The BMW M340i xDrive is not a true M car, but that’s ok because the C43 isn’t a full-fat AMG model either. A new back-to-back comparison test orchestrated in Japan focused on the performance delivered by the two sports sedans in the good ol’ 0 to 62 mph (100 km/h) sprint. Although they’re direct rivals, these German luxury saloons have entirely different powertrains.

While the new C43 has lost its predecessor’s 3.0-liter V6 in favor of a 2.0-liter four-cylinder engine, the M340i soldiers on with its 3.0-liter inline-six. With the Life Cycle Impulse introduced last year, the M Performance version of the G20 3 Series Sedan gained a mild-hybrid setup that provides a temporary boost in output of 11 horsepower but the ICE continues to have 374 hp and 500 Nm (369 lb-ft).

Speaking of partial electrification, the four-pot that goes into the latest AMG C43 also utilizes 48V tech and it actually outpunches BMW’s inline-six. Well, at least on paper. Mercedes says the small 2.0-liter unit is good for 408 hp and an identical 500 Nm (369 lb-ft). The mild-hybrid system offers a brief jump in output of 14 hp. How do these numbers translate to real life? The folks over at StartYourEnginesX decided to test them one after the other.

The Mercedes was the first to go and needed 5.58 seconds to hit 62 mph (100 km/h) from a standstill in Comfort mode. Switching to Sport+ unlocked the AMG C43’s full potential to lower the sprint time to 4.8 seconds. However, that was still 0.2 seconds slower than what the technical specifications sheet says.

How did the BMW fare? The M340i xDrive took 4.9 seconds in Comfort mode and 4.6 seconds in Sport+. While it did comfortably beat the Mercedes, it too wasn’t able to match the official time. The Munich-based automaker quotes a 4.4-second sprint, so just like the AMG, the M340i was two-tenths of a second slower than the manufacturer’s claim.

It remains to be seen for how long BMW will sell the M Lite 3 Series with an inline-six given increasingly stringent emissions regulations. In the meantime, you can not only get an M340i but also an M340d with a torquetastic six-cylinder diesel for which AMG doesn’t have a rival.

Source: StartYourEngines X / YouTube