Michelin Primacy 3 ST vs 4 ST - Which Is Better? [Test Data]

Fuel Efficiency

The US Department of Energy estimates that around 25% of the fuel consumption of a vehicle is attributable to the tyres. That's a lot, and it means that choosing fuel efficient tyres can save you quite a bit of money.

The Primacy 3 ST tyres rank a C on a scale of A to E in the official fuel efficiency tests carried out by the EU (they call these rolling resistance tests).

The Primacy 4 ST tyres also get a grade of C.

As their fuel efficiency grade is the same, expect negligible differences in fuel consumption between them.

Here's a graph comparing the Primacy 3 ST and Primacy 4 ST tyres for fuel efficiency (1 = Grade E, 5 = Grade A).

Grip & Handling

We'll now take a look at how these tyres compare in terms of grip and handling.

A good measure of this is 'wet grip', which is an indication of how well the tyres will allow the vehicle to come to a stop in wet conditions.

The Primacy 3 ST tyres rank a B on a scale of A to E in the official fuel tests carried out by the EU.

The Primacy 4 ST tyres, on the other hand, get a grade of B.

As their wet grip grade is the same, expect negligible differences in terms of braking distance.

Here's a graph comparing the Primacy 3 ST and Primacy 4 ST tyres for wet grip (1 = Grade E, 5 = Grade A).

Noise

Another key factor to consider when choosing a tyre is road noise. Once you're over about 40 km/h, the dominant source of noise you hear is from the contact of your tyres on the road.

There is a surprisingly wide variation in the amount of noise each tyre makes.

The Primacy 3 ST tyres produce 71.0 dB of road noise, which corresponds to a rank of B on a scale of A to C in the standardised testing done by the EU.

On the other hand, the Primacy 4 ST tyres produce 68.8 dB of road noise, which means a grade of B.

As their noise grade is the same, don't expect many differences in terms of cabin noise.

Here's a visual representation of how the Primacy 3 ST and Primacy 4 ST tyres stack up for noise (1 = Grade C, 3 = Grade A).

The Primacy 3 ST tyres have a treadwear rating of 340, which means that they would last 3.4 times longer than a tyre with a rating of 100. There's no treadwear data available for the Primacy 3 ST tyres.

The Primacy 4 ST tyres have a traction grade of A (on a scale of AA, A, B, C). There's no UTQG traction grading data available for the Primacy 3 ST tyres.

The Primacy 4 ST tyres have a temperature resistance grade of A (on a scale of A, B, C). There's no UTQG temperature resistance grading data available for the Primacy 3 ST tyres.

For fuel efficiency, Primacy 3 ST score a grade of C, which is more or less average. Primacy 4 ST end up with a grade of C, which is more or less average.

More important is the wet grip, which gives you an indication of their traction and handling. In this regard, both the Primacy 3 ST and the Primacy 4 ST get a score of B, which is above average.

More important is the wet grip, which gives you an indication of their traction and handling. In this regard, Primacy 3 ST get a score of B, which is about typical. Primacy 4 ST end up with a grade of B, which is about typical.