The BMW 1 Series M is nearly as well-rounded as the larger M3, but any advantages — beyond its lower price — are hard to find.
Size is perhaps the 1M's best reason for being. Over the years, criticism has grown in concert with the M3's size and weight, and the 1M is closer in size to the original M3, which was introduced to North America in 1988. As for weight, well, at 3,296 pounds, it outweighs the '88 by more than 550 pounds. That said, you're unlikely to find any modern car that's anywhere near as light as its 23-year-old forebear, and at least it's 408 pounds lighter than the M3 coupe and 77 pounds lighter than the 135i.
The M Formula
Following the M car formula, the 1M features increased power, a manual transmission, rear-wheel drive, a modified suspension, fat tires and a distinctive look — perhaps more distinctive than the other Ms. The car's track is 2.8 inches wider in front and 1.8 inches wider in rear than the regular 1 Series, so the fenders have swollen as well, resulting in an exaggerated, almost cartoony style that might appeal to some BMW fans — and turn off others. Familiar 19-inch alloy wheels are shared with the M3's optional Competition Package.
Bursts of Power
The 1M's powertrain is the car's high point, providing ample torque at low engine speeds for a satisfying launch. This twin-turbocharged 3.0-liter inline-six-cylinder produces 335 horsepower at 5,800 rpm and 332 pounds-feet of torque at 1,500 rpm. For comparison, the 335i coupe uses a single-turbo 3.0-liter I-6 with 300 hp and 300 pounds-feet. The displacement and compression ratios are the same, but the 135i's boost pressure is 8.7 psi and the 1M's starts at 11.6 psi. I say "starts" because the 1M's turbo can up the pressure to 14.5 psi for a momentary burst of torque, rated at 370 pounds-feet.
The boost works: Nail the gas pedal at practically any speed in any gear, and after waiting a half-beat you'll feel the additional tug. I'd find this annoying if the initial power were anemic, but you get respectable response even before the surge. The low-rev torque peak that extends from 1,500 rpm all the way to 4,500 rpm continues to surprise anyone who has decades of turbocharger experience. In some ways, I prefer the 1M's ready torque to the M3 V-8's gentle rise. Despite their relatively small displacement, modern turbocharged direct-injection engines deliver the character that many larger, normally aspirated V-8s no longer do. Fantastic.
BMW didn't mess with the 135i's success: It carried over the six-speed manual's gear ratios, a good match for the 1M. The only difference is a shorter final drive ratio of 3.154 in the 1M versus the 135i's 3.077. I prefer the 1M's shifter and clutch over those of the M3, whose stick is rubbery and disconnected and whose clutch pedal presents a peculiar, nonlinear resistance through its motion. The 1M's shifter isn't my favorite, but it is an improvement, and the pedal is consistent. Borrowed from the M3, the brakes — with their 14.2-inch front and 13.8-inch rear cross-drilled rotors — do a stellar job with this lighter car.