since 1976
since 1976
By Lee Pang Seng
THE advent of EVs (electric vehicles) made new demands on tyres as they need to perform well under a heavier vehicle load and higher stress during strong initial acceleration. The former has to do with the huge battery under the floorboard and the latter comes from the high torque output that is immediately applied to the tyres when one steps on the accelerator.
The strong initial torque is the reason why despite the heavier kerb weight of the vehicle, one could feel the immediate get-up-and-go acceleration with EVs. Depending on the electric motors used, the torque output could go even above 1000Nm as in the case of the latest Porsche Macan Turbo EV (1130Nm).
This high torque output puts a lot of stress on the drive tyres during acceleration as they must grip the road without spinning. Doing hard acceleration often might even lead to quick wear and tear on the tyres because of the frequent stress they are put to. As such, tyre makers had to come up with tougher tyres that cater to the specific needs of EVs.
As a step forward, Michelin decided to combine the needs of EVs and ICE (internal combustion engine) vehicles when it got down to developing the Primacy 5. And following its launch of the Primacy 5 last year, it reflects the French tyremaker’s confidence of its latest product meeting both power propulsion needs handsomely.
As usual, the development targets are mostly approached along similar lines as in comfort, safety and longevity with the new objective in being suitable for EVs. In the area of comfort, Michelin says the Primacy 5 is tops in silence and comfort while the safety aspects, mainly on wet road surfaces, is an eight per cent shorter braking distance over Primacy 4 and 13-per cent shorter when part worn.
Michelin also says the Primacy 5 is a more durable tyre that offers an improvement of 24 per cent in mileage, which means you get to keep driving longer on this latest tyre product. Another relevant note is that the Primacy 5 has a 13-per cent lower rolling resistance, which means there is less friction acting on the tyre when coasting. Michelin believes this would mean a longer battery range for EVs.
The comfort factor is made possible with the Silent Rib Gen-3 tread design that sees multi zoning void tuning on the tread area for a smooth ride. The intermediate tread ribs are also designed to reduce vibration, which Michelin says gives ‘great noise’ reduction for a quieter and comfortable drive and ride.
On closer inspection of the Primacy 5, one could see an extension of the Silent Rib Gen-3 technology to the three central rib treads from the shoulder rib areas. The aim was to limit repetitive noise and reduce noise sources. Tests conducted by TUV Rheinland Thailand Ltd in December last year showed that the Primacy 5 was clearly quieter running against a rival brand and a lot more comfortable too.
Another positive aspect of the Primacy 5 tread area is that the Michelin Maxtouch technology allowed it to maximise contact on the road surface. It does this by ‘evenly distributing’ the forces of acceleration, braking and cornering that would deliver a longer tread life without compromising on safety. A test conducted by Dekra Test Center in France in July 2024 showed that the Primacy 5, on average, lasted 24-per cent longer than other premium brands. Compared to the Primacy 4, the tread life improvement is 10 per cent.
All these improvements are also due to the tyre compound that features the Functional Elastomers 3.0, comprising the Michelin EverGrip and EverTread technologies. Michelin says this allowed a performance optimised sculpture and new long-lasting tread pattern that optimises water evacuation. ‘Excellent’ wet braking performance is one benefit. Against the Primacy 4ST, the long-lasting wet sculpture sees the void ratio being increased above 10 per cent when new and worn.
Here too, tests conducted by TUV Rheinland Thailand Ltd in November 2024 revealed positive results in 80-0km/h braking on wet road surfaces. The vehicle used was a Honda Accord e:HEV fitted with 225/50 R17 tyres, both Michelin and rival tyre brands. With new tyres, the Primacy 5 came to a stop 2.2 metres shorter against rival brands. For the worn tyre tests, the Primacy 5’s performance was even better stopping 4.3 metres shorter!
Michelin Malaysia says the new Primacy 5 is available in 25 sizes that range from 16 to 19 inches with prices starting from RM477 to RM1026. However, the Primacy 5 tyres of 18 inches and above are more visually attractive as they come with ‘next-level’ sidewalls and full-ring velvet line.
We were given the opportunity to experience all the new benefits of the Primacy 5 hands-on in a series of ‘workshops’. Comparisons with three Japanese tyre brands in similar cars were organised to highlight the differences in tyre performance over different scenarios. This exercise was conducted under controlled conditions at the sprawling Legend Siam complex in Pattaya, Thailand.
