Press Release

July 2022

HP Taxis, Prins Alternative Fuel Systems and SBL-Automotive are delighted to reveal their evolution of the LEVC TX taxi and VN5 van. The evolution has seen the development of a bi-fuel system for the range extender engine allowing it to adopt alternative and renewable fuels in place of petrol. These fuels are Compressed Natural Gas (CNG), Liquefied Petroleum Gas (LPG), Biomethane and Biopropane.

Adopting these fuels allows carbon emissions from the range extender engine to be reduced by 10% when LPG is used, 20% when CNG is used and by 99% for these fuels renewable counterparts of biomethane (in place of CNG) and biopropane (in place of LPG). Biomethane and biopropane can both be made from waste feedstocks such as food waste, farm waste and sewage and both are in volume production already. Biomethane and biopropane are ‘drop in’ replacement fuels for CNG and LPG and require no changes to refuelling infrastructure or to a vehicle already evolved with a bi-fuel fuel system (CNG or LPG). All of these fuels are available today and also offer 30-50% operating cost savings. Further savings are expected as biomethane and biopropane production volumes continue to ramp up.

The evolution of the TX and VN5 was first revealed during London Climate Action Week and on 27th June 2022 at our launch event at ME London, 336-337 The Strand, WC2R 1HA with the vehicles available for viewing between 11am and 5pm.

On 28th and 29th of June a TX fitted with the LPG/biopropane bi-fuel system was displayed at Reset Connect ( at ExCeL London and available for viewing between 9am and 5pm.

Details of the bi-fuel evolution of the LEVC TX and VN5 can be found on our website


The bi-fuel system consists of the following components:

  • Prins VSI-3 DI system
  • LPG/biopropane fuel tank or CNG/biomethane fuel tank
  • LPG/biopropane vaporiser or CNG/biomethane pressure regulator (both warmed by engine coolant)
  • Gaseous fuel injectors
  • Bi-fuel ECU

The Prins VSI-3 DI system comes with a 3 year warranty.

The LPG/biopropane evolution of the TX adopts a 50 litre fuel tank and the CNG/biomethane evolution adopts two 40 litre fuel tanks. Considering the vehicle range using petrol, the LPG/biopropane tank provides a further 90% of this range and the CNG/biomethane tank provides a further 70% of this range. Based on LEVC’s WLTP drive cycle based range figures of 64 miles using the battery and a further 319 miles using the 36 litre petrol tank (so total range 383 miles) the bi-fuel evolutions therefore deliver a further 287 miles for LPG/biopropane and 223 miles for CNG/biomethane. Total range is therefore 670 miles for the bi-fuel LPG/biopropane evolution and 606 miles for the bi-fuel CNG/biomethane evolution. A number of fuel tank solutions are also being developed for the VN5 including placing the tanks under the floor rather than in the payload area.

We are also working with fuel manufacturers and suppliers to grow the existing refuelling station network for CNG, biomethane, LPG and biopropane. If you are interested in adding LPG/biopropane or CNG/biomethane refuelling facilities to your site to support these vehicles then please do get in contact with us via our website.

Conversion costs are still in development but we target the system paying for itself in 12 to 18 months. This of course depends on the number of miles driven, the miles per gallon achieved and future changes in the price of the fuels. Prices for biomethane and biopropane are expected to decrease in the future as production volumes continue to ramp up.

On the road the zero carbon


About HP Taxis

HP Taxi is a taxi fleet and taxi rental company based in London and the first LEVC TX only fleet in the capital. Our fleet is the largest in London to be solely using the LEVC TX. We believe we lead the way in establishing the cleanest, greenest fleet in the country. TX black cabs are reliable and versatile and recognised as the world’s finest and most iconic of taxis. By working with the most knowledgeable and sustainable drivers we have a team to be proud of.

“We are very excited to again be leading the way in green renewable technology for taxi fleets in London and believe this new technology can help us transition in a green and viable way. It also fits well with the higher strategic goals to make London the leading city for green urban mobility.”

Paul Byron, Director HP Taxis


About Prins Alternative Fuel Systems

Prins was founded in 1986 as a Dutch designer and manufacturer of high-quality alternative fuel systems for LPG, CNG and LNG. Prins is a part of Westport Fuel Systems.

We have been a pioneer of fuel system development for more than 35 years. Regardless of the application – cars, buses, trucks, industrial or marine – we offer a solution for almost all engine types and technologies. The fact that we offer solutions for the latest and most modern direct injection (DI) engines also distinguishes us from our competitors!

We ensure that our systems are in line with the latest developments in the industry through collaboration with our dedicated partners worldwide.

  • Award-winning innovations
  • Extensive product range for DI engines
  • Dedicated and highly qualified staff
  • Focus on quality and sustainability
  • One-stop shop
  • Worldwide service network

“We are very pleased to work with this great team and contribute in lowering emissions. Especially with this Prins VSI-3 DI system, drivers will experience no difference from driving in the normal petrol-hybrid mode.”

John Wouters, Sales Director Prins Alternative Fuel Systems


About SBL-Automotive

SBL-Automotive is an engine research and development consultancy and has been active in the field of alternative and renewable fuels since 2008. We have also completed product quality, product and vehicle development work, engine calibration and aftertreatment testing for numerous vehicle manufacturers / OEMs. We have led the work to collaboratively develop the bi-fuel evolutions of the LEVC TX and VN5.

“The LEVC TX and VN5 bi-fuel evolutions show how the range extender engine can adopt lower carbon alternative fuels and net zero carbon renewable fuels. Internal combustion engines don’t need to use fossil fuels and here we show how they can evolve to lower and net zero carbon emissions. Thus offering a net zero carbon range extender function for these vehicles. Delivering lower to net zero CO2 emissions and lower running costs for operators too”

Shimon Shapiro, Director SBL-Automotive.