Guide: BMW E63 M6 Coupe & E64 M6 Convertible
Background
Even though the elegant E24 6-series had been the driver’s choice when it came to executive class Coupes from the mid 1970s to the late 1980s, BMW chose not to offer a direct replacement when production was discontinued in 1989.
Instead, the Bavarian firm decided to move their flagship pillar-less Coupe even further upmarket in the shape of the E31 8-series which was initially offered with a five-litre V12 motor from 1990, after which a V8 followed in 1992.
Unfortunately, the move into substantially more expensive territory backfired as reaction to the E31 was lukewarm at best. Furthermore, by the time production was in full flow, a long, hard recession had begun to take hold which slashed demand for high end motor cars.
Between 1990 and 1999, BMW managed to sell just over 30,000 8-series in all its different variations compared to more than 86,000 6-series between 1976 and 1989.
Another consequence of the 8-series poor reception was that a high performance M8 never made it beyond the prototype stage as it was thought there was simply not sufficient demand to warrant the development cost. This left the much smaller M3 as the only Motorsport-tuned Coupe in BMW’s range for well over a decade.
The 6-series finally made a long overdue return when the E63 variant was unveiled at the Frankfurt Motor Show in September 2003. Production began that same month for the 2004 model year, at which point BMW offered their new Coupe with either a 254bhp three-litre inline six (the 630 Ci) or a 328bhp 4.4-litre V8 (the 645 Ci).
A Convertible version (the E64) was subsequently displayed at the Detroit Motor Show in January 2004 and went into production shortly afterwards. It meant the firm’s customers were finally able to buy an open topped BMW-badged alternative to the big long-running cabriolets from Mercedes-Benz and Jaguar.
The next iteration of the E63 / E64 to arrive was arguably the most highly anticipated of all: BMW’s Motorsport-tuned E63 M6 Coupe. Exhibited at the Geneva Motor Show in March 2005, it marked a return for the M6 moniker after a 16 year absence.
18 months later, an E64-based M6 Cabriolet broke cover at the Paris Motor Show which gave BMW another hitherto unseen offering for its product line-up.
Both M6s were built on the regular 6-series production line at Dingolfing 100km north west of Munich.
Chassis
The E63 was based upon a shortened version of the E60 M5’s galvanised steel monocoque bodyshell. At 2781mm the wheelbase was reduced by 108mm.
Similarly, both cars shared an identical all-aluminium suspension set-up with MacPherson struts up front and a multi-link arrangement at the back. Compared to other 6-series variants, spring and anti-roll bar rates along with the stiffness of the bushes were unique to the M6.
Much of the remaining ancillary equipment was also shared between the M5 and M6 to include the state-of-art software employed along with the brake system.
Electronic Damping Control constantly adapted the stiffness of the shock absorbers to the road conditions. In addition, the driver could manually select one of three shock settings (Comfort, Normal and Sport) either via the MDrive button on the steering wheel or a button located alongside the SMG lever.
Dynamic Stability Control worked in conjunction with the M Variable Differential Lock fitted as standard. Like earlier iterations of DSC, engine power was automatically adjusted along with individual wheel braking to improve stability.
In addition, this latest evolution of DSC came with Brake Standby (which automatically moved the pad to the disc in preparation for had braking during sudden throttle lift), Brake Drying (which automatically moved the pad against the disc in the event the rain sensor detected any pad moisture) and Start-Off Assistant (which held the brakes for one second after the driver's foot was removed from the brake pedal in uphill conditions).
If required, the DSC thresholds could be adjusted via M Dynamic Mode or switched off entirely.
An MDrive function allowed the car’s settings to be further customised with regard to the SMG Drivelogic gearbox software (eleven modes), engine power (two modes), throttle response (three modes) and the Servotronic variable assistance power steering (two modes). MDrive could also be used to adjust the trio of alternative modes for the aforementioned EDC and DSC systems.
Ventilated brake discs were cross-drilled for the M5 / M6 and substantially bigger than regular 5 / 6-series variants. The fronts measured 374mm across with dual piston calipers and the rears were 370mm with single-piston calipers.
