2019 Mazda 3 to adopt torsion beam rear suspension for refinement

The fourth-generation Mazda3 is set to use a torsion beam rear suspension when revealed in production form in 2019.

Teased in both bare chassis and mechanical prototype forms at Mazda's 2017 Global Tech Forum in Germany last week, all examples on show were fitted with the relatively simple semi-independent rear end setup.

This apparent technological backward step follows the use of complex multilink independent rear suspension designs for all three Mazda3 generations to date.

Using multilink in favour of torsion beam has helped underpin Mazda's Zoom Zoom marketing slogan and give the Mazda3 an outright dynamic upper hand over global rivals like the Toyota Corolla, Peugeot 308, Renault Megane, and previous versions of the Honda Civic hatch.

The torsion beam looks simple and cheap, but Mazda promises a net gain.

Speaking with CarsGuide in Germany, Mazda platform development boss Hiroyuki Matsumoto explained that the torsion beam's simplicity will reduce noise, vibration and harshness (NVH) - an acknowledged weak point for the brand of late - transmitted from the road to the cabin.

A torsion beam setup connects the rear wheels with a single steel subframe that twists via a transverse beam to allow the wheels to react to bumps semi-independently.

Conversely, Matsumoto-san explained that a multilink's abundance of moving parts and associated pivot points are a breeding ground for stray vibration that can find its way into the cabin.

Therefore, a torsion beam's more simple input to the car's sprung mass (body), is easier to fine tune across a variety of road surfaces.

Mazda currently only uses the torsion beam layout on smaller and cheaper models like the Mazda2 and CX-3.

Matsumoto-san explained that a new torsion beam design was key for achieving his team's refinement and dynamic targets.

The prototype setup previewed in Germany shows broadening of the transverse beam at either end, to strengthen the area near each wheel and help minimise alignment distortion through the suspension's vertical travel.

The front suspension will continue as a strut arrangement, but with revised architecture that sees control arms lengthened and geometry revised to also help reduce NVH.

Another key benefit will be expanded rear seat space because of the inherent compactness of the torsion beam design, without lenghthening the wheelbase.

The 2019 Mazda3's suspension will be incorporated into the first use of the brand's second generation SkyActiv body and chassis, branded SkyActiv-X.

Along with an ongoing dedication for boosting efficiency from well-to-wheel, SkyActiv-X development is also targeting refinement gains by harmonising the interaction of all components between the tyres and driver.

The jewel in the SkyActiv-X crown, however, is the world-first application of combustion ignition to boost efficiency and power delivery from its also-supercharged petrol engine.

Would you prefer outright dynamics over refinement and value? Tell us what you think in the comments below.