Driving a 300-hp, 3400-pound rear-drive coupe built on a short-wheelbase chassis adds up to a great deal of driving enjoyment, especially when the engine's torque curve is absolutely flat from 1300 to 5000 rpm and the engine redlines at 7000 rpm.
The 135i's 24-valve inline-6 packs two turbochargers and makes more than 100 hp per liter, which is considered engineering magic. BMW says a manual-shift 135i will accelerate from rest to 60 mph in a mere 5.1 seconds, which is not something that most cars in this projected price category can do. Top speed is electronically limited to 130 mph (or 149 mph with the Sport Package). EPA estimates are 17 mpg city/25mpg highway with the manual transmission; and 18/25 with the automatic.
Because the BMW 135i is essentially a scaled-down 335i, its ride, steering, and handling carry the same exemplary qualities as the larger car. Its smaller front steering tires are matched to the job of pointing the car while the fatter rear tires lay the power down in wonderfully linear fashion. The car's weight is distributed 52/48 on the front and rear tires.
The 135i's brakes use massive six-piston calipers at the front and twin-piston calipers at the rear, with 13.3-inch front discs and 12.75-inch rear discs and a built-in brake drying and anti-fade feature.
We found the steering, cornering, and braking performance of the BMW 135i to be exemplary, perfectly matched to the huge acceleration power of the engine.
We haven't driven the 128i, but we expect it will also deliver a good measure of driving enjoyment. Its engine is very slightly larger (2996 cc vs. 2979 for the 135i) but breathes at atmospheric pressure without benefit of turbocharging. It does feature the same Valvetronic valvetrain management and aluminum/magnesium construction as the 135i unit. It develops 230 horsepower and 200 pound-feet of torque which, in the slightly lighter, 3250-pound 128i, should still get your attention when you put the pedal to the floor. BMW lists a 0-60 mph time of 6.1 seconds, which is quite sprightly and just a second slower than the 135i, with the same electronically limited top speed.
Fuel economy is significantly better in the 128i, with EPA ratings of 18 mpg city/28 mpg highway with the manual transmission. (Again, the automatic picks up 1 additional mpg in the city.)
The standard suspension in the 128i is softer than in the 135i, but weight distribution is a marginally better 51/49. Brakes are 11.8-inch vented discs all around, but again, that should be more than adequate for the 128i's more modest; no, make that less extravagant performance.
Electronic driving aids abound in the 1 Series, including antilock brakes with electronic brake-force distribution and cornering brake control, dynamic traction control, dynamic stability control, and a switch that can disable the DSC system for track days or generally more involving driving through the woods. That's ABS with EBD, CBC, DSC and traction control, for those who prefer acronyms.
