Can converted electric vans and donor vehicles really cut the cost of a new London black cab?

Relaxing London’s black cab turning-circle rule and other Conditions of Fitness could encourage manufacturers to convert electric and plug-in hybrid vans for the taxi market, but previous attempts suggest drivers should not assume that converted vehicles would be substantially cheaper than purpose-built taxis.

Mayor of London Sir Sadiq Khan had instructed Transport for London (TfL) to examine the long-standing manoeuvrability requirement as part of efforts to reduce the cost of entering and remaining in the taxi trade. TfL’s Seb Dance recently responded to such claims around the turning circle in particular saying the feature ‘remains relevant’ for the black cab industry.

The call for a review did however place renewed attention on vehicles such as electric vans and multi-purpose vehicles that could potentially be adapted for London taxi work. However, the turning circle represents only one part of a detailed set of Conditions of Fitness that every new taxi model must satisfy.

Under the latest conditions, issued in June 2025, a taxi must be able to turn on either lock and proceed in the opposite direction without reversing between two parallel planes no more than 8.535 metres apart. The document also specifies a wheel turning-circle diameter of 7.62 metres.

The requirement has historically forced van converters to undertake substantial engineering work. The Mercedes-Benz Vito taxi, introduced in 2008, needed an additional rear-wheel steering system to achieve the required manoeuvrability. The system turned the rear wheels in the opposite direction to the front wheels at low speed, allowing a vehicle based on a commercial van to perform the required U-turn.

Dynamo Motor Company later converted the Nissan e-NV200 Evalia into an electric London taxi. The company said the work involved more than 1,000 modifications, including changes to the roof, wheelchair facilities and turning circle. The finished Dynamo entered the market at £55,495 before the £7,500 plug-in taxi grant, reducing the price paid by an eligible driver to £47,995.

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That was significantly more than the price of the original Nissan vehicle. Evidence considered in an employment tribunal recorded a standard Nissan NV200 electric van at £22,999 in 2021, compared with £48,995 plus VAT for the converted Dynamo taxi. The evidence put the estimated turning-circle modification alone at £12,000, before accounting for the remaining taxi equipment and accessibility work.

The comparison illustrates why using a mass-produced van does not necessarily produce a low-cost licensed taxi. Manufacturers may benefit from an existing body, electric powertrain and supply chain, but specialist engineering, low production volumes, vehicle approval, accessibility equipment and taxi-specific components can quickly narrow the price difference.

TfL’s current Conditions of Fitness require new vehicles or conversions to satisfy the following principal dimensional and accessibility specifications.

Every taxi must accommodate a passenger travelling in a wheelchair. It must have independently anchored restraints for the wheelchair and its occupant, with the anchorages capable of passing the required static or dynamic testing. There’s also a host of requirements around door width and ramp lengths to contend with too.

The complete taxi must not exceed five metres in overall length. TfL says the limit is required because of taxi-rank dimensions, pick-up areas and the need to maintain traffic flow.

New models must also have a fixed-head body and a partially glazed partition separating the driver and passenger compartments. Further requirements cover lighting controls accessible to wheelchair passengers, a slip-resistant and contrasting floor, passenger visibility, an induction loop, an approved taximeter, an illuminated taxi sign and a TfL-approved card-payment device.

Emissions rules further restrict the potential donor vehicles. Since January 2018, every new taxi model has had to be zero-emission capable. It must emit no more than 50g of carbon dioxide per kilometre, provide at least 30 miles of zero-tailpipe-emission driving and use petrol rather than diesel if it has an internal-combustion engine.

A battery-electric van could satisfy the powertrain element, while a qualifying plug-in petrol hybrid van could potentially meet it if its emissions and electric range were within the prescribed limits. The larger challenge would be producing a complete conversion that meets the manoeuvrability, accessibility, dimensional and passenger-compartment standards while retaining sufficient payload, range and durability for intensive taxi use.

The Dynamo demonstrated that an electric van conversion can pass TfL’s approval process, and if the turning-circle was dropped and the savings passed onto buyers, it could be slightly cheaper than current market options.

The Dynamo project also demonstrated the commercial difficulties too. Although it offered an alternative to the LEVC TX, its final price remained in the same broad premium taxi market rather than approaching the price of its unconverted donor vehicle. There was also worries about the low range achievable on the model for a fully electric taxi, poor air conditioning functionality for passengers and small in size. Production later ended after Nissan discontinued the e-NV200 on which the taxi was based.

Scale presents a huge obstacle for any taxi entering the market. A mainstream van manufacturer can spread development costs across tens of thousands of vehicles, but a specialist London taxi converter must recover engineering, testing, tooling, warranty and approval costs from a much smaller number of sales. Changes made to the steering, roof, floor and wheelchair equipment can also create additional servicing and parts obligations throughout the taxi’s working life.

Removing or relaxing the turning-circle requirement could eliminate one of the most technically demanding modifications. It could also open the door to vehicles that already meet the five-metre limit and can be converted for wheelchair use without fundamental chassis changes. It would create an option at the very least.

It would not, however, remove the remaining cost of making those vehicles compliant. History suggests a converted electric or hybrid van may create competition and offer drivers a different operating proposition, but it does not guarantee a dramatically cheaper black cab.

The decisive test for TfL will therefore be whether manufacturers can present credible, fully costed vehicles rather than indicative prices based on unmodified vans. Until purchase prices, conversion costs, warranties, approval timetables and servicing arrangements are disclosed, claims of substantially cheaper London taxis from multiple interested manufacturers remain unproven.