Starting this fall, the Z4 roadster will not have six explosions per revolution of its sDrive28i cam shaft, as the car will boast the new N20 2.0-liter four-cylinder engine with a twin-scroll turbocharger.
Thankfully, the Z4 sDrive35i and sDrive35is with 3.0-liter turbocharged inline-six engines will still be offered, but we find it kind of strange how the roadster has changed from the Bangle era model that was strange-looking, stiff and sonorous. Now, it just looks like every other BMW out there, sounds like a tuned hatchback and is as controversial as milk on cereal.
Getting back to the N20, we’ll tell you that in US spec it produces 240 horsepower at 5,000 rpm and 260 lb-ft of torque at just 1,250 rpm. That doesn’t sound all that impressive, considering how exclusive a BMW roadster should feel like compared to... say the Megane RS that offers 250 horsepower, but the Bavarians say we can expect fuel efficiency gain of approximately 20% over the naturally aspirated engine it replaces when combined with the 8-speed automatic transmission.
That’s good and all, but we don’t thing roadster buyers want an efficient, logical, responsible four-cylinder. We’re really going to miss the straight-six’s metallic exhaust note.
“The patented BMW VALVETRONIC system with seamlessly variable intake valve lift control dispenses with the throttle valve system typical of conventional engines. Instead, combustion air mass is controlled inside the engine, resulting in much faster response. Pumping losses are kept to a minimum, making the engine more efficient,” BMW boasts.