ABS was fitted as standard.
Instead of the Radial Spoke 166M cast alloy wheels fitted to the M5 (available as an option), the M6 came with BMW’s forged and polished M Double Spoke 167M type rim shod with Pirelli P Zero Corsa tyres. Wheel size was an unchanged 8.5 x 19-inches at the front and 9.5 x 19-inches at the rear.
Like all 5 and 6-series variants of the time, a 70-litre fuel tank was installed under the rear seat.
Engine / Gearbox
In the engine bay was the M5’s F1-inspired BMW Motorsport five-litre normally aspirated 90° V10 which was hooked up to an identical seven-speed SMG III sequential gearbox.
These Type S85 B50 engines featured an all-alloy construction with dual overhead camshafts, four valves per cylinder, a semi-dry-sump lubrication system, a forged five-bearing crankshaft and high-pressure double VANOS variable valve timing.
To reduce mass, BMW Motorsport added flow-optimised 5mm shaft valves, spherical valve tappets with hydraulic valve play compensation, single valve springs, lightweight valves and hollow camshafts. To further increase the engine’s responsiveness, simultaneously actuated and electronically-controlled individual throttle assemblies were added for each cylinder.
Displacement was 4999cc thanks to a bore and stroke of 92mm and 75.2mm respectively.
The compression ratio was set at 12.0:1.
A state-of-the-art MSS65 DME engine management system was capable of 200 million operations per second.
Peak output was 500bhp at 7750rpm and 384lb-ft at 6100rpm.
Driver’s could select from one of three alternative drive modes via a Power button mounted alongside the SMG lever.
The default P400 mode limited the engine to 400bhp and adopted the standard throttle response algorithm. P500 mode freed up the full 500bhp and also quickened the throttle response. P500 Sport mode (accessible via the MDrive button on the steering wheel) gave an even sharper throttle response.
Transmission was via BMW’s third generation Sequential M Gearbox (SMG III) which had been the first seven-speed sequential put into production by any manufacturer.
As per previous iterations of the SMG transmission, SMG III allowed the driver to shift gears via F1-style paddles mounted behind the steering wheel or a centrally located lever. There was also a fully automatic mode. Additionally, the new system offered a choice of eleven shift maps (six manual and five automatic). Shift times were said to be 20% faster than before and there was also a launch control facility.
The mechanical Variable M Differential Lock was effectively an updated limited-slip diff. It pressurised a viscous silicon fluid when there was a difference in rotational speed between the rear wheel and then activated a multi-disc clutch that directed more power to the wheel with the greatest traction.
Hollow halfshafts unique to the M5 / M6 were fitted to save a little weight.
Bodywork
Like the concurrent 5 and 7-series models, the latest generation 6-series adopted BMW’s controversial flame surface approach to styling that mixed concave and convex shapes to create sharp edges.
To save weight, the regular 6-series already used aluminium for the doors and hood, carbon-reinforced plastic (CFRP) for the trunk and front fenders and glassfibre-reinforced plastic for the bumper assemblies.
For the M6, BMW added an exposed CFRP roof panel that weighed 7kg less than the normal steel panel and helped lower the car’s centre of gravity.
New bumpers, skirts and exterior mirrors were also installed.
The front bumper featured enlarged, more aggressively styled openings for the brakes and intake silencer. No fog lights were fitted and the chin spoiler was optimised to create a little extra downforce.
A similar approach was taken at the back of the car where the new rear bumper was redesigned to incorporate an integrated diffuser and four 80mm exhaust outlets that were partially shrouded by aerodynamically profiled flaps.
The bumpers themselves were mounted on new deformable glassfibre-reinforced plastic carriers to further reduce weight.
Down each flank were sporty new skirts with ram air lips ahead of the rear wheels and smaller, more aerodynamic mirrors.
An M6 badge was added down to each front fender and the trunk lid.
