Do eco-tyres really save fuel? Yokohama’s BluEarth ES32 certainly seem to prove so
There are many ways to be more fuel efficient.
For the majority of us, the most cost-effective way, bar none, is to change your driving behaviour, which can result in dramatic reductions in fuel used: One participant in a Shell fuel-efficiency event improved her fuel efficiency by 54 percent through driving style modifications alone.
Generally, add-ons or devices like fuel ‘chargers’ with outlandish claims won’t really help your car when it comes to saving fuel. If we’re talking about a vehicle you already own, your money is best spent on maintenance – or tyres.
Eco-tyres, or green tyres, help a car go further on less fuel because they’re designed with lower rolling resistance. Yokohama’s BluEarth range of tyres is a prime example, and we had the chance to put the latest model, the BluEarth ES32, to the test on Singapore’s roads.
The ES32, as we covered in our launch story earlier this year, is a mainstream eco tyre aimed at anything from small hatchbacks to large family cars. Compared to Yokohama’s existing BluEarth AE50, it “puts an emphasis on handling and quietness over the ES32, which prioritises wet handling, ride comfort, endurance and fuel efficiency.”
Having longevity, improved grip and handling, but with less rolling resistance seems contradictory, but that’s where the very complex science of tyre compounds and construction come in.
Certain elements define a tyre’s performance (see our glossary at the end for more information). For example carbon black adds wear resistance and strength, while silica improves wet grip.
But how the components are mixed is just as important too. The ES32 uses the brand’s ‘nano blend technology’, which simply means that it’s able to incorporate materials or substances at a very small level so they work together on an even better level.
In this case, Yokohama’s ‘Blend Polymer’ is one key ingredient. If it sounds unspecific, that’s because tyre companies usually don’t specify what exactly is in their tyres – it’s a trade secret and millions of R&D dollars have gone into them.
Blend Polymer adds fuel efficiency, while silica and orange oil are also in the tyre compound, which, Yokohama says, helps achieve better wet/dry drip plus longevity at the same time. An added bonus for eco-minded consumers is that the orange oil used it extracted from orange peels, so it helps minimise waste and is environmentally-friendly too.
So after all that science-ing, do the tyres really work? Our initial impressions say yes.
We had the tyres installed on our test mule, a 2014 Volkswagen Golf 1.4 TSI. While the Golf is one of the more frugal hatchbacks around, its Michelin Energy XM2 stock rubber was getting old after three years, albeit just with 30,000km mileage, and they never exhibited generous grip to begin with.
The first impression from the ES32’s was a much more direct feeling of contact with the road and a little more stiffness as well, which translated to slightly harsher feeling over small bumps. That sounds like a negative, but it’s actually part and parcel of a fresh set of tyres: Age and wear makes tyre sidewalls more pliable over time, so new tyres always feel springier.
The VW Golf 1.4 is already a very frugal hatch – the ES32 tyres just make it even easier to get scores like this
As for efficiency, the ES32’s are already contributing to getting the Golf back near its original efficiency figures. Before changing tyres, we were averaging around 5.0 to 5.5L/100km on longer highway routes, and 6.5 to 7.0L/100km in slower urban traffic. The ES32’s have made it consistently easy to score less than 5.0L/100km on the highway and towards the lower 6.0L/100km figures in town.
Obviously these are not super-scientific back-to-back comparison results, but our own observations from the same car with the same driver, driving style and driving mode. Naturally, your own mileage may vary.
Brand new tyres of any sort will probably help fuel efficiency, but green tyres will do it better
Another caveat is that worn tyres always have more rolling resistance than fresh ones, but of course a set of eco-tyres like the ES32 will make the fuel efficiency improvement much more obvious than say, track-focused semi-slicks.
These initial impressions of the ES32 come from 500km of driving in Singapore, so a more comprehensive review exploring Yokohama’s claim of improved wet grip and handling will follow later this year.
Yokohama BluEarth ES32
Price: $130 per tyres, as fitted, plus tyre rotation
Contact: Find your nearest Yokohama dealer at http://yhi.com.sg/dealer
Carbon black – A petroleum byproduct used in tyres as a reinforcing and filling agent. Without it, tyres would be the colour of latex, or pale beige.
Compound – The complex mix of chemicals and materials that make up the actual ‘rubber’ which touches to road.
Latex – Rubber as we know it. Latex is harvested from rubber trees, although lots of the rubber in modern tyres is also synthetic latex.
Rolling resistance – The energy lost to the friction and movement of the tyre itself that would otherwise be translated into forward movement. Basically, what stops a tyre from rolling indefinitely.
Silica – Silicon dioxide, a white powder, is added to tyre compounds to bolster wet performance and to reduce rolling resistance.
Tread – Often mistaken as ‘thread’, tread is the pattern cut or moulded on the face of the tyre compound. Tread design is very complex, and affects all aspects of tyre performance.