Low rolling resistance tyres proven to reduce fuel use
Low rolling resistance tyres could save New Zealand over $100 million in fuel a year, according to the Energy Efficiency and Conservation Authority (EECA).
Low rolling resistance tyres improve a car's overall fuel efficiency by reducing the friction a tyre has to overcome when it rolls, meaning less fuel is required to travel the same distance. International research has shown fitting them on your car could translate into fuel efficiency savings of 3% - around 40 litres of fuel a year for the average New Zealand car.
New Zealand roads, however, are constructed using different materials and there have been some questions over whether low rolling resistance tyres could perform to the same standards here.
"As the coarse chipseal on a lot of New Zealand roads is quite different to the asphalt and concrete surfaces widely used in other countries, we decided to investigate whether low rolling resistance tyres could also provide fuel saving benefits on New Zealand roads", says EECA Transport Manager Liz Yeaman.
EECA engaged independent testing laboratory OPUS Central Laboratories to trial the relative on-road performance of low rolling resistance tyres and standard tyres.
Specifically, the rolling resistance and wet emergency braking stopping distance of two makes of low rolling resistance tyres were measured against two makes of standard tyres.
"Using a ‘coastdown' method of testing, which measures the distance taken for a car to coast to a complete stop when fitted with different tyres, the research was able to confirm that low rolling resistance tyres can make fuel savings possible on fine and coarse textured New Zealand chipseal road surfaces compared with standard tyres", says Ms Yeaman.
"If we consider that international research shows these fuel savings equate to around a 3% improvement in overall fuel efficiency, fitting even half of all light petrol and diesel vehicles in New Zealand with low rolling resistance tyres could mean savings of about 55 million litres, or $114 million worth of fuel a year¹."
Ms Yeaman says concerns that low rolling resistance could compromise safety were not borne out, with only a slight trade-off between reduced rolling resistance and wet emergency braking stopping distance on the tested coarse chipseal surface only noticeable when going 70km/h.
Low rolling resistance tyres are widely available at most tyre retailers, and cost around $20 more per tyre than their standard equivalent. Any concerns about low rolling resistance tyres can be discussed with tyre retailers.
¹ 55 million litres/$114 million is 1.5 million cars travelling 12,730 kms/year, fuel efficiency of about 10l/100km, with petrol at $2.15/litre (petrol) and diesel at $1.65/litre (diesel).