The first BMW XM Label—the company’s most powerful production vehicle to date with 738-horsepower and 738 lb-ft of torque on tap—set a new record for hybrid electric SUVs at Pikes Peak in Colorado Springs on 21 September, during an officially certified course run.
Following a previous attempt for the race day record in June during the 101st running of the Broadmoor Pikes Peak International Hill Climb, BMW driver Matt Mullins returned to take on the course last month aboard the range-topping BMW XM Label with support from Rhys Millen Racing. Reaching the summit in 10:48:60, Mullins outpaced the previous race day record by nearly a second and a half.
With more than 150 turns at staggering elevations, the uniquely challenging Pikes Peak run starts at 9,390 feet above sea level and finishes at the 14,115-foot summit of America’s Mountain. Pikes Peak’s reputation for difficulty is matched only by its legendary status in the history of motorsport, which dates back more than a century.
Under the hood, the BMW XM Label features a 738-horsepower hybrid electric drivetrain derived from BMW’s newest endurance racing car, the BMW M Hybrid The maximum system output of 738 hp represents a 94-hp increase over the standard BMW XM. Overall system torque is up by 148 lb-ft and now peaks at 738 lb-ft. Power is sent to the road by the M xDrive all-wheel-drive system.
The latest generation of the V8 delivers extremely rapid power delivery, increased efficiency, and minimized emissions. As well as a cross-bank exhaust manifold, it also features a reinforced crankshaft drive, turbocharging with an electrically controlled blow-off valve, upgraded oil supply, and optimized oil separation.
In the BMW XM Label, the 4.4 liter V8 alone produces 577 hp at 5,600 rpm. Peak torque is 553 lb-ft and is available from 1,800 to 5,400 rpm. Like the V8 engine, the electric motor of the M HYBRID system also employs innovative technology to deliver a noticeable increase in power.
The permanently excited synchronous motor is integrated into the 8-speed M Steptronic transmission together with its power electronics, and helps to provide precise throttle response and nearly instantaneous power delivery.
The electric motor contributes up to 194 hp to the maximum system output of the BMW XM Label Red along with 206 lb-ft of torque. A pre-gearing stage patented by BMW is used to increase the torque produced by the motor to an effective maximum of 332 lb-ft at the transmission input for the motor. In this way, the compact motor is able to provide the sort of torque boost that could normally only be achieved using a far larger and heavier unit.
The improved build-up of power resulting from the pre-gearing stage between the electric motor’s rotor and the transmission’s input shaft can be clearly felt, both when accelerating off the line and when putting in a quick burst of speed. Combined with the optimized power delivery of the V8 engine and its high-revving character, this produces astonishing acceleration. The BMW XM Label needs just an estimated 3.7 seconds to sprint from 0 to 60 mph. Top speed is electronically limited to 155 mph, or 175 mph when the optional M Driver’s Package is specified.
The electric motor draws its energy from a high-voltage lithium-ion battery integrated into the underbody. The 19.2 kWh net battery provides a constant flow of power across a wide temperature range and under the heavy loads encountered in high-performance driving. Together with the electric motor’s excellent efficiency and the system of intelligent energy management, this enables an estimated all-electric range of about 30 miles. The BMW XM Label can achieve 87 mph in electric mode.
The Combined Charging Unit of the M HYBRID system enables AC charging at up to 7.4 kW. This means the high-voltage battery can be replenished from zero to 100% charge in 3.25 hours. Predictive heat management reduces charging times by preconditioning the HV battery.