TYRE development must evolve with automotive trends and following the strong sales progression of electric vehicles (EVs) in major markets, a new demand for tyres has emerged.
EVs are heavier than passenger vehicles with internal combustion engine (ICE) because of the large batteries used, and the strong and immediate torque from the electric motors on take-off would lead to premature wear of “ordinary” tyres.
The initial response from the tyre industry was to develop a tyre that could bear the higher weight of an EV and be more resistant to wear arising from strong standing acceleration.
Michelin has now shown that it could come up with a tyre that would meet both the demands of ICE vehicles and EVs.
This is the Primacy 5, the latest in the Michelin premium tyre range that is hailed as its best seller in the Asia-Pacific region (excluding China) in the after-market segment.
And like all new generation product, the Primacy 5 comes a lot improved in performance over the previous Primacy 4.
Notable achievements are 24% more mileage against rival brands (10% against Primacy 4), 8% shorter wet braking distance against rivals (13% when worn) and improvement over rolling resistance by 13%.
This is contributed to by the new tread pattern featuring the Michelin Silent Rib Gen-3 technology, a 10% increase in void ratio for the tyre treads against the previous model, optimised lateral groove edges, Functional Elastomers 3.0 featuring Michelin’s EverGrip and EverTread technologies, a high-performance rubber tread compound, among others.
Michelin says the Primacy 5’s environmental footprint is decreased by 6% that falls well in line with the Michelin Group’s “All Sustainable” strategy.
The new Primacy 5 is available in 25 sizes ranging from 16 to 19 inches and prices starting from RM477 to RM1,026.
Michelin Malaysia says the Primacy 5 tyres of 18 inches and above come with “next-level” sidewalls and full-ring velvet line.
To give us a better insight into what the new Primacy 5 is capable of, we took part in four workshops Michelin organised at the sprawling Legend Siam complex in Pattaya, Thailand.
Rolling resistance demo
To demonstrate the improved rolling resistance of the Primacy 5 and how it would benefit EVs in gaining extra range, Michelin put together a rather novel exercise.
It involved an Ora 07 and the choice for this EV was because it could free roll in Neutral unlike many EVs that go into regeneration mode when Neutral is selected.
The Ora 07 started from a ramp that was 1.5 metres high and 10 metres long and the first run was done on a rival Japanese brand.
To avoid wind drag that could compromise results, Michelin used a golf buggy towing a frame covered with plastic in front of the Ora 07 as it freewheeled along.
The first run with the rival brand had the Ora 07 coming to stop at 82.3 metres, just a few metres short of the electric charger placed there.
The car’s tyres were then changed to the Primacy 5 and the second run was carried under the same approach.
This time, the Ora 07 freewheeled to 126.4 metres, well past the charging point and boasting a difference in distance gained of 44.1 metres.
With this demo run, Michelin believes it would convince EV owners the wisdom of using the Primacy 5 in gaining a better range with its good rolling resistance.
Overall driving
We started with this exercise driving a Honda Accord e:HEV and Honda HR-V over 20km plus route that covered mainly secondary roads of varying tarmac surfaces.
The seven vehicles made available also included the new Toyota Camry that was launched in Thailand late last year, the Toyota Alphard HEV and Tesla Model 3.
The run was done with a police escort car in convoy formation and there were times when we even hit speed of above 100kph.
We started with the Accord e:HEV and were impressed by the quietness of the Primacy 5 as the road noise over the different road surfaces, including concrete ones, were barely discernible.
There were quite a few patches of rumble strips along the way and the noise generated were short and non-intrusive.
Our second drive in the HR-V was equally impressive and because this model is newer than the Accord, the improved noise insulation made the drive even quieter.
At the same time, the road impacts over the rumble strips and other road maladies such as potholes and bumps complemented the vehicle suspension system to make the ride comfortable.
Wet road experience
This session involved three new Camrys, each fitted with 215/55 R17 tyres that had tyre pressures set at the recommended 35psi (about 240kPa) front and rear.
The course included two wet corners for which we were to approach at 50kph and 60kph respectively and lift our foot off the accelerator pedal.
It might appear too low a speed but naysayers would be well advised to participate in such exercises to understand how a car could become quite a handful when taking corners on rainy days even at such low speeds.
We started with the Camry running on Primacy 5 and the steering remained rather neutral negotiating the two corners without any tyre side scrubbing noise.
Our subsequent runs in two Camrys fitted with rival Japanese brands revealed a greater tendency to understeer as the tyre side scrubbing noise revealed under more or less similar speed the respective corners were taken.
Premium comfort
This was perhaps the least exciting of the workshops as we covered the entire course under cruise control with the speed set at 35kph.
The vehicle provided were three Accords, each running on 225/50 R17 tyres that were set to the recommended 32psi (about 220kPa) front and rear.
The course featured a short slalom, two rumble strip sections and two stretches with horizontal metal rods inlaid to the road surface.
The idea was to gauge the tyre side scrub noise going through the slalom, the impacts and noise generated going over the rumble strips and metal rods.
Our experience here told us that the Primacy 5 tyre side scrub noise was the lowest of the three, the other two being Japanese brands.
We were rather tied on feeling over the rumble strips in impacts and noise against one of the Japanese tyres.
The metal rod run showed that Primacy 5’s impact was softer over the metal rods and the noise generated was short and sweet, unlike the longer wavelength pitch of the Japanese brands.
Excellent longevity
This was another exciting exercise as it involved tyres that were part worn by 2.5mm in radial tread depth.
Again, a new Camry was provided with the same tyre specification as that for the wet drive session.
Here, our comparison was only against one Japanese brand and it’s a third one against the two that were involved in the earlier workshops.
This covered a relatively shorter course with a few sharp corners and a wet loop averaging about 40kph right through.
The first run with Primacy 5 Camry turned out as expected with good turning performance on the dry section, followed by a stable wet corner performance despite the tyre’s part worn status.
We liked the quick turning performance of the Camry with the part-worn Japanese tyres although the car understeered badly when taking the wet corners.
We were timed for this drive event and the difference in times was about two seconds with the Michelin tyre providing the faster run.
