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Click the links below to download a pdf of the results

Euro 5 & 6 diesel vehicles

Euro 5 & 6 petrol vehicles

Euro 5 & 6 hybrid vehicles

The EQUA Carbon Monoxide Index

What is the issue?

Potentially fatal for humans as well as damaging to the environment, carbon monoxide is generally considered a problem primarily confined to petrol vehicles. Regulations to control CO emissions distinguish between the fuel types, with petrol vehicles legally allowed to emit twice as much as diesel vehicles. The EQUA CO Index reveals whether the statutory requirements are being met in real-world operation.

How the EQUA CO Index helps

The EQUA CO Index awards a universal rating regardless of fuel type to allow comparisons between vehicles. Petrol vehicles tested by Emissions Analytics on the road need to achieve a C-rating or better to match the requirements of the 1.0g/km regulated limit. Diesel vehicles have to meet the more stringent 0.5g/km limit which is identified as an A-rating or above on the EQUA CO Index.

The EQUA Index is the definitive guide to vehicle emissions on the road, powered by Emissions Analytics, the independent testing and data analysis experts.

Use the table above to identify which cars are legally compliant in real-world operation from the extremely clean A++ rated models to those emitting many times more than the law allows.

Ratings Explained

Rating Lower bound1 Upper bound2
A++ 0.00 0.125 Euro 4-6 diesel
A+ 0.125 0.25 Euro 4-6 diesel
A 0.25 0.50 Euro 4-6 diesel
B 0.50 0.64 Euro 3 diesel
C 0.64 1.00 Euro 2 diesel, Euro 4-6 petrol 60% more than current petrol limit, ~x3 current
D 1.00 1.60 Diesel limit
E 1.60 2.20 Euro 2 petrol
F 2.20 2.72 Euro 1 diesel, Euro 1 petrol
G 2.72 5.44 Up to double Euro 1
H 5.44  – More than double Euro 1
Units: g/km, 1 exclusive, 2 inclusive