Rolling success
Before we were to begin the first of our four workshops, Michelin wanted to impress upon us the benefits of the Primacy 5’s lower rolling resistance in a way that the results could be clearly observed. And what a better way to do it than with a vehicle of the times, an electric vehicle (EV).
A sporty looking GWM Ora 7 was chosen for the demo run and Michelin explained its choice as been an EV that could coast or freewheel on Neutral, like an ICE vehicle. Many EVs, such as the Tesla range, would go into regeneration mode when Neutral is selected and couldn’t coast or freewheel. Similarly, the Ora 7 could also be pushed when Neutral is selected.
The Ora 7 started from a ramp that was 1.5-metres high with a sloping ramp that was 10 metres long. To prevent wind drag affecting the coasting movement of the Ora 7, a golf buggy was used to tow a covered moving frame that shielded the Ora 7 from gusts of wind as it coasted along. It was certainly a practical move.
The Ora 7’s first run was done on a Japanese brand tyre; this sporty GWM car comes with 235/50 R18 tyres as standard. As such, the same tyre size was chosen for the Japanese brand. The tyre pressure was set at the recommended 35psi (240kPa) and this was all clearly shown on the live video footage shot during the event.
A dummy EV charger was set along the course and the idea was to show if the Ora 07 could coast to the charger should the battery run flat. With the Japanese brand tyres, the Ora 7 coasted to 82.3 metres before coming to a stop, just a few metres short of where the ‘charger’ was.
The tyres were then changed to the Michelin Primacy 5, with all the action captured by video cameras and telecast to the TV flat screen in the media tent. We also noted that the tyre pressures were set to the same 35psi (240kPa) and the same driver drove the Ora 07 to the start ramp.
We expected the Ora 07 to coast further on the Primacy 5 with its improved rolling resistance but the distance that it covered was truly impressive. It allowed the Ora 07 to cover 124.6 metres before coming to a stop. This was 44.1 metres further than the distance covered by the rival tyre brand. It fully convinced us that an EV could enjoy greater battery range running on the Primacy 5 tyres.
Public road experience
Our first workshop was to appraise the Primacy 5 tyres in a variety of cars on more than 20 kilometres of public roads in Pattaya South. We were supposed to go two to a vehicle but for some reason we had the Honda Accord e:HEV RS to ourselves. The other vehicles provided for the drive were a new model Toyota Camry, a previous model Camry, Honda HR-V, Tesla Model 3, Toyota Alphard HEV and a second Accord e:HEV RS.
Each was fitted with Michelin Primacy 5 tyres according to the recommended sizes for the respective vehicle. The drive was conducted in a convoy format with a Thai Police Car to lead the pace. While the road speed was generally within the regulated limit, we did drive above 100km/h along a few low traffic stretches.
The roads covered were varied in tarmac surfaces, including concrete ones, and there was the fair share of rumble strips, road dips, bumps and other road irregularities along the route. We immediately found the Primacy 5 a quiet running tyre as it covered all these road surfaces with the least of noise, even the concrete surfaces that tend to generate road roar.
We were equally happy to drive the Accord e:HEV RS over bumps and rumble strips as these Michelin tyres complemented the car’s suspension in soaking up the road impacts for a comfortable drive. The noise generated over the rumble strips was hardly discernible and we barely felt much of the repeated impacts that serve as a sort of warning to slow down or be cautious.
At the midway point where a driver change was to be made, we changed to a different vehicle instead. Although we would love to experience the Primacy 5 in an EV like the Tesla Model 3, we only found a willing ‘barter’ with the driver of a Honda HR-V. It was still a different experience as we had gone from a car to an SUV (sport utility vehicle).
The silent drive feeling remained constant but we found the HR-V more comfortable and quieter when running over rumble strips. As the HR-V is a newer model over the Accord, we believe the improved suspension system in the former complemented the Primacy 5 tyres better for an even more premium ride experience.
Mastery on wet roads
The second experience was to gauge the Primacy 5’s improved grip on wet road surfaces. To make it more interesting, Michelin arranged for us to compare the Primacy 5 against two Japanese tyre brands over a set course with two corners that were kept constantly wet.
Three Toyota Camrys were provided and each was fitted with 215/55 R17 tyres that were set to the recommended pressure of 35psi (about 240kPa). We were to drive each Camry in succession to experience how each tyre brand would perform taking to the two wet corners. We were to approach each corner at speeds of 50km/h and 60km/h respectively and then take our foot off the accelerator pedal on entering the corner.
