BMW 6 series

Which BMW 6 Series Version Should You Buy?

The BMW 6 Series choice depends on whether you prioritize performance, fuel economy, body style, or mechanical simplicity. The data covers seven catalogue generation entries spanning October 1975 onward, including Coupe, Cabrio, Sedan, and Liftback bodies. For the quickest recorded acceleration, choose the restyled third-generation Cabrio’s 650i 4.4 AT xDrive at 4.5 seconds from 0–100 km/h.

The BMW 6 Series choice depends on whether you prioritize performance, fuel economy, body style, or mechanical simplicity. The data covers seven catalogue generation entries spanning October 1975 onward, including Coupe, Cabrio, Sedan, and Liftback bodies. For the quickest recorded acceleration, choose the restyled third-generation Cabrio’s 650i 4.4 AT xDrive at 4.5 seconds from 0–100 km/h. For the lowest measured combined consumption, the fourth-generation restyling’s 620d MHEV records 4.4 L/100 km. Buyers seeking a middle ground should compare the 640i and 640d families: they combine strong acceleration with lower consumption than the 650i V-shaped eight-cylinder versions.

BMW 6 Series generations: what changed?

The first generation is listed as a Coupe from October 1975 through August 2003, with 24 versions. Its sampled engines are naturally aspirated Gasoline inline six-cylinder units, ranging from 2788 cc in 628 CSi 2.8 MT and 628 CSi 2.8 AT to 3430 cc in the 635 CSi 3.4 variants. Output among the shown versions runs from 184 hp to 200 hp. Manual models use 5 gears, Automatic models use 4, and every listed version is RWD.

The second generation is listed as a Cabrio from September 2003 through January 2008, with 12 versions. It raises the performance ceiling with 645Ci 4.4 and 650Ci 4.8 variants: the 4398 cc 645Ci produces 333 hp, while the 4799 cc 650Ci produces 367 hp. All shown engines remain naturally aspirated Gasoline units, all versions are RWD, and the transmissions are 6-speed Manual or 6-speed Automatic.

The restyled second generation is another Cabrio, running from September 2007 through July 2010, with 15 versions. It adds the Diesel 635Cd 3.0 AT and 635Cd 3.0 MT, each producing 286 hp and 580 Nm from 2993 cc. Its transmission range expands to 6-speed Manual, 6-speed Automatic, and 7-speed Robotic. The Gasoline choices include naturally aspirated inline-six and V-shaped eight-cylinder engines.

The third generation is listed as a Sedan from June 2011 through February 2015, with 22 versions. Turbo becomes standard across the shown 640i, 640d, and 650i choices, while every listed transmission is an 8-speed Automatic. RWD and AWD are both available. Outputs span 313–450 hp, and recorded 0–100 km/h times range from 4.5 to 5.5 seconds.

The restyled third generation is a Cabrio from February 2015 through April 2017, with 18 versions. It retains turbocharged 640i, 640d, and 650i powertrains, 8-speed Automatic transmissions, and the choice of RWD or AWD. The shown versions offer 313–450 hp and 450–650 Nm. Because some version records differ by body specification, identical names must be compared with their power, weight, clearance, and consumption figures together.

The fourth generation is a Liftback from May 2017 through April 2020, with 10 versions. It broadens the range downward with 620d 2.0 AT and 620d 2.0 AT xDrive while retaining 630i, 630d, 640i, and 640d versions. Every shown engine is Turbo and every transmission is an 8-speed Automatic. Power spans 190–340 hp, with RWD and AWD offered.

The restyled fourth generation is a Liftback from May 2020 onward, with seven versions. Every name includes MHEV, and all versions use an 8-speed Automatic. The range comprises 620d MHEV, 630i MHEV, 630d MHEV, 630d MHEV xDrive, 640i MHEV, 640i MHEV xDrive, and 640d MHEV xDrive. Output runs from 190 hp to 340 hp, while measured combined consumption ranges from 4.4 to 7.2 L/100 km.

BMW 6 Series engine specs and versions

Repeated names are separated below by generation and, where necessary, output.

BMW 6 Series performance and fuel economy

The performance choice among the older naturally aspirated cars is the second-generation 650Ci 4.8. The 367 hp 650Ci 4.8 AT records 0–100 km/h in 5.4 seconds and 11.9 L/100 km combined, while the earlier 367 hp record of the same name takes 5.7 seconds and uses 12.9 L/100 km. The 650Ci 4.8 MT likewise appears with 5.4-, 5.7-, and 5.1-second acceleration figures depending on the listed record; combined consumption is respectively 11.9, 12.9, and 11.9 L/100 km. The 645Ci 4.4 DSG and 650Ci 4.8 DSG have no measured 0–100 km/h or consumption figures.

In the third generation, the 650i 4.4 AT xDrive is quickest at 4.5 seconds, followed by the RWD 650i 4.4 AT at 4.6 seconds. Their combined consumption is 9.3 and 8.6 L/100 km respectively, so AWD gains 0.1 second but uses 0.7 L/100 km more in these records. The 640d 3.0 AT xDrive takes 5.3–5.4 seconds and records 5.8–5.9 L/100 km combined, while the RWD 640d 3.0 AT takes 5.4–5.5 seconds and records 5.5–5.6 L/100 km.

