E28 M5
Production Versions:
DC91: European-spec (LHD), 10/84-9/87
DC92: European-spec (RHD), 03/86-11/87
DC93: North American-spec (LHD), 11/86-11/87
DC98: South African-spec (RHD), 06/87-11/88
History
What makes the E28 M5 unique?
The E28 M5 is the BMW Motorsport-developed version of the E28 5 Series. It uses the M88 or S38 twin-cam 24-valve inline-six first introduced in the M1. It also has a BMW Motorsport-tuned chassis and a few special cosmetic pieces.
Where was the E28 M5 built?
Unlike the normal 5 Series models, M5s were hand-assembled at the BMW Motorsport facility in Garching, a suburb of Munich. Bodies were pressed at the normal Dingolfing factory, then sent to Garching where they were mated with the engine and interior trim. The only exceptions were the South African-spec cars, assembled at BMW's Rosslyn, South Africa factory from German-supplied Complete Knock Down (CKD) kits.
Where was the E28 M5 first introduced?
The M5 debuted at the 1985 Amsterdam Motor Show.
Why was BMW sued by American E28 M5 owners?
When BMW of North America first anounced the E28 M5 in late 1986, production was said to be limited to 500 cars. But by the time production ended in November 1987, however, almost triple that number had been produced. Thus, a class action lawsuit was filed against BMW by E28 M5 owners who claimed that the collector's value of their cars was diminished by the greater volume. The company settled the case by giving these owners a rebate on the purchase of a new BMW.
Why are all North American-spec E28 M5s officially 1988 models if the last example was made in 1987?
This was most likely a marketing decision. With the M5 originally intended to be a limited edition of 500 cars, and with the entire E28 range due to be replaced by the E34 for 1989, perhaps BMW of North America wanted to keep the E28 M5 exclusive by offering it only for the final 1988 model year. Also, it is worth noting that production of the other 1988 5 Series models began in early 1987, so the M5 preceeded these by only a few months.
Why are all North American E28 M5s essentially identical?
Because the E28 M5 was hand-assembled, yet needed to be manufactured for the North American market in relatively large numbers within a relatively short amount of time, BMW of North America was forced to limit the model's specification to just two color schemes: Black (086) with a Natur (tan) leather interior and (officially for Canada only) Black (086) with a black leather interior.
Why is a North American E28 M5 with a black leather interior so rare?
Though a Natur (tan) leather interior was the only official color choice for the U.S. market, Canada insisited on giving E28 M5 buyers the option of a black leather interior. Because all cars for North America (Canada and the U.S.) are built to one specification aside from minor details like metric or non-metric instrumentation, some U.S. dealers were able to special order the black interior. However, it is thought that less than 50 North American M5s with a black interior were produced.
Production Data
How many versions of the E28 M5 were developed?
BMW Motorsport built four different versions of the E28 M5, three at the M works in Garching, Germany (European-spec in left-hand drive and right-hand drive, plus the North American version) and a South African-spec model for the home market assembled from Complete Knock Down (CKD) kits. Only the North American version utilized the catalyst-equipped S38 version of the M88 motor.
How many of each version were produced?
ECE (LHD): 588 built from 10/84 thru 9/87
ECE (RHD): 187 built from 3/86 thru 11/87
NA (LHD): 1,370 built from 11/86 thru 11/87
SA (RHD): 96 assembled from CKD kits from 6/87 thru 11/88*
*Figures indicate final completion date of vehicles assmebled in Rosslyn, South Africa.
Does every example of the E28 M5 utilize a "WBS" VIN prefix?
Starting with the E28 M5, all products from BMW Motorsport GmbH were assigned a "WBS" VIN prefix to distinguish them from the non-M BMW AG vehicles, which retained a "WBA" prefix. However, it is believed that the first 27 left-hand drive ECE examples of the E28 M5 were produced with the regular WBA prefix.
Drivetrain
What makes the M88/S38 engine unique?
The M88 and S38 engines are evolutions of the 24-valve inline-six developed for the mid-engine M1 supercar. Like that engine, both the M88 and S38 have a four-valve crossflow cylinder head (with 37mm inlet valves and 32mm exhaust valves) designed for better breathing at high rpm and a pair of 264-degree camshafts. They also share a displacement of 3,453cc via a bore of 93.4mm and a stroke of 84mm. However, for their application in the E28 M5, the M88 and S38 have unique pistons and connecting rods, as well as a more advanced Bosch ML-Jetronic fuel injection system. To save costs, both engines utilize the standard steel M30 crankshaft and wet-sump lubrication system. Many other smaller items, such as the ignition system, are shared with the regular 5 Series as well.
How do the M88 and S38 engines differ?
The M88 is the non-catalyst version of the S38 engine. With a 10.5:1 compression ratio and a single-row timing chain, it is identical to the one found in the M635CSi coupe. Power is rated at 286 hp (DIN) at 6,500 rpm with 251 lb/ft of torque at 4,500 rpm. The M88 can be identified by the inscription on its cam cover: the propeller Roundel plus the words “BMW” or “M Power.”
