BMW 6 Series (E24)

The BMW E24 series was the first BMW 6 Series coupé, produced by the German automaker BMW between the 1976 and 1989 model years. The 6 Series name reappeared with the BMW E63 chassis beginning in the 2004 model year. The E24 borrowed heavily from contemporary 5-series cars (E12, later E28).

Model history

The E24 was a replacement for the CS and CSL coupés first produced in 1965. The CS 3.0 was almost changed by adding a few centimeters in height to make it easier for customers to get into the car. However, Bob Lutz rebelled against the decision and rough drafted an alternative version that soon became the 6 series. Production started in March 1976 with two models: the 630CS and 633CSi. Originally the bodies were manufactured by Karmann, but production was later taken in-house to BMW.

In July 1978 a more powerful variant, the 635CSi, was introduced (for the time being not available in North America and Japan) that featured as standard a special close-ratio 5-speed gearbox and a black rear spoiler.

In 1979 the carburetted 630CS was replaced with the 628CSi; this car had a fuel injected 2.8L engine taken from the BMW 528i.

In 1982 (Europe) and 1983 (US), the E24 changed slightly, with an improved interior and slightly modified exterior. At the same time, the 635CSi received a new engine, a slightly smaller-bored and longer-stroked 3430 cc six to replace the former 3453 cc engine and became available with a wide-ratio 5-speed or an automatic.

E24s produced after June 1987 came with new, ellipsoid headlamps which projects beam more directly onto road surface (newly introduced E32 series also sporting them). The sleeker European bumpers were also discontinued. Previous cars had either a European-standard bumper or a larger, reinforced bumper to meet the US standard requiring bumpers to withstand impact at 5 mph (8 km/h) without damage to safety-related components. 1989 was the last year for the E24 with production stopping in April. The E24 was supplanted by the considerably heavier, more complex, and more exclusive E31.

M version

BMW Motorsport introduced M 635 CSi in Europe at the Frankfurt Motor Show in 1983. It is essentially an E24 powered by the powerplant of the BMW M1 - the M88 (286 PS (210 kW; 282 hp)). Most of the cars were equipped with special metric 415 mm diameter wheels requiring Michelin TRX tires. A catalyzed, lower compression ratio version of the car with the S38 engine (260 PS (190 kW; 260 hp)) was introduced in the U.S. in 1987. All M6 cars came standard with a 25% rear limited slip differential. U.S. models included additional comforts that were usually optional on models sold in Europe such as Nappa leather power seats and a dedicated rear A/C unit with a center beverage chiller. Car and Driver tested a U.S. M6 in July 1987 and achieved a 0-60 time of 6.1 seconds, better than the BMW published 6.4 and 6.8 second times for the European and U.S. versions respectively. 4,088 M 635CSi cars were built between 1983 and 1988 with 1,767 U.S. M6 built.

Models timeline

BMW E24 timeline

Type	1970s										1980s
	0	1	2	3	4	5	6	7	8	9	0	1	2	3	4	5	6	7	8	9
630 CS
633 CSi
630 CSi (US)
633 CSi (US)
635 CSi
628 CSi
M 635 CSi
635 CSi (US)
L6 (US)
M6 (US)

Technical data

Technical data BMW 628CSi-M 635CSi (E24) (except North America and Japan) (Manufacturer's figures except where stated)