Interior
Inside, the M6 adopted the instrumentation and switchgear from the contemporary M5 while the dash and central control panel were imported from the regular 6-series. Both the 5 and 6-series featured a slightly more restrained interpretation of the ultra-modern E65 7-series design approach with all three models incorporating an iDrive infotainment system with dash-mounted 6.5-inch LCD screen through which the majority of the car’s functions were accessed via a transmission tunnel-mounted rotary switch.
Compared to other 6-series, the M6 was supplied with an array of special equipment to reflect its sportier nature.
There was a small diameter three-spoke steering wheel with M tricolour stitching, behind which was custom instrumentation. This comprised a large analogue 330kmh / 200mph speedometer with integrated fuel read out and matching 9000rpm M-branded rev counter with combined oil temperature display.
Located around the M-branded SMG shifter were buttons for the Power mode, DSC and EDC.
Electric M Sport seats (an option on the rest of the 6-series range) were fitted as standard along with Extended Merino leather. In standard trim, leather was used to cover the seats, door panel inserts and all the armrests. The headliner was trimmed in Anthracite cloth.
Other special features included M6-branded illuminated sill plates and an M Design driver's footrest.
Walnut Madeira wood trim was installed as standard.
The long list of standard equipment included a full complement of airbags, satellite navigation, electric heated front seats, remote central locking, automatic air-conditioning, a DAB audio system with six disc CD shuttle, rain-sensing headlights, tyre pressure monitoring, parking sensors with pictogram display, cruise control, remote trunk and fuel filler releases and adaptive bi-Xenon headlights.
Options
Olive Ash wood interior trim was offered on the M6 as a no-cost option while exposed Black Carbonfibre could be specified at additional cost.
Customers could also request a premium sound system and a 6 x 3-inch head-up display that projected details of road speed, engine speed and gear selection onto the windscreen.
The Complete Merino Leather option added hide to the dash, upper and lower door panels and the centre console.
Other upgrades included alcantara headliner and the Style 166M Radial alloy wheels from the M5.
Weight / Performance
The E63 M6 Coupe weighed in at 1785kg which was 45kg less than the E60 M5 Saloon upon which it was based.
The 0-62mph time was a tenth quicker (4.6 seconds) and top speed was once again limited to 155mph.
2006 Model Year
Production of the 2006 model year M6 began in September 2005 with the most significant change having been the switch from a conventional ignition key to a remote key with stop-start button.
2007 Model Year & E64 M6 Convertible
Production of the 2007 model year variant began in September 2006 at which point BMW introduced the E64 M6 Convertible.
Based around a suitably reinforced bodyshell, the M6 Convertible was among the fastest full four-seat cabriolets on offer. Top speed was limited to 155mph and 0-62mph took 4.8 seconds (up from 4.6). It weighed 2005kg which represented a 220kg increase compared to the Coupe.
Specification changes for the 2007 model year included an improved satellite-navigation system and an audio system now with auxiliary input added.
A new option included an HD Radio which could be ordered in combination with the Logic7 or Premium Sound system.
Neiman Marcus Limited Edition
In October 2006, luxury US retailer Neiman Marcus announced a limited run of 50 specially configured M6 Convertibles as part of its famous Christmas catalogue.
Each car was painted Ruby Black Metallic with Gold Brown complete Merino leather upholstery, both of which were BMW Individual options. Previously unseen features were Piano Black interior trim and a hood with two contoured creases dubbed precision lines – this handsome feature was later adopted for the optional Competition Package (available on the M6 Coupe for the 2009 model year) and the M6 Coupe Competition Edition (available for the final year of production, 2010).
Other equipment fitted to the Neiman Marcus M6 Convertible included the Head-up Display, Comfort Access keyless entry with multi-fuction remote control and an HD Satellite radio. Purchasers also received a trip to the BMW headquarters in Munich.
All 50 cars were sold within the first hour of availability. They were subsequently produced between January and February of 2007.
Mid 2007 Model Year Production Changes
In March 2007 BMW added soft-close doors and an improved BMW Individual Premium audio system with additional speakers to the options list.
There was also a new option specific to the North American M6: a six-speed manual ZF Type G gearbox but cars equipped as such were not available with the Head-up Display option.