The S38 is the “clean” version of the engine, exclusively available in the E28 M5 in North America. It utilizes a duplex (double-row) timing chain and lower 9.8:1 compression designed to work with catalytic converters. This reduced the horsepower to 256 hp (SAE) or 260 hp (DIN) at 6,500 rpm and torque to 243 lb/ft at 4,500 rpm. The S38 has the inscription “BMW M Power” on its cam cover but no Roundel.
What kind of gearbox does the E28 M5 have?
All E28 M5s have the Getrag 280/5 five-speed manual gearbox. Gear ratios are as follows: 3.51 (1), 2.08 (2), 1.35 (3), 1.00 (4), .81 (5). A 3.73:1 final drive is fitted to all but the North American E28 M5, which uses a 3.91:1 rear end. All have limited slip differentials with a maximum locking of 25 percent.
Chassis
How is the suspension of the E28 M5 different from that of a standard 5 Series?
All M5s use the MacPherson strut/semi-trailing arm chassis design common to all E28 5 Series. However, it has been upgraded by BMW Motorsport in the following ways:
-Shorter, stiffer progressive-rate coil springs (not fitted to the North American version)
-Increased steering caster
-Specially-tuned Bilstein shocks
-25mm (front) and 18mm (rear) anti-roll bars
A self-leveling rear suspension was optional in some markets and standard on all North American-spec M5s.
What size brakes does the E28 M5 have?
The E28 M5 has enlarged vented front rotors that measure 11.8-inches (300mm) in diameter. These utilize four-piston calipers. The solid rear rotors are the same as those fitted to an E28 535i or M535i, measuring 11.2-inches (284mm) in diameter. ABS is standard.
What are the E28 M5's factory wheel and tire sizes?
There were two available factory wheel and tire sizes for the E28 M5. Early European-spec cars have metric-sized wheels measuring 195mm x 390mm with 220/55VR390 tires. Later European-spec examples, as well as all those sold in North America and South Africa, have 7.5x16-inch cross-spoke alloy wheels with 225/50VR16 tires, usually Pirelli P700s.
Cosmetics
What distinguishes the exterior of a European-spec E28 M5 from that of a normal 5 Series?
Because the intention of BMW Motorsport was to hide the performance capabilities of the M5 within a standard-looking 5 Series body, there are few external items that differentiate the European-spec E28 M5 from any other E28 sedan. The only body panel that is unique is the black plastic front airdam, included to reduce front end lift at high speeds. There is also an M5-specific aerodynamic engine compartment undertray, body-color rear-view mirror housings and a pair of "M5" badges, one on the grille and another on the trunk-lid, though these could be omitted upon request (which was common). Early examples wear metric-sized alloy wheels (exclusive to the M5 within the E28 series but also offered on the E24 6 Series and E23 7 Series) while most later cars have unique 7.5x16-inch cross-spoke alloys that also include body-color fender lip extensions. Shadowline (dechromed) exterior trim for the window surrounds, bumpers and side moldings was optional.
Later cars were also offered with the M-Technic aerodynamic package as an option. This consisted of body-color extensions with ribbed trim (front bumper and lower airdam, side valance panels, rear bumper and lower diffuser), a rear spoiler and dechromed side moldings. This option could be ordered with or without Shadowline trim but always included the16-inch cross-spoke alloy wheels and body-color fender lip extensions.
How is the interior of an E28 M5 different from that of a regular 5 Series?
Though identical in basic design and layout to that of any E28 5 Series, the interior of the E28 M5 is fitted with a few special items. All examples have a three-spoke M-Technic steering wheel also used in other BMW models. Most are also equipped with sport front seats, though a few were fitted with the standard "comfort" versions by request and some even had genuine Recaro front seats in place of the BMW items. In some markets, both the front and rear seats include an M tri-color stripe attached to a metal tag. On the earliest cars, the leather shift knob is topped with only an "M" logo. This was soon changed to a version with both the standard shift pattern and the tri-color M stripe. The instrument cluster contains a unique 280 kph/170 mph speedometer and a special tachometer with the M logo instead of an economy meter. A black headliner is exclusive to the M5 within the E28 range and later examples also have special door sill plates with the "M5" logo. Finally, the trunk of the E28 M5 is unique for four reasons. First, it contains the battery in a special right-side compartment, secured by one of two different covers, depending on the production date. Second, it is lined with a plush carpet. Third, with the exception of the earliest examples, the lining on the inside of the trunk lid is black instead of the usual light grey. Finally, there is a special cargo net to secure loose objectrs, though this also does not appear to have been fitted to the earliest cars.
What features were optional on the European-spec E28 M5?