The fourth-generation 640i 3.0 AT xDrive accelerates in 5.3 seconds, compared with 5.4 seconds for 640i 3.0 AT. Combined consumption rises from 7.0 to 8.5 L/100 km with AWD. The 630d 3.0 AT xDrive reaches 0–100 km/h in 6.0 seconds, while the 265 hp RWD 630d 3.0 AT takes 6.1 seconds; their combined figures are 5.9 and 4.9 L/100 km. The 620d 2.0 AT records 7.9 seconds and 4.9 L/100 km, whereas 620d 2.0 AT xDrive records 8.0 seconds and 5.4 L/100 km.

Among the restyled fourth-generation cars, 640i MHEV is quickest at 5.2 seconds and uses 6.8 L/100 km combined. The 640i MHEV xDrive takes 5.4 seconds and uses 7.2 L/100 km. The 640d MHEV xDrive takes 5.3 seconds while returning 5.4 L/100 km. The economy leader, 620d MHEV, records 7.9 seconds, a 220 km/h top speed, and 4.4 L/100 km combined. Every other version in this restyled range has a recorded 250 km/h top speed.

BMW 6 Series weight, clearance, tank, and wheel specs

Weight matters because the same output can produce different performance. The second-generation 645Ci 4.4 MT has 333 hp and a 1615 kg kerb weight, or about 4.85 kg per hp. The 367 hp 650Ci 4.8 MT at 1715 kg improves that ratio to about 4.67 kg per hp. Both use a 70-liter tank and have 140 mm ground clearance.

The third-generation 450 hp 650i 4.4 AT has a 1865 kg kerb weight, about 4.14 kg per hp, while a listed 450 hp 650i 4.4 AT xDrive weighs 1940 kg, about 4.31 kg per hp. The Cabrio records include 1930 kg for 650i 4.4 AT and 1980 kg for 650i 4.4 AT xDrive. Their tanks hold 70 liters, with clearance listed at 123 or 126 mm depending on the record.

The fourth-generation Liftback ranges from 1720 kg for the 258 hp 630i 2.0 AT to 1955 kg for several Diesel AWD versions. Its tank holds 68 liters and clearance is generally 138 mm, although 620d 2.0 AT xDrive is listed at 145 mm. Its rear suspension is Independent, pneumatic, unlike the Independent, spring rear setup shown elsewhere.

After restyling, kerb weight ranges from 1785 kg for 630i MHEV to 2010 kg for 640d MHEV xDrive. Gasoline versions and 620d MHEV use a 68-liter tank; 630d and 640d versions use 66 liters. Ground clearance is 138 mm throughout. Gross weight spans 2450–2685 kg.

Recorded wheel sizes are limited to selected third-generation cars: 225/55 R17 and 245/45 R18 appear on several AWD versions; one 640i 3.0 AT also lists 225/55 R17, 245/40 R19, and 275/35 R19. For every version without wheel data, wheel size is not measured. Overall length, width, and height are also not measured in the supplied data.

Which BMW 6 Series version should you choose?

Choose 620d MHEV when measured economy is the priority. Its 4.4 L/100 km combined figure is 2.4 L/100 km lower than 640i MHEV’s 6.8, although the Gasoline car cuts the 0–100 km/h time from 7.9 to 5.2 seconds and adds 143 hp.

Choose 630d MHEV for the strongest balance of RWD performance and Diesel economy. It produces 286 hp and 650 Nm, reaches 100 km/h in 6.1 seconds, and records 4.9 L/100 km combined. The 630d MHEV xDrive has identical output, reaches 100 km/h 0.2 seconds sooner, and uses 0.2 L/100 km more while adding 60 kg of kerb weight.

Choose 640d MHEV xDrive if you want the strongest measured torque in the catalogue. Its 700 Nm exceeds 640i MHEV xDrive by 250 Nm, while both reach a recorded 250 km/h. The Diesel has 7 hp more, accelerates 0.1 second quicker, and uses 1.8 L/100 km less combined, although it weighs 100 kg more.

Choose 640i MHEV if acceleration matters more than drive type. It reaches 100 km/h in 5.2 seconds, making it 0.2 seconds quicker than 640i MHEV xDrive despite identical 333 hp and 450 Nm. It also weighs 55 kg less and uses 0.4 L/100 km less combined.

Choose a third-generation 650i 4.4 AT xDrive for the fastest measured 0–100 km/h time. Its 450 hp and 650 Nm deliver 4.5 seconds, but its measured combined consumption reaches 9.3 L/100 km. The 450 hp RWD 650i 4.4 AT is 0.1 second slower and uses 0.7 L/100 km less.

Choose 630Ci 3.0 MT or 650Ci 4.8 MT from the second generation if a naturally aspirated Gasoline engine and Manual gearbox are essential. The 258 hp 630Ci 3.0 MT records 6.5 seconds and 9.0 L/100 km combined; the 367 hp 650Ci 4.8 MT records 5.4 seconds and 11.9 L/100 km in the comparable listing. The extra 109 hp cuts 1.1 seconds from the acceleration time but adds 2.9 L/100 km to combined consumption.

Prices, current sale listings, engine-oil capacity, coolant capacity, reliability, and problems are not measured in the supplied data, so they cannot distinguish the versions here. On the available figures alone, 620d MHEV is the economy choice, 630d MHEV is the balanced RWD Diesel, 640d MHEV xDrive is the torque-led all-rounder, and 650i 4.4 AT xDrive is the acceleration choice.