Back in the 20th century, the era of sporty innovation, very few cars emerged as game changers. Pushing limits farther and farther every day, automakers were determined to beat each other in the domain of speed and sportiness despite the evolving technology. Within that batch of elite cars, there resided a lineup by BMW, which was a complete menace- the Series 8, also nicknamed “the Wedge.” Though the span of this series was short, starting from 1989 and being produced until 1999, this series was one to remember, just like the Porsche 944 or Nissan’s 240x, or the skyline R34 GTR. At the Frankfurt Motor Show in 1989, this luxurious yet feisty series was unveiled.

The legendary 8 Series of BMW had the model E31 with 3 trims.

• E31 850i
• E31 840Ci
• E31 850CSi

The 850i and the 850CSi were both powered by a monstrous V12, whereas the 840Ci was a V8 trim. But the most iconic and impacting trim of the 8 Series was the BMW 850CSi.

History of the 8 Series

As stated earlier, the 8 Series was in production and reigned for 10 years. A total of 30,621 cars made it off the production line, of which 7,232 landed on American soil between 1989 and 1997. The BMW E31, being the product of the 8 Series, had three trims. 850i was the trim available until 1992, when two more trims were introduced in the lineup. These two trims were the 840Ci and the 850CSi.

The 8 Series was first shown at the Frankfurt Motor Show (IAA) in September 1989. It was made to be better than the original 6 Series. The 8 Series had much better performance and cost a lot more.

The 8 Series was the first road car to have a V12 Engine paired with a 6-speed manual transmission.

The 850i was the initial model of the 8 Series, introduced in 1990. It featured a powerful 5.0-liter V12 engine, producing 300 hp.

The 850i became the 850Ci. This change occurred around the introduction of the 840Ci in Autumn 1993.

The 840Ci had two types of engines. The first one had a 4.0-liter M60B40 V8 engine, which could produce 286 hp. This model was made from mid-1993 to late 1995.

The 850CSi, being the top-of-the-range model in the 8 Series, replaced the prototype M8 variant. It shared the same engine as the 850i.

Trims of the 8 Series E31

The rarity of the BMW 850CSi

As the most iconic and influential model of the 8 Series was the BMW 850CSi, it was rare, too. Only 1,510 units of the 850CSi were made from which only 225 units reached the States in the years 1994 and 1995. These numbers indeed speak for the rarity of the 850CSi.

Performance of the 850CSi

Engine of BMW 850CSi

The modifications to the 850CSi from the standard 850i included Bosch Motronic 1.7 fuel injection, an increase in engine capacity to 5.6 L, raising the power output to 375 hp at 5,300 rpm and torque to 550 N⋅m at 4,000 rpm. Road & Track measured the 850CSi's acceleration from 0 to 60 mph at 5.9 seconds.

The 850CSi's version underwent significant enhancements, including lighter pistons, a forged crankshaft, and more aggressive camshafts. The exhaust and intake systems were made more efficient, and the compression was raised. Additionally, heavy-duty engines and differential coolers were added, all thanks to the BMW Motorsport division. These extensive changes earned the engine the prestigious "S" designation code, confirming its official status as a genuine BMW Motorsport product.

Transmission of BMW 850Csi

The 850CSi exclusively came with a long-throw six-speed manual transmission from Getrag. When it was first introduced in the 850i, this gearbox made history as the first six-speed manual paired with a V-12 engine in a production road car. The clutch required some force.

Is the BMW 850CSi an M model? YES!

As we lurk into the history of the BMW 850 CSi, one question is popularly raised: is the 850CSi an M model? Yes, it is. But there is an interesting storyline behind it.

The 850Csi, which was unveiled in 1992, was initially intended to be the M8, which didn't quite happen. The BMW engineers had already prepped the 8 Series M model, the M8, but a change in plans occurred at the end, and all the M8 sauce was given to the 850CSi trim. Interestingly, the BMW 850CSi still owns that M badge as it is still stamped onto it. In short, the BMW 850 CSi is truly an M model developed by the motorsport division of BMW.

Connection to the legendary McLaren F1

The engine used in the BMW 850CSi was a reinforced version of the 850i’s engine. Tuned to be an M motor, this engine, named S70B56, was also the primary platform on which the McLaren F1’s V12 was designed.

Technology introduced

The 8 Series was one of the pioneers in adopting electronic throttle control (drive-by-wire) technology. In the V-12 versions, two ECUs were utilized. To handle the high processing demands of the 8 Series, BMW collaborated with Bosch to develop an entirely new wiring system for all the microcomputers. These computers managed everything, from engine performance to convenience features, enabling the 8 Series to perform intelligent actions like automatically lowering its windows when the doors were opened.

