According to the fellas at Car and Driver , the BMW 135i coupe is a winner when it comes to performance and straight line speed. In their tests, the new BMW 135i managed to get to 6 0mph in exactly 4.7 seconds, which is about 0.1 sec faster than the bigger brother – the BMW 335i. Being built on a smaller chassis definitely helps a lot. The 135i is 8.9 inches shorter than a 335i coupe, with 4.0 inches taken out of the wheelbase, and is also 1.4 inches narrower. The smaller size is reflected in the weight savings as well, the 335i weighs 3557 lbs while the slimmer 135i stops at 3420 lbs.
But here are some fragments from their review:
At 4.7 Seconds to 60, Smaller Is Certainly Quicker
In overall length, the 135i coupe (the 1-series is only available in the U.S. as a two-door coupe) is 8.9 inches shorter than a 335i coupe, with 4.0 inches taken out of the wheelbase, and it’s also 1.4 inches narrower. These reductions amount to a weight saving of 137 pounds; our 135i weighed 3420 pounds versus 3557 for a 335i coupe.
Fortunately, there is no reduction in engine size or output. The 135i gets the same 300-hp twin-turbocharged inline six-cylinder engine as the 335i. We clocked a 0-to-60 time of 4.9 seconds for the heavier 335i; the 135i did it in a blistering 4.7, with a 13.3-second quarter-mile at 106 mph. The 135i is seriously quick, but best of all, the quickness comes easily, as the turbocharged engine has enough torque and horsepower to waft the 135i into triple-digit speeds without any drama. Slightly more engine noise and exhaust hum enter the 135i cabin than in the 335i, but the sounds are good enough to forgo turning on the radio.
Full review continued here