BMW has given journalists a first technical briefing on the next-generation 3 Series at its Miramas proving ground in France, revealing that the combustion-powered saloon will share its central driving dynamics software with the company’s electric Neue Klasse models. The new architecture, called Heart of Joy, uses a single central computer running one software stack to coordinate braking, stability control, traction, the rear differential and steering, replacing the separate control units used in previous generations.
The move marks a significant shift in how BMW develops its petrol and hybrid models. In electric vehicles, the software can shift torque between axles almost instantly and use recuperation to decelerate the car at up to approximately 0.4g, covering roughly 98 percent of everyday braking without engaging the friction brakes. Combustion engines cannot replicate that behaviour because torque delivery takes hundreds of milliseconds to build, so the same central computer in the 320 and M350 instead coordinates brake intervention, stability and traction control, the electronically controlled rear differential and steering, using one software stack with no communication delay between separate control units.
BMW describes the hardware housing as identical to the electric-vehicle version, with a different processor and software developed specifically for combustion and plug-in hybrid powertrains. The company says this is the 10th generation of the software, developed entirely in-house. New for this generation is the 6D Motion Observer, a sensor cluster measuring lateral, vertical and longitudinal acceleration along with roll, pitch and yaw, giving the software a continuous, precise measurement of understeer or oversteer conditions independent of driver input.
The technical briefing also detailed the chassis hardware for the base 320 and the range-topping M350 xDrive. The base 320 rides on an all-new body with revised global stiffness targets. Front track width increases by 40mm and rear track width by 32mm over the outgoing model, while the wheelbase grows by 90mm and wheel diameter increases to 680mm. The front axle retains a double-joint MacPherson strut layout with revised kinematics for increased trail, slightly reduced camber and softer spring rates, fitted with Hydraulic Rebound Stop dampers, a technology BMW says it carried over from the Neue Klasse iX3.
Other front-axle changes include a stiffer axle carrier, a new shear panel connecting the shock tower to the firewall, and revised anti-roll bar bushings. The rear uses a five-link axle with the same Hydraulic Rebound Stop dampers, a stiffer camber arm, revised elastokinematics and increased stiffness at the top mount-to-body connection, which BMW says is intended to reduce the delay between steering input and damper engagement during body roll. An Adaptive Suspension is available as an option on all variants, always paired with Sport Steering and offering two drive modes, Personal and Sport.
The M350 xDrive is powered by a 3.0-liter BMW TwinPower Turbo inline-six with 48V mild hybrid technology. Provisional figures list a maximum output of 326 kW, 580 Nm of torque, a 0-100 km/h time of 4.1 seconds and a top speed of 250 km/h. Standard equipment includes Adaptive M Suspension, Variable Sport Steering and a controlled rear differential lock, with three drive modes: Personal, M Sport and M Sport+. Chassis-specific hardware includes unique spring and damper tuning, front body struts, stiffer anti-roll bars and revised camber, while aerodynamic components include a front air deflector and a rear Gurney flap intended to improve high-speed stability.
The M350’s xDrive system uses a multi-plate clutch that can fully decouple the front axle to reduce drivetrain losses or direct torque forward as driving conditions demand. BMW says there is no fixed default torque split. In standard driving modes, the clutch is kept ready to close within approximately 100 milliseconds, while in DSC-off track driving the system introduces additional clutch clearance to reduce drag at the cost of roughly 20 additional milliseconds of response time. Torque distribution is calculated continuously by comparing driver input at the pedal and steering wheel against the rear axle’s available traction, using data from the 6D motion sensor.