What Is the Difference Between a TX4 and a TX5 Black Cab?

The TX4 is a traditional diesel-powered taxi, while the TX5 is a range-extended electric vehicle. The TX4 uses engines from Ford or VM Motori to drive its wheels directly. In contrast, the LEVC TX5 uses an electric motor for propulsion, supported by a Volvo-built petrol generator that acts as a mobile power station. This shift means the TX5 operates with much lower emissions and avoids London’s heavy congestion charges.

Engineering and Powertrain Shifts

The TX4 represents the classic era of London motoring. We see these vehicles everywhere near Victoria Station or Heathrow. Most models produced between 2007 and 2017 by LTI rely on diesel combustion. They use a heavy gearbox to manage torque. The engine noise is distinct. It vibrates through the chassis when idling at a red light on Oxford Street.

These cars are loud. Drivers often deal with significant vibration during long shifts across South London. The diesel engines require frequent maintenance to meet tightening Euro emission standards. Reliability is high. However, the mechanical simplicity of the TX4 cannot match modern electric drivetrains.

The TX5 changed everything in 2017. It uses a range-extender system. A petrol engine provides electricity rather than turning the wheels. This setup allows for silent cruising in quiet residential areas like Richmond. The electric motor handles the heavy lifting of stop-start traffic.

It is efficient. While the TX4 burns diesel constantly, the TX5 manages energy through a battery pack. This technology reduces the cost per mile significantly for professional drivers. We find that the fuel savings often offset the higher initial purchase price.

The TX5 is quieter.

Visual Design and Economic Realities

You can spot the differences instantly. The TX4 has a rugged, somewhat boxy silhouette with visible rivets and separate headlight units. It looks like a tool. The TX5 features flush body sides and integrated headlight clusters that create a much smoother profile. It looks like a modern passenger car.

Design matters for passengers. The TX5 offers a more refined interior experience compared to the utilitarian cabin of an older LTI model. The doors close with a different weight. Light reflects off the TX5’s curved panels differently than the flat surfaces of the TX4.

Economics drive the transition. A used TX4 might cost a driver £10,000 to £15,000 on the second-hand market. This makes it an accessible entry point for new operators. The TX5 is a massive investment. New models cost approximately £60,000, which requires significant financing or high daily earnings to justify.

TfL rules dictate the lifespan. Most TX4s face a 15-year age limit under current regulations. This means the majority of these diesel icons will retire by 2026. Drivers must adapt or exit the trade.

The transition is happening.

Frequently asked questions

Does the TX5 run entirely on electricity?

No, it uses a range-extender. The petrol generator kicks in to charge the battery when levels get low. This prevents the driver from running out of power during long trips to places like Gatwick. It functions as an electric vehicle with a safety net.

Is the TX5 exempt from the Congestion Charge?

Yes, it currently qualifies for exemptions that the diesel TX4 does not. This saves a driver roughly £15 every single day they enter the central zone. These savings are vital for maintaining a profitable business in London.

Which taxi is better for wheelchair users?

Both models are fully wheelchair-accessible. The TX5 offers more modern interior space and easier ramp deployment due to its newer chassis design. However, the TX4 has a long history of reliable service for passengers with mobility needs.

Can I buy a new TX4 today?

You cannot. LTI stopped production of the diesel TX4 years ago to make way for LEVC models. You can only find them as used vehicles through specialist dealers or private sales. Most remaining units are quite old.

Why did LEVC switch to electric?

The shift responds to London's Ultra Low Emission Zone (ULEZ) requirements. Diesel engines struggle to meet these strict environmental standards without expensive modifications. Electric powertrains allow drivers to operate in any part of the city without extra penalties.

How much does it cost to fuel a TX5?

Fuel costs are lower per mile than the diesel TX4. Because the petrol engine acts only as a generator, it operates at its most efficient RPM. This reduces wasted energy compared to a traditional engine idling in heavy traffic.