The Diesel Debate - Which Fuel is Right for Me?

Choosing your next Honda

There has been much debate about diesel cars and their emissions, both CO2, NOx and particulates. In order to make a decision on your next car, you need to understand these emission types and how they relate to the sort of driving you do:

  • CO2 - contributes to global warning and is a threat to the planet
  • NOx and particulates - affect local air quality and are an urban challenge

Diesel cars produce less CO2 than Petrol, which is beneficial for our fight against global warming, but petrol cars produce less NOx and particulates, which is beneficial for tackling local air quality. Therefore we believe that every driver should purchase the car that works best for their journey, profile and lifestyle:

  • Think Diesel - if you drive long distances on the motorway or are generally a high mileage driver
  • Think Petrol - if you live in a city and mainly do short journeys inside the city or are generally a low mileage driver

Key diesel facts

  • Diesel engines have improved
  • Diesel cars produce less CO2
  • Cars are not the biggest contributors to air pollution
  • Diesel cars now have very advanced filter systems
  • Euro-6 diesels permitted by Clear Air Zones
  • No plans to increase VED (Road Tax) on diesels
  • New Real Driving Emissions test

Diesel facts in detail

Diesel engines have improved

Cars made after 2015 are Euro 6 compliant and are required to emit around half the NOx and particulates of a car made before 2009.

Diesel cars produce less CO2

Diesel cars are still more fuel efficient than their petrol equivalents. They use less fuel and emit on average 20% less CO2.

Cars are not the biggest contributors to air pollution

In London, diesel cars account for 11% of roadside NOx and 7% for petrol cars. It is a similar position for particulates.

Diesel cars now have very advanced filter systems

Many diesel cars now have diesel particulate filters and selective catalytic reduction systems, reducing emissions.

Euro-6 diesels permitted by Clear Air Zones

Clean Air Zones have proposed levels which determine what type of vehicles are charged to enter the Clean Air Zone. Diesel cars will only be charged in the strictest Clean Air Zone and only if they are pre-Euro 6 and manufactured before 2015.

No plans to increase VED (Road Tax) on diesels

There are currently no plans to increase VED (road tax) on diesel cars1, and should there be, it would not be retrospectively applied.

New Real Driving Emissions test

By September 2018 all new cars will have to pass a new more stringent Real Driving Emissions test before being sold.

Further information


  1. To the best of our knowledge at the time of writing.