TfL Ref: 2096-1718

Thank you for your email received by us on 1 November 2017 asking for information about CO2 emissions of double decker buses in London.

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 for:

Could you please let me know the average carbon dioxide emissions in grams per kilometer (or equivalent calculations eg. kg/m) of New Routemaster double decker buses? I've been able to access information on other pollutants, however there is very little information available on their carbon emissions.
Please see the following table for the average CO2 and NOx emissions figures for buses operating as part of TfL's contracted London bus fleet, per year, for the past 10 years:
Fuel Body type Emission standard Approx Euro Std intro date NOx (g/km) CO2 (g/km) 
      
Diesel Single-deck Euro II 1996 11.429 1032.0 
  Euro III 2001 12.335 1128.8 
  Euro IV 2006 8.653 974.8 
  Euro V/EEV 2009 8.142 942.2 
  Euro VI 2014 0.670 936.4 
 Double-deck Euro II 1996 11.914 1290.2 
  Euro III 2001 15.455 1429.5 
  Euro IV 2006 10.418 1370.0 
  Euro V/EEV 2009 10.555 1326.1 
  Euro VI 2014 0.624 1349.3 
Hybrid Single-deck Euro IV 2006 15.852 726.6 
  Euro V 2009 4.533 784.5 
  Euro VI 2014 0.504 784.0 
 Double-deck Euro IV 2006 8.792 856.1 
  Euro V 2009 8.900 866.7 
  Euro VI 2014 0.201 938.1 
New Routemaster Double-deck Euro V 2009 2.048 690.2 
 Double-deck Euro VI 2014 0.456 675.1 

I would also like to know whether this answer is generally the same across all buses in the fleet, or if those with faulty hybrid engines which essentially only run on diesel have a different level of CO2 emissions

Whilst it was identified a few years ago that there were hybrid batteries on a batch of New Routemasters that could cause some engines to default to diesel mode, they were replaced as quickly as possible and continue to operate as intended.

We are committed to keeping CO2 levels as low as possible. At the same time the principal focus of the Mayor’s Transport Strategy is to reduce oxides of nitrogen (NOx) and particulate matter (PM), which are harmful to health. This is why we are launching 12 Low Emission Bus Zones (the first two are already in place) and by introducing new double decker buses from 2018 that will either be hybrid diesel-electric or zero emission. We will also be raising the entire fleet to the cleanest Euro VI engine emission standard by 2020. The Euro VI engine and its exhaust system cut NOx and PM by up to 95 and 80 per cent respectively. Where buses are significant contributors to these pollutants at street level, cleaner vehicles can make a very significant improvement to air quality. When the ultra-clean engine and its exhaust after treatment system is combined with hybrid systems, which is on most Euro VI buses, it can also reduce CO2 and fuel consumption considerably and help reduce global warming.

If this is not the information you are looking for, or if you are unable to access it for any reason, 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
Information Governance
Transport For London