ULEV technologies

Ultra-Low Emission Vehicle Definition

Before launching any campaign, all parties involved need to have a clear understanding of what a ULEV is. The Vehicle Certification Agency defines a ULEV as any vehicle that emits less than 75g/km CO2. To take into account advances in technology, the VCA expects that for a vehicle to be defined as a ULEV from 2021 the emissions will have to be less than 50g/km CO2. The definition is technology-neutral; it covers all fully electric vehicles and some, but not all, hybrids. ULEVs do not need to be electric.

In addition, many local authorities add on an additional requirement of having a zero-emission range of at least 10 miles. This may be put in place at a local level to maximise the benefit of any measures put in place, for example the bus and ULEV lane trial in place in Nottingham.


Toyota RAV4 Hybrid

A hybrid vehicle (sometimes referred to as a self-charging hybrid by some manufacturers) uses an electric motor alongside a standard internal combustion engine (either petrol or diesel). It will be able travel very short distances on electric power alone, at low speeds for example when parking or in traffic. Rather than plugging in to charge the battery, charging is carried out primarily by the energy produced under braking (regenerative breaking). There are no hybrids currently on the market that have emissions under 75g/km CO2, so there are no hybrid cars that are classed as ULEVs. Examples of hybrid cars include the Toyota Prius, Lexus CT200h and Honda CR-V Hybrid.

Increasingly, many manufacturers are introducing ‘mild-hybrid’ models which include a very small electric motor and battery to supplement the petrol engine, examples include the 2019 onward Mercedes C-Class petrol models and Suzuki’s SHVS-equipped models. Mild hybrids are not able to move under electric power alone. These are not classed as a ULEV. See hybrid car reviews here.

Key Point: Hybrids may be a stepping stone for many drivers, but a common perception is that they are driving an ultra-low-emission vehicle… they aren’t! They do have environmental benefits because of reduced emissions, however they are still an internal combustion energy car, and do not meet the ULEV definition.

Plug-In Hybrid (PHEV)

Mitsubishi Outlander PHEV with Michelin CrossClimate all-season tyres

Crucially, as the name suggests, a plug-in hybrid – which has a larger battery pack than a hybrid vehicle – requires charging from the mains electricity supply. PHEVs generally emit less than 75g/km CO2 so are classed as ULEVs. Many PHEVs could typically travel around 30 miles on electric power alone, however new models are now being introduced that can travel between 40 and 50 miles.

All PHEVs can be charged using a standard 3 pin plug (2.3kW) at home and with fast chargers (7-22kW) that are increasingly located in public car parks and shopping centres. Some of them can be charged at rapid chargers – these are generally located at motorway service stations, although more and more are appearing at charging hubs and petrol stations in or near major urban areas. Some examples of current PHEVs are the Mitsubishi Outlander PHEV, Kia Niro Plug-In Hybrid, Hyundai Ioniq Plug-In Hybrid and BMW 330e.

To make the most of these vehicles, they should be driven on electric power as much as possible, particularly when in built-up areas, using the engine for longer journeys. Maximising use of the EV element of the vehicle will ensure you can achieve the best fuel economy and will help to improve air quality in built-up areas. See plug-in hybrid car reviews here.

Key Point: It is important that any communications or engagement campaign promotes the maximum use by drivers of the electric motor in built-up areas to achieve the best fuel economy and help improve air quality. They are heavier than their petrol or diesel equivalent, and all that extra weight requires more energy to move it around, potentially resulting in more emissions. Electric power is key!


Battery Electric Vehicle (BEV)

Tesla Model 3

These vehicles are powered by an electric motor and have no internal combustion engine. They will have significantly larger battery packs than PHEVs. Many early BEVs have battery ranges from 90 to 120 miles. Increasingly, new BEV models have a range of between 140 and 250 miles, whilst some models from Volkswagen, Hyundai and Tesla can travel more than 300 miles on one charge.

As well as producing zero emissions from the tailpipe, these vehicles are exempt from congestion charge and clean air zone fees. For purchasers of new BEVs there is also a £3,500 plug-in vehicle grant available, car tax is free and from April 2020 there will be significant tax benefits for company car drivers that choose this type of vehicle. See electric car reviews here.

Key Point: Battery ranges have increased significantly with new models that have come to the market in the last 12 months; 140 miles or more is now the norm and we are starting to see more vehicles with even greater range. The average miles travelled per vehicle per day is much, much lower than that! These vehicles are exempt from all congestion and clean air charging zones, and many local authorities offer special, lower rate, parking permits too.


Range-Extended Electric Vehicle (REEV)

BMW i3s

A range-extended EV uses a small petrol engine as a generator to charge the battery and therefore increase vehicle range, or alternatively help to reduce concerns over range anxiety! These vehicles are charged in the same way as a BEV, using either a slow (2.3kW 3-pin plug), fast (7-22kW) or rapid (50kW+) charger.

These are now being phased out by many manufacturers as BEV driving ranges increase, although commercial vehicles are beginning to make use of this technology and the new London Taxi introduced by LEVC is a REEV.

Key Point: Manufacturers such as BMW and Vauxhall introduced range-extender technology to help reduce range anxiety when battery ranges were between 80 and 120 miles on one charge but they are now being phased out, in part due to EV ranges increasing. This technology is in use on the latest LEVC taxi cab and is likely to be applied to more commercial vehicles in the future.


Fuel Cell Electric Vehicle (FCEV)

Hyundai NEXO

This vehicle uses a hydrogen fuel cell to charge the batteries. There are currently very few fuel cell vehicles in the UK as the hydrogen fuelling network is extremely limited and the purchase price of these vehicles is very high. They currently offer similar efficiency and range to a petrol-powered car but have the benefit of emitting only water from the tailpipe.

Although the hydrogen fuelling network in the UK is very limited, Hyundai and Toyota are leading the way in developing hydrogen cars. They have similarly low emissions on the road compared to a BEV but, crucially, have much higher range and can be refuelled in 5 minutes compared to around 30-40 mins for an 80% charge using a rapid charger.

Key Point: The hydrogen fuelling network is currently very limited in the UK and FCEV vehicles and infrastructure are currently very expensive. This technology will appeal most to fleet users that have access to, or can install, the refuelling infrastructure and is likely to be the next source of ‘clean’ fuel for HGVs.

More information and reviews can be found on the Green Car Guide website and the Next Green Car website.


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