Many drivers ask if there is a link between a tyre which has low rolling resistance and its grip.
In years gone by, this trade-off was certainly true. But with today’s technology, compounds and construction, we can have the best of both worlds – tyres which have low resistance and still plenty of grip for accelerating, braking and cornering.
Here we look at what rolling resistance means, how it works and some of the tyres which deliver the best results.
What does low rolling resistance mean and how does it affect my vehicle?
When a tyre rotates over a road surface, there is friction between the rubber and the tarmac. This is the basic ingredient of grip. Without any friction, the tyre would be like a bar of wet soap, slippery and with zero traction.
In that sense, rolling resistance is a driver’s friend. However, it comes at a cost. To overcome that friction and keep the tyre moving, it must take power from the engine. The upshot of this means higher fuel consumption.
It will surprise many drivers, but even with a properly inflated tyre, around 20% of a car’s mpg figure is solely down to the power needed for it to work. Perhaps as much as 15% is accounted for by the rolling resistance. The rest is by the heat generated and the movement in the tread and sidewalls.
How do I find out what a tyre’s rolling resistance is?
All new tyres sold carry an EU label which grades its wet weather grip, fuel economy and noise from A to G. A being the best and G being the worst.
Rolling resistance is included in the fuel economy measure and is shown with the emblem of a petrol pump. A tyre with a ‘B’ rating would deliver good miles per gallon.
As a rule of thumb, the difference between an A rating and a G can be around 8%, which over the lifetime of a tyre can have a big impact on your running costs.
Can I get tyres which deliver good results for both?
The answer is yes, you can. Tyre manufacturers have spent fortunes developing tyres which meet both targets.
Take the Goodyear EfficientGrip Performance, for example. The 205/55 R16 W (94) scores an A for wet grip and fuel economy. Likewise, the Continental Eco Contact 6 has an A rating in both. Pirelli’s P7 Blue set the standard when it was launched several years ago because it was the first to achieve a double A. Many of its treads still do today.
There are lots more to choose from, but the basic message is that it is possible to find a `best-of-both-worlds’ tyre which delivers good fuel economy and good grip. What’s more, you don’t have to go for one of the bigger brands to find these tyres either. For example, the Falken ZE310 scores A for wet grip and C for fuel economy.
The EU Label
Given the need for cars and vans to be more fuel efficient and less polluting, tyre manufacturers have invested plenty in making their products greener. The gains have come from the construction of the tyre and the chemical make-up of the rubber compound. They have cut the amount of heat generated, used polymers to reduce the basic resistance, and improve the rubber compound at a molecular level.
Given this, you may be wondering why all tyres don’t get good grades. The reason is that some are optimised for more grip – usually the tyres targeted at high performance vehicles. Likewise, some eco-tyres are engineered for maximum fuel economy, but at the expense of grip.
Today, the good news is that there are plenty of tyres which deliver grip without wasting engine power. To find out more about the best tyres for your vehicle, call our expert team today and we’ll be happy to help.