Tyres with high wet grip performance (A or B graded) have shorter braking distances on wet roads and are, therefore, safer in the rain. As with fuel efficiency, the D grade isn’t used and there are no plans to use G.
Tyres account for up to 20% of your vehicle’s fuel consumption so, if you want to get more miles per tank of fuel, you should choose tyres with a high fuel efficiency rating. You will also lower your CO2 emissions. It comes down to rolling resistance i.e. the energy lost when a tyre is moving. The lower the rolling resistance, the less energy is lost and the lower your fuel consumption and CO2 emissions. The difference between an A-rated tyre and a G-rated tyre could be as much as 6 litres per 625 miles.
This is the external noise made by the tyre and is measured in decibels. The more filled bars shown on the label, the louder the tyres.