There are three certainties in life: death, taxes, and that BMW‘s M department will under report its vehicles’ horsepower figures. The performance brand’s latest vehicle, the XM, is no exception.
In a new video, published by IND Distribution, which may be the first-ever independent dyno test of a BMW XM, it is revealed that the new flagship SUV is a powerful beast, indeed. While the results are less than conclusive, they are impressive all the same.
On the rollers, the XM’s twin-turbo 4.4-liter plug-in hybrid V8 is measured putting down 614.84 hp (458.49 kW/623.37 PS) and 569.14 (771.65 Nm) of torque at the wheels. IND Distribution estimates that, if you factor in a 20 percent loss for the all-wheel-drive vehicle, it is making 768 hp (573 kW/779 PS) and 712 lb-ft (965 lb-ft of torque) at the crankshaft.
Read: We Get Up Close To The 2023 BMW XM Plug-In Hybrid SUV
Now, there are always a lot of caveats to consider when looking at independent dyno tests, but this one has even more. To begin with, engines (and, therefore, dynamometers) are sensitive to a lot of factors, such as altitude, humidity, and whether Mercury is in retrograde. That means that you have to be careful when comparing dyno runs in Illinois, where this test was conducting, versus those from Germany.
IND Distribution also made an intentional effort to point out all of the issues it had conducting these tests. For one, on the run in which the highest power level was measured, there was an unexpected power spike at 6,500 rpm, which they say made them “question [the] real-world accuracy” of the test.
The team adds that it is unclear how the power unit works in dyno mode, whether the fact that the batteries were not fully charged had an impact on the tests, and whether or not adding more break-in miles to the XM would affect the results.
In subsequent runs, without the power spike at 6,500 rpm, the team estimates that crank horsepower would be closer to 715 hp (533 kW/725 PS) and 645 lb-ft (875 Nm) of torque. That’s still considerably more than the regular XM is rated for: 644 hp (480 kW/653 PS) and 590 lb-ft (800 Nm) of torque.
Whether that’s because of some strangeness withe hybrid system or some other unknown factor, it’s still an impressive reading for the SUV. However, given BMW M’s history of underrating its engines, it isn’t a surprising one.