Request ID: FOI-2410-2324 Date published: 27 October 2023
You asked
Therefore, (under an FOI request) and to ascertain the true reflection of the emissions difference between the LEVC running purely on fuel and an LPG conversion; can you please tell me from the approximate 7,800 LEVC taxis that TfL licence, how many of these taxis are running purely on electric? How many are running purely on fuel? And how many are running a mix of electric and fuel?
Additionally, (under the same FOI request) can you please provide the emissions data for an LEVC taxi running purely on fuel (i.e. g/km)?
We answered
TfL Ref: 2410-2324
Thank you for your request received by Transport for London (TfL) on 2 October 2023 asking for information about Taxis and the ULEZ scheme, following your correspondence with the Road User Charging Team.
Your request has been considered in accordance with the requirements of the Environmental Information Regulations and our information access policy. I can confirm that we hold the information you require. You asked:
Therefore, (under an FOI request) and to ascertain the true reflection of the emissions difference between the LEVC running purely on fuel and an LPG conversion; can you please tell me from the approximate 7,800 LEVC taxis that TfL licence, how many of these taxis are running purely on electric? How many are running purely on fuel? And how many are running a mix of electric and fuel?
In our most recent TPH Taxi and Private Hire Licensee Customer Satisfaction Survey conducted in November 2022, of 248 LEVC TXe drivers surveyed, over two thirds of LEVC TXe taxi owners stated that they drive their vehicle in pure electric mode more than 60 per cent of the time. The petrol range extender mode is used far less frequently, with more than half of respondents stating that they used it 40 per cent of the time or less. This is the most recent data we hold.
Additionally, (under the same FOI request) can you please provide the emissions data for an LEVC taxi running purely on fuel (i.e. g/km)?
We can advise that any new diesel TX4 taxi since 2016 has been built to conform to the Euro 6 emissions standard, although these can no longer be newly licensed in London.
However, there can be a substantial difference between the laboratory type approval test and real-world vehicle operations. For this reason, TfL refers to the COPERT emissions factors when estimating emissions from various types of road vehicle. The COPERT emissions factors are designed to represent how vehicles perform over a range of speeds and road types.
Using COPERT, a Euro 6 diesel TX4 taxi is estimated to emit 1.1g/km NOx in urban driving, Compared with 1.36g/km for a Euro 5 vehicle. Using standard fitment diesel particulate filters, Euro 6 levels of particulate matter emissions can be expected from any Euro 6 or Euro 5 diesel TX4.
Using the same COPERT estimates, but taking account of the LEVC ZEC taxi being a petrol plug-in hybrid, the NOx emissions are estimated to be 0.03g/km NOx under the same driving conditions, while a TX4 taxi, converted to LPG, typically emits 0.36g/km NOx. Therefore, an LPG converted TX4 taxi emits ten times more NOx than the LEVC ZEC vehicle, but two thirds less than a Euro 6 diesel TX4 taxi. Please note there are specific conditions for eligibility to convert to LPG on a London licensed taxi.
Unlike NOx, CO2 emissions are directly related to the fuel consumption of the vehicle. The Euro 6 diesel TX4 taxi is estimated to emit 220 g/km CO2 under urban driving conditions based on COPERT emissions factors, while the LPG converted TX4 is estimated to emit about 240 g/km. The plug-in hybrid LEVC ZEC taxi is estimated to emit around 55 g/km under similar driving conditions, provided that the battery is charged as necessary.
If this is not the information you are looking for, please do not hesitate to contact me.
Please see the attached information sheet for details of your right to appeal as well as information on copyright and what to do if you would like to re-use any of the information we have disclosed.
Yours sincerely
Jasmine Howard FOI Case Officer FOI Case Management Team General Counsel Transport for London
