Apart from one being a coupe and the other a sedan, the two cars are much the same. Both will come with a twin-turbocharged 3.0-liter straight-six engine delivering 425 horsepower and 406 pound-feet of torque. That’s only a slight increase in power over the outgoing M3’s 414-horsepower naturally-aspirated 4.0-liter V-8, but it is a significant leap in torque considering the old V-8 was delivering only around 295 pound-feet.
The gains are apparent when you look at the quoted acceleration figures. With either the standard six-speed manual or optional seven-speed M-DCT dual-clutch, you’re looking at 0-60 mph times of 4.0 seconds or less for either the M3 or M4. And BMW is typically quite conservative with its acceleration figures. Top speed of either car has been electronically limited to 155 mph.
Performance in the cars is also improved significantly by weight savings. BMW says on comparably equipped models, the M3/M4 save about 176 pounds over the previous-generation M3 sedan and M3 Coupe. Most of the savings come from the use of lightweight materials for certain components, including aluminum and carbon fiber reinforced plastic.
Both cars hit showrooms later this year, as 2015 models. We’ll be driving them closer to the sales launch, at which point we’ll be able to bring you our impressions as well as the all-important pricing information.
For more from the 2014 Detroit Auto Show, head straight to our dedicated hub.