If you think the speed is way too low, you would be surprised at how unbalanced a car could be when taking corners on wet roads at such seemingly low speed. We started the run in a Camry fitted with the Michelin Primacy 5 tyres and its better water dispersal qualities and tread pattern gave us a confident feeling of steering direction and car control. There was also no tyre side scrubbing sound as it coasted through each successive corner, which meant the Primacy 5 tyres were keeping the Camry to its chosen cornering line without any drama.
We were a bit too ambitious when approaching the second corner, entering it at slightly above 70km/h. That stretched the Primacy 5’s grip limits somewhat and we understeered off the track a bit before steering back onto the chosen path. We made a second run at the suggested speed of 60km/h and did a cleaner and less dramatic drive through the wet corner.
The subsequent runs in the Japanese brand tyres revealed a tyre side scrubbing sound, which meant the tyres were not gripping as firmly as it should on the wet road surfaces and were sliding. As such, the Camry wanted to go straight as in an understeer and we were close to exiting the track at the respective corners. Taken at more or less the same speed but with different car reaction.
There was a dry course before the wet corner section where we could feel the respective tyre’s performance through the corners and an S-bend. We felt that one of the Japanese tyre brands had a sharper turn-in when taking the dry corners, which suggested its sporty orientation. While that for the Primacy 5 wasn’t too bad, we were reminded that this Michelin tyre was targeted at premium car driving performance.
Comfort drive
Our third workshop was to gauge the Primacy 5 on its ability to perform quietly and comfortably. It was also the slowest drive experience of the four exercises as we covered the entire course in cruise control with the speed set at 35km/h. This included a slalom run, driving over two rumble strip sections and two final stretches with metal rods laid across the road surface.
Here, three Honda Accords were provided with each car fitted with 225/70 R17 tyres and the pressures were set to the recommended 32psi or 220kPa. Again, we were to compare the Primacy 5 against two Japanese tyre brands, similar to those featured in the wet corner drive exercise.
As we took to the slalom course in the Accord fitted with the Prinacy 5, there was no tyre side scrubbing noise as expected to make the drive pleasantly quiet and comfortable. Doing so with the Honda running on the two Japanese tyre brands, we could hear the side scrubbing noise. While one of the Japanese tyres sounded quieter than the other, both were still relatively noisier against the Michelin.
The rumble strip section brought out a different experience; we felt that one of the Japanese tyre brands was about the same in impact absorption and noise generation as the Primacy 5. Another curiosity was that it was not as quietly taken as the Accord we drove on public roads earlier, albeit at higher road speeds. The explanation was that at the lower speeds that the rumble strips were taken, the sound pitch or wavelength tended to be longer and was thus higher in note.
On the stretches with the iron rods, the Primacy 5 ran over them with quick ‘thuds’ and not prolonged ones like those from the Japanese tyre brands. The impact noise generated had shorter wavelengths while the sound made by the rival brands had a longer pitch. That meant we heard more of the noise generated by the Japanese tyres than that from the Primacy 5.
Longevity test
Michelin believes that its tyres should perform up to expectations even when they are part worn. This approach underlined its development targets and to prove that its Primacy 5 would perform well when part worn, the last exercise involved tyres that were worn to 2.5mm remaining tread depth.
Two Toyota Camrys were provided for this event and the comparison was against a third Japanese tyre brand, unlike the two used in the wet corner and comfort workshops. The tyres were of 215/55 R17 size and the pressure was similarly set at 35psi (240kPa).
The course featured a few sharp dry corners and two tight loops that were kept constantly wet. The recommended speed was 40km/h and if you think that’s too slow, you should take part in such exercises to experience how violent a car’s reaction could be even at such low speeds.
We were comfortable driving the Camry with Primacy tyres through the tight corners and negotiating the wet tight loops confidently. For the Camry with the Japanese tyres, we liked the quick turn-in when taking the dry tight corners – again revealing the tyre’s sporty orientation – but for the wet tight loops, it was a different story.
While the first loop was taken with some confidence, the second one had us understeering out of the track and we had to steer the Camry back on course. We were timed for the respective runs and our drive with the Primacy 5 Camry through the course was two seconds quicker as we didn’t lose time trying to regain control of the car at the wet tight loops.
