BMW 8 Series (E31)

Overview

BMW 8 Series (E31)

manufacturer	BMW
production	February 1990‡R1R‡ – May 1999‡R2R‡
successor	BMW 8 Series (G15)
assembly	Germany: Dingolfing‡R3R‡ South Africa: Rosslyn, Pretoria‡R4R‡ (BMW South Africa)
designer	Klaus Kapitza (1986)‡R5R‡
class	Grand tourer (S)
body style	2-door coupé
layout	Front-engine, rear-wheel-drive
engine	Petrol: 4.0 L M60B40 V8 4.4 L M62B44 V8 5.0 L M70B50 V12 5.4 L M73B54 V12 5.6 L S70B56 V12
transmission	5-speed Auto Getrag ZF 5HP24 V8 4-speed Auto Getrag ZF 4HP24 V12 5-speed Auto Getrag ZF 5HP30 V12 6-speed Manual Getrag 420G V8 6-speed Manual Getrag 560G V12
wheelbase	2685 mm‡R6R‡
length	4780 mm
width	1854 mm
height	1330 - 1341 mm
weight	1855 - 1975 kg‡R7R‡
predecessor	BMW 6 Series (E24)

The BMW E31 is the first generation of the BMW 8 Series. It is a grand tourer built by BMW from 1990 to 1999 as a 2-door coupé, powered by either a V8 or V12 engine. Whilst it did supplant the original E24 based 6 Series in 1990, it was not a direct successor, but a new model class with a substantially higher price and performance than the 6 Series.

Development

Development of the 8 Series began in July 1981, with the design phase reaching completion in 1986, although the launch was delayed due to still-strong 6 Series sales.[8] The 8 Series debuted at the Frankfurt Motor Show (IAA) in early September 1989. The 8 Series was designed to move beyond the market of the original 6 Series. The 8 Series had substantially improved performance, as well as a far higher purchase price.

Over 1.5 billion Deutsche Marks were spent on total development ($1.13 billion USD or €990 million in 2025).[9]

Models

The production totals for each model are:[2]

840Ci with the M60 engine: 4,728

840Ci with the M62 engine: 3,075

850i / 850Ci with the M70 engine: 20,072

850Ci with the M73 engine: 1,218

850CSi with the S70 engine: 1,510

840Ci

The 840Ci was offered with two different engines. The first used the 4.0-litre M60B40 V8 engine having a power output of 210 kW and was produced from mid-1993 to late 1995. From mid-1995, production phased in the newer 4.4-litre M62B44 V8 engine, which had better fuel economy and more torque, though power output remained unchanged.

The 840Ci was available with a 5-speed automatic transmission, though European cars were given the option of a 6-speed manual transmission. The only external features distinguishing the V8 model from the V12 models were the quad round exhausts, which were square in the V12 models. The 840Ci stayed in production until May 1999.

850i/Ci

The 850i was the first model of the 8 Series launched in 1990 with the 5.0-litre M70B50 V12 engine having a power output of 220 kW.[13] It was available with either a 4-speed automatic or a 6-speed manual gearbox.

Around the time of the introduction of the 840Ci in Autumn 1993, the 850i was renamed the 850Ci. From October 1994, BMW installed the new M73B54 V12 engine in the 850Ci, the new engine being from the newly launched E38 750i. Thus, cars with 850Ci badging used both the M70 and M73 engines, with those built before 10/94 using the older E32-type M70. As the displacement of the M73 increased to 5.4-litres and the compression ratio went up, the power output increased to 240 kW.

850CSi

As a top-of-the-range variant of the 8 Series, the 850CSi took over from the prototype M8 variant. The 850CSi used the same engine as the 850i, which was tuned so significantly that BMW assigned it a new engine code: S70B56. The modifications included Bosch Motronic 1.7 fuel injection, a capacity increase to 5576 cc and power increase to 280 kW at 5,300 rpm[14] and 550 Nm of torque at 4,000 rpm.[15] Road & Track recorded a 0 - 60 mph time for the 850CSi of 5.9 seconds.[16]

The 850CSi's modified suspension included stiffer springs and dampers that reduced the car's ride height. The recirculating ball steering ratio was dropped 15% over the standard E31 setup. The model also sported staggered throwing star wheels. The front and rear bumpers were reshaped for improved aerodynamic performance. Four round stainless steel exhaust tips replaced the square tips found on other models. The 6-speed manual gearbox was the only transmission option. In Europe, all 850CSi's came with four-wheel steering (AHK - Aktive Hinterachs-Kinematik, Active rear axle Kinematics), upgraded and ventilated brakes with floating front discs, rear differential oil cooler, engine oil cooler, two-tone interior, sports seats, and reshaped mirrors.

BMW 8 Series (E31)

Development

Sales

Models

840Ci

850i/Ci

850CSi

Engines

Transmissions

Prototype models

830i

850i Cabrio

M8

Alpina models

B12 5.0

B12 5.7

Motorsport

References