Glossary

Here’s a handy jargon buster to help you understand your vehicle’s performance on the road

aq-glossary-tokenAq – Air quality

The degree to which air in a particular place is pollution free


CH4 – Methane

An extremely potent greenhouse gas


co-glossary-tokenCO – Carbon monoxide

An odourless gas that is extremely toxic to humans. Most CO is converted to CO2 by the catalytic convertor


co2-glossary-tokenCO2 – Carbon dioxide

A greenhouse gas which stays in the atmosphere for 100 years


DfT – Department for Transport

A ministerial department with responsibility for the transport network, planning and investing in transport infrastructure in the UK


DOC – Diesel oxidation catalyst

A device to promote oxidation of several exhaust gas components by oxygen to harmless gases


DPF – Diesel particulate filter

A trap to catch bits of soot in the exhaust so it doesn’t pollute the air. It needs emptying (or burning off) periodically and this is called regeneration.


EGR – Exhaust gas recirculation

An emissions reduction technique used in ICE engines which works by recirculating a portion of an engine’s exhaust gas back to the engine cylinders.


FE – Fuel economy

The relationship between the distance travelled and fuel consumed e.g. MPG


FC – Fuel consumption

The amount of fuel a vehicle uses to travel a particular distance at a particular speed


GHF – Greenhouse gas

An excess in the amount of these gases (mainly CO2, CHCs, CH4)  resulting from human activity such as deforestation and burning fossil fuels traps infrared rays which results in global warming.


ICE – Internal combustion engine

The burning of fuel in a combustion chamber causes hot gases to expand which act directly to cause movement


l100km-glossary-tokenL/100km – Litres per 100 kilometres

The amount of fuel, measured in litres, necessary to drive 100 kilometres


LEZ – Low emission zone

A geographically defined area where the most polluting vehicles are restricted or discouraged from entering


mpg-glossary-tokenMPG – Miles per gallon

How far a car can drive using one gallon of fuel


NH3 – Ammonia

A product of combustion, it combines with NOx and SOx to form fine particulates which contribute to smog and causes respiratory problems


NO – Nitrogen monoxide

Reacts with moisture in the air to form nitrogen dioxide


NO2 – Nitrogen dioxide

A poisonous gas that is particularly harmful to people with heart and lung conditions. It also combines with Volatile Organic Compounds in the presence of sunlight to form photochemical smog.


NOx – Oxides of Nitrogen

NO and NO2 are by-products of combustion and NOx is a generic term used to describe these gases.


PEMS – Portable emissions measurement system

The equipment used to measure emissions and fuel consumption on vehicles in real-world operation rather than in a laboratory


PM – Particulate matter

A combination of small particles and droplets of liquid in the air which, if inhaled, aggravate the lungs and cause serious health effects


PM 2.5 – Fine particulate matter

Particles with a diameter of less than 2.5 micrometers which are small enough to lodge in deep lung tissue causing health problems


PM 10 – Coarse particulate matter

Particles with a diameter of less than 10 micrometers


SCR – Selective catalytic reduction

Nitrogen oxides are converted in diatomic nitrogen by injecting urea (AdBlue/DEF) into the exhaust stream


SOx – Sulphur oxides

Sulphur oxides are a by-product of burning the sulphur present in fuel. In the presence of a catalyst like NO2, it will form sulphuric acid which is a major cause of acid rain.


TfL – Transport for London

The local government organisation responsible for most aspects of London’s transport system


THCs – Total hydrocarbons

A term to describe compounds which contain hydrogen and carbon. One source is from the burning of fossil fuels during combustion.


ULEZ – Ultra low emission zone

An area within which all cars, motorcycles, vans, minibuses, buses, coaches and heavy goods vehicles will need to meet exhaust emission standards or pay a daily charge to travel


VED – Vehicle excise duty

A tax payable for most types of vehicle which are used or parked on public highways


VOCs – Volatile organic compounds

Organic compounds that easily become vapours or gases


Menu