Because the E28 M5 was assembled largely by hand at the BMW Motorsport facility, European customers could not only choose from the entire range of normal E28 options but also request more specialized features like hand-stitched complete leather interiors and/or integrated electronics such as phones, faxes, and minibars. Thus, depending on the market and production date, the E28 M5 could be very sparsely equipped or extremely luxurious. However, every E28 M5 features power front windows, power mirrors, central locking, and the Check Control vehicle function monitoring system. Options varied from market to market but generally included metallic paint, Shadowline (dechromed) exterior trim, headlight washer/wipers, leather upholstery (in various grades), air conditioning, the on-board computer II, power front seats, heated front seats, power sunroof, rear window sunshade, rear headrests and various audio systems.
How is a North American-spec E28 M5 cosmetically different from a Euro-spec E28 M5?
The North American-spec E28 M5 uses the same government-mandated sealed-beam headlights (all four of the same diameter) and 5-mph bumpers with integrated side marker lights as all U.S. and Canadian versions of the E28 5 Series. However, the M5 adds a special front airdam designed specifically for the North American front bumper as well as the M-Technic rear spoiler fitted as an option to some European-spec examples. Though these items are not unique to this model (both are also found on the E28 535is), the M5 can further be identified by its Shadowline trim, "M5" grille and trunk-lid badges plus the 16-inch cross-spoke alloy wheels.
How is the interior of the North American E28 M5 different from that of the European version?
Unlike the wide variation of color, trim and equipment found in European-spec E28 M5s, all North Americans-spec interiors have Black or Natur leather sport seats, with additonal hide on the seats, center console, glovebox door and door pulls. In addition, all have the M tri-color seat stripes (front and rear) and "M5" door sill plates, while the carpeted trunk always features the black lid lining, cargo net, later-style battery box enclosure and left-side storage compartment. Standard equipment includes air conditioning, power seats, power sunroof, cruise control and an eight-speaker am/fm cassette stereo system. Heated front seats were the only factory option (standard in Canada).
Special Versions
Were there any special versions of the E28 M5?
There were no special editions of the German-built E28 M5. However, a limited run (96 cars) of M5s was assembled in South Africa exclusively for that market.
What distinguishes the South African E28 M5 from the German-built version?
The 96 right-hand drive E28 M5s produced for the South African market were assembled at the Rosslyn, South Africa factory using German-made Complete Knock Down (CKD) kits. The mechancal items are thus identical to those of the European-spec E28 M5.
Cosmeticaly, however, the South African E28 M5 is somewhat unique. All are equipped with the M-Technic body panels that could be ordered as an option in some European markets, as well as Shadowline trim and the 7.5x16-inch cross spoke alloy wheels. But because the South African E28 M5s were painted in the local paint shop, exterior colors were limited to five choices: Henna Red (052), Ice White (?), Cirrus Blue metallic (189), Delphin Gray metallic (184) and Diamond Black metallic (181).
On the inside, all South African E28 M5s have essentially every normal 5 Series luxury item as standard, the only optional extra being a power sunroof. Unique to the South African version is a complete “Highline” Nappa leather interior normally offered only in E24 6 Series and E23 7 Series models. This includes Nappa leather on the seats, door panels, center console, glovebox door, headliner, sun visors, upper door trim and dashboard. There are also the usual M tri-color insignias on the front and rear seats. This interior was available in Lotus (white), Natur (tan), Midsilver (gray) and Indigo (dark blue). Finally, South African-spec models are not equipped with the black inner trunk lid liner used on all but the earliest German-built E28 M5s, though they do utilize the black trunk carpeting.
Color and Upholstery Selections
Exterior Colors (European-spec):
Black (086), Alpine White (146), Cinnabar Red (138), Lapis Blue (173), Polaris Silver metallic (060), Salmon Silver metallic (203), Bronzit metallic (139), Delphin metallic (184), Arctic Blue metallic (045), Cirrus Blue metallic (189), Cosmos Blue metallic (185), Royal Blue metallic(198), Agate Green metallic (177), Malachite Green metallic (205), Sable Brown metallic (196), Diamond Black metallic (181)
Note: Because of the hand-built nature of the E28 M5, all other existing BMW exterior colors and any other special exterior colors could generally be requested for an extra fee.
Exterior Colors (North American-spec):
Black (086)
Interior Colors (European-spec):
Anthracite Highland Cloth, Pearl Beige Highland Cloth, Pacific Blue Highland Cloth, Pine Green Highland Cloth, Nutria Highland Cloth. Black leather, Pearl Beige leather, Natur leather, Pacific Blue leather, Nutria leather, Lama leather, Cardinal Red leather, Silver leather, Anthracite Buffalo leather
Note: Most interior colors were offered in a choice of standard leather (seats only), extended leather (center console, glovebox, door pulls) or, by special request, complete leather (dashboard, A-pillars, sunvisors, steering wheel boss).
Interior Colors (North American-spec):
Natur extended leather (U.S. and Canada), Black extended leather (officially only for Canada)