Photo: carwow on YouTube / modified
The British guys at carwow are back with another interesting drag racing video, where one of the most controversial BMW models takes on one of the most desirable Bimmers of all time. Modified by German tuner Manhart, both the XM Label and the M4 CSL in the featured clip are more nasty and powerful than the stock ones.
Let’s start with the MHXM 800, which packs a twin-turbo V8 plug-in hybrid powertrain that makes 800 horsepower instead of the factory 748. Converted to horsepower, that’s 789 and 738 combined. Peak torque, meanwhile, is rated at 1,100 or 1,000 newton meters (811 or 738 pound-feet).
The XM Label’s S68 engine is mated to a rather ubiquitous eight-speed automatic transmission from ZF, which is also used by the M4 CSL inline-six. As you may have guessed by now, the XM Label also boasts M xDrive all-wheel drive rather than the rear-wheel drive of the slimmer coupe. Originally advertised with 550 hp and 650 Nm to its name, the M4 CSL has been improved to 702 hp and 880 Nm of torque.
That’s 692 horsepower and 649 pound-feet from a 3.0-liter displacement, and that’s without any hybrid assistance whatsoever. Unfortunately, the BMW M2 through M4 lines have yet to receive a 48-volt starter-generator or plug-in hybrid system for the S58 engine. The elephant in the room, however, is the curb weight.
If the limited-edition M4 CSL weighs 1,625 kilograms (3,583 lb) according to European specifications, are you willing to bet that the XM Label weighs 2.2 or 2.3 tonnes? In fact, the XM’s more racy sibling is quoted by the Munich automaker at a whopping 2,720 kilograms (5,997 lb).
Photo: carwow on YouTube
Considering the 2,500-pound difference, it’s easy to believe the M4 CSL will have the upper hand in the quarter-mile. But alas, the rear-wheel-drive contender has some trouble getting all that power to the rear wheels. With Sam Maher-Loughnan at the wheel, the cooler of the two Bimmers couldn’t better 11.6 seconds than Mat Watson’s 11.5 seconds in the Manhart-tuned XM Label.
In addition to a remapped electronic control unitThe M4 CSL also gets a carbon fiber intake system, less restrictive downpipes, and high-flow catalytic converters for good measure. While Sam struggles to put the power down even from a roll, the MH4 GTR II makes the all-wheel-drive sports utility vehicle feel sluggish from a roll start.
In both normal and sportier settings, the Bavarian coupe doesn't sweat a roll at the half-mile mark. On the other hand, Sam did experience a drop in thrust in fifth or sixth gear. Finally, the emergency braking test from 160 kilometres per hour (nearly 100 miles per hour) saw the M4 CSL stop slightly worse than the Off-road.
Whether it's the brakes, tires, or Sam's reaction time, it doesn't really matter because a puddle of washer fluid formed under the XM label after the emergency stop test. Upon further investigation, the washer fluid reservoir cap does not secure as expected, allowing fluid to spill out of the reservoir under heavy braking.