2008 Model Year
The 2008 model year M6 (production of which began in September 2007) ushered in a revised head and tail light design that now featured LED indicators. There was also a subtly revised trunk lid, an updated iDrive display (with programmable memory buttons and a new controller), active front head rests and a cargo net in the trunk.
Six-speed manual versions of the M6 now came with a disable feature for the Dynamic Stability Control.
New options included a heated steering wheel, an iPod / USB adapter and automatic high beam light assist. Sun Reflective Technology was added to M6 Convertibles equipped with Merino leather upholstery.
Russia Limited Edition
Between February and April of 2008, BMW produced a batch of 25 Russia Limited Edition variants in a mix of Coupe and Convertible body styles.
The specification was identical to the aforementioned Neiman Marcus Convertible.
Of the 25 built, 21 were E63 Coupes and the remaining four were E64 Convertibles.
2009 Model Year
For the 2009 model year (production of which began in September 2008), BMW installed an updated iDrive controller with fixed buttons.
There was also new a new Competition Package offered exclusively on the E63 M6 Coupe.
M6 Coupe Competition Package
The Competition Package focused on improved handling and to that end included a set of shorter springs that lowered the ride height, stiffer shock absorbers, thicker anti-roll bars, half-inch wider M Double Spoke 167M forged alloy wheels and R-compound Pirelli P Zero Corsa tyres.
The other equipment thrown in as part of the Competition Package was a twin contoured precision line hood, an uprated version of the Variable M Differential Lock and revised Dynamic Stability Control software.
Mid 2009 Model Year Production Changes
In March 2009, BMW brought in an updated iDrive system (iDrive 2.0) with an 80 GB hard drive-based navigation system and a larger screen with improved graphics.
For some markets there was also a BMW EfficientDynamics brake energy regeneration system and BMW ConnectedDrive internet capability.
M6 Coupe Competition Edition
At the Frankfurt Motor Show in September 2009, BMW unveiled an M6 Coupe dubbed the Competition Edition which featured all the upgrades included with the aforementioned Competition Package plus some other bits and pieces too.
Each car was painted Frozen Grey and offered with one of two complete Merino leather colour schemes: mono-tone Black or two-tone Black and Silverstone, both of which were BMW Individual options. This was complemented by Light Grey contrast stitching and Anthracite floor mats with Silverstone trim.
Also fitted were unique door sill plates complete with M6 Competition script and a roof-mounted numbered plaque above the rear view mirror.
BMW planned to build 100 examples of the Competition Edition, but only 63 were ultimately produced (54 left-hand drive Euro market versions, eight right-hand drive Euro market versions and one left-hand drive North American version for Canada).
In addition, BMW Canada offered its own batch of ten M6 Coupe Competition Editions that did not come with the Frozen Grey over Black or Black and Silvertsone colour scheme. Uniquely, they were supplied with a Competition Edition badge on the trunk lid and a black wood and carbonfibre key box.
End of Production
E63 M6 Coupe production ran from March 2005 until July 2010, by which time 9087 had been completed.
E64 M6 Convertible production ran from September 2006 to July 2010, by which time 5065 had been completed.
Total E63 / E64 M6 production was therefore 14,152 units split as follows:
LHD Euro market M6 Coupe (03/2005 to 07/2010) 3880 built
LHD North American market M6 Coupe (03/2005 to 07/2010) 3887 built (323 with six-speed manual)
RHD Euro market M6 Coupe (09/2005 to 06/2010) 1320 built
LHD Euro market M6 Convertible (09/2006 to 07/2010) 1133 built
LHD North American market M6 Convertible (09/2006 to 07/2010) 3512 built (379 with six-speed manual)
RHD Euro market M6 Convertible (09/2006 to 06/2010) 420 built
A replacement based on the F13 Coupe was launched at the 2012 Geneva Motor Show and was also produced in F12 Convertible and F06 Gran Coupe trim.
Text copyright: Supercar Nostalgia
Photo copyright: BMW - https://www.bmw.com