Furthermore, the 8 Series led the way in automobile technology by introducing a Controller Area Network system, connecting microcontroller nodes to various functions without the need for a central host computer.

Aspects of the BMW 850CSi

How does the BMW 850CSi handle?

As the testing from road and track, the car’s dynamic capabilities uphold its heritage. First of all, its quick acceleration, even with those nimble front wheels, grabs the tarmac very well. The car has significantly good controllability and a high chance that you can have fun with it.

We all know what BMWs are famous for, and this car wasn’t revoked because of that factor. You can throw this car sideways as quickly in the dry as it is in wet conditions. With all the control in your hands, the vehicle will slide like it was meant to be doing so with no remorse.

Exterior of the car

The modified suspension with stiffer springs and dampers reduces the ride height. It also had a broader set of wheels with an option for forged M Parallel wheels.

The front and rear bumpers are modified to have more aerodynamic performance.

Big round exhaust tips made from stainless steel take your breath away, and when there are four of them. You can imagine the sound of the car.

The 8 Series underwent enhancements such as upgraded and ventilated brakes featuring floating front discs and redesigned mirrors. Interestingly, in the United States, the cars were distinguished by the presence of "BMW Motorsport" lettering on the door handles.

Interior of the car

The car's interior space is somewhat restricted due to its sleek design, making the 2+2-style rear seating more suitable as a parcel shelf.

However, the interior provides a cozy, cockpit-like feel, complete with BMW's signature driver-focused dashboard, ideal for the two front occupants.

The beautiful leather sports seats offer excellent support and comfort. Moreover, these seats provide great visibility from all angles.

The interior of the CSi is adorned with a variety of colors and textures, including gathered Nappa leather and yew hardwood. This blend of elements adds a sense of warmth, a feature not commonly found in other BMW models. An elegant nod to its heritage can be seen in the subtle stitching on the leather-wrapped steering wheel, featuring a stylish combination of M Motorsport red, blue, and mauve tones.

What do the BMW lovers say?

“Maybe its most serious competitors are others in the BMW 8 Series line.”-Road and Track.

“The 850CSi left me with bittersweet feelings. The 8 Series might be making a comeback, but the march of time and "progress" prohibits us from ever seeing one quite like the original again.”-MotorTrend.

Attributes of the BMW 850CSi

Pros

✔ 0-60 in less than 6 seconds

✔ Strong brakes

✔ Stiffer suspension

✔ Comfort and sports modes

✔ Pop-up headlights

Cons

✖ No 4-wheel steering system in the US

✖ Cooling system problem

✖ Feels wide and bulky.

Features

• Drive by wire control
• Futuristic electronics

Conclusion

Unlike modern robotic cars, the 850CSi offers a natural driving experience, feeling more alive than merely a machine. It embodies the essence of a finely tuned vehicle, seamlessly connecting with the driver as if it were an extension of their body. While the standard 8 Series leans towards being a grand tourer, the 850CSi fully unleashes the potential of its chassis with firmer shocks and springs. Despite its hefty weight and powerful all-aluminum engine under the hood, weighing 4,100 pounds, the 850CSi achieves a remarkable balance. It delivers exact handling, a comfortable ride, unwavering stability, and effortlessly sharp cornering.

It's a beautiful car inside out.

Things to keep in mind if you buy one today.

The 8 Series was undeniably sophisticated in its time. However, given its nearly three-decade lifespan, there are potential issues that might arise now due to aging components and technology.

Checking for rust is crucial, especially for BMW 850 E31 models. Start your inspection from the sunroof area and move along the roof's edge, down to the lower part of the doors and rear wheel arches. Carefully examine every inch for any signs of rust. If you find any, assess its depth to understand the extent of the issue. This proactive approach helps in preventing potential problems associated with rust.

Another common issue with the BMW 850 CSi is faulty suspensions. Fortunately, these problems are relatively easy to detect. If you notice a 'shimmy' between 50 and 60 mph, which you can feel through the steering, it might indicate suspension problems. This symptom can help you identify and address the issue promptly.

Cooling system problems are common in classic BMW E31s. These issues can be caused by an expanded radiator, jammed or loose thermostats, or a faulty water pump. However, diagnosing problems with the water pump can be tricky, as you can't quickly inspect it. It's essential to keep an eye on the overall cooling system, especially if you suspect any overheating or unusual temperature fluctuations. Regular maintenance and checks can help prevent these issues from becoming major problems.

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How much does it cost?

The BMW 850CSi is considered a rare and collectible car today. Don’t think that you’ll get it cheap because it’s an old car. Being a dream of most people, a well-maintained car can easily cost you $100,000 or above.