers who would like to fit it to existing trucks.

Range extender systems have always seemed to me a good medium-term solution to address range limitations of all-electric vehicles. As I’ve mentioned many times before, delivery vans and trucks are ideal candidates for electrification because they tend to do limited mileages on set routes each day, before returning to base each night where they can be charged.

Back to base trucks doing urban deliveries are Tevva’s target market. The potential benefits seem clear, so it will be interesting to see whether any of the big fleet operators — most notably trial partner UPS — can be persuaded to take up this system.