BMW	628 CSi	630 CS	633 CSi	635 CSi	635 CSi	M 635 CSi
Produced:	1979–1987	1976–1979	1976–1982	1978–1981	1982–1989	1983–1989
Engine:	6-cylinder-inline engine (four-stroke), front-mounted
Bore × Stroke:	86 mm × 80 mm	89 mm × 80 mm	89 mm x 86 mm	93.4 mm x 84 mm	92 mm × 86 mm	93.4 mm × 84 mm
Displacement:	2788 cc	2985 cc	3210 cc	3453 cc	3430 cc	3453 cc
Max. Power @ rpm:	184 PS (135 kW; 181 hp) @ 5800	185 PS (136 kW; 182 hp) @ 5800	197 PS (145 kW; 194 hp) @ 5500	218 PS (160 kW; 215 hp) @ 5200	218 PS (160 kW; 215 hp) @ 5200	286 PS (210 kW; 282 hp) @ 6500
Max. Torque @ rpm:	235 N·m (173 lb·ft) @ 4200	255 N·m (188 lb·ft) @ 3500	284 N·m (209 lb·ft) @ 4300	304 N·m (224 lb·ft) @ 4000	304 N·m (224 lb·ft) @ 4000	333 N·m (246 lb·ft) @ 4500
Compression Ratio:	9.3: 1	9.0 : 1	9.3 : 1	9.3 : 1	10.0 : 1	10.5 : 1
Fuel feed:	fuel injection Bosch L-Jetronic	downdraft carburetor Pierburg 4A1	fuel injection Bosch L-Jetronic		fuel injection Bosch Motronic
Fuel tank capacity:	70 L (18.5 US gal; 15.4 imp gal)
Valvetrain:	12 valves, SOHC, duplex chain					24 valves, DOHC, duplex chain
Cooling:	Water
Gearbox:	4-speed manual, from 1979 5-speed manual (wide- or close-ratio) on request 3-speed automatic, from 1983 4-speed automatic rear wheel drive					5-speed manual rear wheel drive
Electrical system:	12 volt
Front suspension:	McPherson axle, coil springs, stabilising bar
Rear suspension::	Trailing arms, struts, coil springs, stabilising bar
Brakes:	disc brakes (Ø front 280 mm, rear 272 mm), power assisted, from MY 1984: ABS
Steering:	ZF recirculating ball steering, power assisted
Body structure:	Sheet steel, unibody construction
Dry weight:	1,450 kg (3,200 lb)	1,475 kg (3,250 lb)	1,495 kg (3,300 lb)	1,520 kg (3,400 lb)	1,470 kg (3,200 lb)	1,510 kg (3,300 lb)
Loaded weight:	1,830 kg (4,000 lb)	1,830 kg (4,000 lb)	1,830 kg (4,000 lb)	1,860 kg (4,100 lb)	1,850 kg (4,100 lb)	1,850 kg (4,100 lb)
Track front/ rear:	1,422 mm (56.0 in) 1,487 mm (58.5 in)	1,422 mm (56.0 in) 1,487 mm (58.5 in)	1,422 mm (56.0 in) 1,487 mm (58.5 in)	1,430 mm (56 in) 1,460 mm (57 in)	1,430 mm (56 in) 1,460 mm (57 in)	1,430 mm (56 in) 1,464 mm (57.6 in)
Wheelbase:	2,626 mm (103.4 in)	2,626 mm (103.4 in)	2,626 mm (103.4 in)	2,626 mm (103.4 in)	2,626 mm (103.4 in)	2,626 mm (103.4 in)
Length:	4,755 mm (187.2 in)	4,755 mm (187.2 in)	4,755 mm (187.2 in)	4,755 mm (187.2 in)	4,755 mm (187.2 in)	4,755 mm (187.2 in)
Width:	1,725 mm (67.9 in)	1,725 mm (67.9 in)	1,725 mm (67.9 in)	1,725 mm (67.9 in)	1,725 mm (67.9 in)	1,725 mm (67.9 in)
Height:	1,365 mm (53.7 in)	1,365 mm (53.7 in)	1,365 mm (53.7 in)	1,365 mm (53.7 in)	1,365 mm (53.7 in)	1,354 mm (53.3 in)
Tyre/Tire sizes:	195/70VR14	195/70VR14	195/70VR14	195/70VR14	205/70VR14	220/55VR390 or 240/45VR415
Top speed:	215 km/h (134 mph)	210 km/h (130 mph)	215 km/h (134 mph)	222 km/h (138 mph)	225 km/h (140 mph)	255 km/h (158 mph)
Fuel Consumption (estimates):	15.5 litres per 100 kilometres (18.2 mpg-imp; 15.2 mpg-US)	16.5 litres per 100 kilometres (17.1 mpg-imp; 14.3 mpg-US)	16.5 litres per 100 kilometres (17.1 mpg-imp; 14.3 mpg-US)	17.0 litres per 100 kilometres (16.6 mpg-imp; 13.8 mpg-US)	15.0 litres per 100 kilometres (18.8 mpg-imp; 15.7 mpg-US)	18.0 litres per 100 kilometres (15.7 mpg-imp; 13.1 mpg-US)

Models for North America and Japan

While in most markets several E24 versions were usually available, markets with strict emission control regulations received only a single model (except for the M6 that was later offered additionally). This meant that in North America and Japan, BMW offered the following models:

• 630CSi (MY 1977 through 1978½)
• 633CSi (MY 1978½ through 1984)
• 635CSi (MY 1985 through 1989)
• L6 (MY 1987 - Luxury Edition 635CSi NA-only)
• M6 (MY 1987 through 1989)

In 1977, the 6er was released in the US as the 630CSi. This was a fuel-injected version of the carburetted 630CS available elsewhere. Its 3-litre engine developed 176 horsepower (131 kW) and 185 ft·lbf (251 N·m) of torque.

In mid-model year 1978 the 630CSi was replaced by the 633CSi. US/Japan specification 633CSi cars had the M30 3.2 litre 181 hp (135 kW) engine until 1984. In 1985 the car was renamed 635CSi, displacement was increased to 3.4 litres and horsepower increased slightly to 182 hp (136 kW). The big difference, however, was torque. Whereas the 3.2 litre had 195 ft·lbf (264 N·m) at 4,000 rpm, the 3.4 litre powerplant managed 214 ft·lbf (290 N·m) at 4,000 rpm.

From model year 1983, North American and Japanese versions benefitted from the technical revisions and changes to the interior introduced elsewhere in spring or summer 1982. Its chassis was now based on the E28 and no longer on the E12. The front and rear suspension was also revised. Later a self-levelling rear suspension was added to the 635 CSi and M6 features list in 1988.

The US received its own M series E24 in 1987 called the M6. The S38 powerplant found in the US model had several modifications from the M88 powerplant in the European model, most notably: a double row timing chain, modified cam tray, different valve lengths, a slightly different cam profile, less elaborate exhaust manifold (rather than full headers), Bosch X5DC copper spark plugs (instead of Bosch Silver plugs on the M88) and the introduction of an oxygen sensor for the EFI. These changes coupled with the introduction of a catalytic converter for emission regulations reduced the output to 256 hp (191 kW). The US model also included a variety of options usually of which were optional on European models, to include: heated power seats, sport tuned self-levelling rear suspension, A/C cooled ice box between the rear seats, A/C vents for rear seat occupants, sunshade for rear occupants and an 8 speaker "premium" sound system.

In 1988, the US E24 was now available with the newest version of the M30, the 3.4L (first used in the E32 735i). Even though the intake manifold states 3.5 it's technically a 3.4 (3430cc) like the previous 3.4. This engine had an increased compression ratio, and updated Motronics/DME. The result was 208 hp (155 kW) and 225 ft·lbf (305 N·m) torque. In effect, this engine was identical to the catalyzed version newly available in Germany and other markets.