Autocar says a move to the CLAR architecture underneath BMW's larger sedans and a few SUVs brings immediate weight dividends. So even though the 2020 M3 should grow by about six inches in length, it will come in under the 3,494 pounds of the current CS. The additional stiffness in the platform, and a slight elongation in wheelbase by 0.79 in, could also allow engineers to program softer spring rates in Comfort mode. That would give occupants a more luxurious ride when the driver isn't going hammer and tongs.
The UK mag pegs the horsepower bump at 465 hp, an 11-hp rise over the M3 CS. BMW Blog figures the range will come in somewhere between 450 hp — which would be less than the M3 CS — and 500 hp. The 3.0-liter straight-six will undoubtedly get major upgrades, but Autocar posits the water injection system from the M4 GTS might make a move to the M3's engine bay. However, packaging the system and its extra water tank might add more complexity than desired, and BMW's already said it doesn't want to complicate the sedan. That's why hybrid assistance has been ruled out.
There are competing ideas about the transmission and rear-wheel steering, too. Autocar says a six-speed manual will be the de facto gearbox, the eight-speed ZF automatic from the M5 serving as the option. BMW Blog believes the M division might stick with the seven-speed dual-clutch in spite of its expense compared to the ZF transmission. The M5 needed the eight-speed to handle 553 pound-feet of torque, but the M3 won't have as much torque as the M5.
Autocar believes BMW will install its Integral Rear Steer into the 2020 M3. That would erase some of the weight advantage of the CLAR architecture, yet rumors of a more hardcore rear-steering system could make the new M3 the benchmark for turn-in, agility, and high-speed stability. If the setup does make the cut, the M3 would be the only sports sedan in the segment with that option.
Evolutionary looks honed by the wind tunnel will wrap the package. Although a debut's scheduled from sometime early next year, we shouldn't expect to see the sedan in dealers until the end of next year. As has happened at Volkswagen, BMW will shut down M3 production for about a year to deal with Europe's Wordldwide Harmonized Light Duty Vehicles Test Procedure.