New Benz A-Class hybrid drove torsion beam

MERCEDES-BENZ says that future proofing for electrification was one of the key reasons why a torsion beam rear suspension set-up was developed for the new A-Class hatchback due in Australia in August.

Daimler AG overall development engineer for compact cars Frank Weinert revealed that while saving weight and manufacturing costs were factors in creating a lighter and cheaper alternative to the multi-link independent rear suspension (IRS) set-up used in the outgoing A-Class, the need to package the hardware associated with the coming ‘EQ’ petrol-electric hybrid models was the leading motivator.

“Yes, electrification drove the twist beam (as torsion beam is known as in Daimler-speak) development for the new A-Class,” he told GoAuto at the launch of the fourth-generation A-Class in Croatia last week. “As well as being lighter, it takes up less space than the multi-link axle, which is very important in a small car.”While Mr Weinert would not confirm the existence of a petrol-electric A-Class, it is believed to be the mooted A250e that is expected to debut sometime next year for a 2020 launch in Australia under the burgeoning EQ electrification program that will also include a host of other variants.

The latter is all but a certainty for our market given Mercedes-Benz Australia/Pacific has decided to pass on the A180d turbo-diesel that is also part of the new A-Class family in Europe.

For now, all standard-specification front-wheel drive A200s, as well as the A180 base hatch arriving at the end of this year, will have a torsion beam in place of their corresponding predecessors’ multi-link arrangement, although IRS will be available optionally with adaptive dampers included as part of a dynamic driving package for an as-yet undisclosed premium.

Meanwhile, the coming A250 4Matic all-wheel drive also due in December will have IRS as standard, as will the AMG A35 and AMG A45 4Matics out during next year.

Mr Weinert added that the decision to include the torsion beam was made right from the start of the W177-series A-Class program four years ago, and not later on in the program, to ensure that the car could be manufactured as efficiently as possible with both suspension varieties.

“The twist beam was in from the beginning, since it was necessary for it and the multi-link to share the same mounting points (in the body),” he said. “The structure is the same in the underbody as a result.”As GoAuto reported in February, improved comfort and quietness were further incentives to usher in the torsion beam, with Mr Weinert reiterating this by saying that Mercedes-Benz explored many innovations in order to achieve its goals, and that it would not take a backward step if ditching IRS meant inferior refinement and dynamics.

“The new twist beam had to be demonstrably better than the old multi-link arrangement,” he claimed. “We worked very hard in achieving our goals of greater agility and comfort while reducing NVH (noise, vibration and harshness) and carbon dioxide emissions… and we did this with the use of new bushings and other materials… and we worked hard on developing new damper rates and damper connections to the body.”Although Mr Weinert declined to mention which competitor models offering torsion beam rear suspension served as benchmarks, he did not specifically rule any Volkswagen Group models such as the base Audi A3 and Volkswagen Golf.

“Let’s just say we looked at most of the rivals,” he said.