BMW has just launched its all-new F90 M5 flagship, but this isn’t the only high performance version of the G30 5 Series on offer. Sitting just below the M5 is the M550i xDrive that was introduced together with the rest of the G30 range last year.
At a glance, the M5 and M550i xDrive seemingly share a similar mechanical template – 4.4-litre twin-turbocharged V8 driving all four wheels via ZF’s 8HP 8-speed automatic transmission.
The M550i is part of BMW’s M Performance line up, and consequently sits lower in the hierarchy from the full-blooded M model. Nevertheless, despite being nearly 100 hp down on power from the F10 M5, the M550i manages to sprint from 0 to 100 km/h faster by 0.3 seconds.
We can perhaps attribute this discrepancy to the M550i’s superior all-wheel traction and reduced weight over the F10 M5. The M550i is also marginally more efficient with fuel, using a whole litre of fuel less per 100km on the combined cycle.
The F90 M5, on the other hand, receives a substantial boost in power and torque over its predecessor and translates that advantage to a 0.9-second improvement of its century sprint time.
Here are the facts and figures:
Externally, whilst the M550i shares common body parts with regular 5 Series M Sport variants, the M5 gets its unique set of body panels, notably at the front, where a creased aluminium bonnet takes the place of the regular steel item.
The M5’s front fenders, also made from aluminium, are not only flared to accommodate a wider axle track, but also sees the lower air curtain vent from the regular 5 Series erased and replaced with the signature M gills higher up.
The M5’s front bumpers are also carved with larger air intakes, although the M550i strikes back with a no less expressive matt silver trim piece that accentuates its own corner air vent. The M5 also gets its own carbon fibre roof for further weight reduction.
At the rear, both the M5 and M550i get aggressively-shaped bumper diffusers and quad tail pipes. The M550i has more darkened areas, but the M5 gets a more expressive take with sharper and more clearly defined creases.
Inside, both cabins share a common architecture. The three-spoke M steering wheel look largely identical save for the bright red M1 and M2 buttons found in the M5. The M5 also get more technical-looking fonts on its instrument cluster as well as a more elaborate electronic shifter to operate its 8-speed auto.
On paper, little seems to separate these two V8-powered high-performance flagships of the BMW 5 Series range. Given its technical similarities with the F90 M5, the M550i already seems like progression over the previous-gen F10 M5 - a faster 0-100 km/h time sees to that.
It is interesting how BMW see these two cars would co-exist. Our speculation is that whilst the M5 represent the absolute limit of performance possible with today's engineering, the M550i offers more than one would typically require in a more understated and friendlier to use day-to-day. In fact, the M550i's product proposition appears to be edging rather close to the Alpina B5's territory whilst the M5 focuses its guns on the 600hp monster lurking at the Mercedes-AMG corner.