To build the best product, you have to set technical goals. Those goals are based on a number of factors, including what the competition is doing and also what the “ideal” is. For many suspension engineers, the “ideal” has always been the BMW E39 5 Series. Here’s why it’s so good that it’s been studied under suspension engineers’ microscopes for over 30 years.
Let’s first talk about why suspension engineers would bother looking at another company’s cars in the first place. It all begins with defining the customer of your new vehicle program.
Defining The Customer
When a car company starts to develop a new car, one of the first things it does is define who is likely to buy that car. The company needs to know who the customer is so they can target their product to the right buyers.
Vast storyboards are created showing the lifestyle these customers live, their income, where they live, what activities they like to participate in. Are they single or do they have a family? How big is the family? Do they drive lots of kids and their friends to soccer practice? Do they take their car to track days? Are they active? Are they retired? Are they into natural foods or do they go to fast food places? Many of these things have nothing to do with cars specifically, but they give a broad picture of the type of person a company intends to attract with its product.
Here’s an example for the Subaru Crosstrek; its customers are described simply as “Youthful Explorers”:
Knowing your customers also means knowing what other cars they are likely to buy or consider. You have to ask yourself the question: “If our car were out today, what other cars would our customers cross-shop and what would influence their purchasing decisions?” From this discussion comes a list of potential competitive vehicles your customers may buy instead of yours.
The Competition
Naturally, the market segment your car will enter has a great influence on the customer and the competitive vehicles you choose. If you are planning to compete with the Toyota Corolla, your storyboards and vehicle list will be completely different than if you plan to compete with a Mercedes-Maybach.
As the planning process is taking place, the company will begin forming the various engineering teams that will be needed to design the new product. A management structure will be created to lead the project with a single person — a chief engineer — at the top who is responsible for delivering the final product. Every company has their own way of doing this, but the result is a group of engineers and managers in each of the major functional areas assigned to work on the new project: Body systems, Chassis systems, Interior, Exterior, Powertrain, Electrical, etc. as well as the various attribute areas: Vehicle Dynamics, Safety, Noise Vibration and Harshness (NVH), Ergonomics, Package, Regulatory Compliance, etc.
[Editor’s Note: At Chrysler, engineering was broken up into what was called BICEEPR: Body, Interior, Chassis, Electrical, Engine Systems, Powertrain, Restraints. -DT]
Each team will start out small — only a few people at most — and grow over time as the work progresses.
The work of creating the storyboards and defining the competitive vehicles is usually done by the sales and marketing teams in conjunction with the styling/design studio. There is little, if any, engineering input into this part of the process. However, that changes once a list of potential competitive vehicles has been identified. The program management team will go out and buy the top three to four competitive vehicles and the engineering teams will spend the next few months thoroughly analyzing them, measuring them, driving them, and figuring out why they work as well as they do. These vehicles will remain with the team for the duration of the program to be used as a reference as the design and eventually prototype testing develops.
Some OEMs will also take this time to determine on what level they would like to compete in the marketplace. This will depend on the type of manufacturer it is and how they have placed themselves in the market. If the OEM has built a reputation for engineering excellence, they may want to be the leader in vehicle dynamics, ride, or durability. If the OEM has instead built a reputation for value, then they may want to make sure they deliver a product at the lowest price while still offering acceptable ride/handling/durability attributes. Some OEMs may place more value on safety, demanding that their new product achieves five stars in all crash tests even if that requires a sacrifice to ride/handling/vehicle dynamics. It really depends on the OEM, how they have built their reputation, and what they perceive is important (and not important) to their customers.
Benchmarking
The process of understanding how good your competitive vehicles are is called Benchmarking. Benchmarking takes many forms depending on what you are trying to understand (ex: Munro and Associates tears cars down to find out how they’re built and how much it costs to build them), but the most basic form is to simply go out and drive the cars. This can be done on an individual basis or as a group.
I have spent many days in my career on benchmarking drives where we gather a number of competitive vehicles, go out to a remote location that has a variety of roads, and drive the cars. Someone would have gone out several days or weeks before and mapped out a route that would include some highway sections, twisty roads, rough pavement, and opportunities to do some hard braking and acceleration. Each driver would rotate through all the cars and rate them on many different attributes: ride, handling, interior noise, seat comfort, ergonomics, power, brake feel, steering feel, etc. There would be several dozen categories and sub-categories, and you would be expected to provide your opinion in the form of a rating on each one. (Side note here: We would always buy competitive vehicles in grey or silver, never a bright color like red. Red cars always rate better and can skew the results. Engineers try hard to be impartial, but the reality is that we still have our biases. We like red cars.)
The ratings scales would depend on what is being evaluated. Most often, a scale from 1-10 is used where 1 is unacceptably bad and 10 is unbelievably good. The Society of Automotive Engineers developed such a scale as part of its J1060 “Subjective Rating Scale for Evaluation of Noise and Ride Comfort Characteristics Related to Motor Vehicle Tires” standard which I have used in all the OEMs I have worked for:
While this scale goes from 1-10, the reality is that we would never give anything a rating below five or above nine. Nothing is so good that it deserves a 10, and nothing is so bad that it deserves a rating below five. After all, the cars we are driving are all being sold so they are clearly not “unacceptable.” Plus, we weren’t benchmarking the worst cars in the class.
Such a scale doesn’t work in all cases though since vehicle attributes are so subjective. If you are rating brake pedal effort, for example, one driver may prefer a very light pedal while another prefers a heavy pedal. Using a 1-10 rating scale would not be very useful in that case. In those instances, we would use a scale from one to five where one might be very light and five might be very heavy. This way, personal preferences are captured and can be reflected in the data.
Usually, we would use a team of about ten engineers driving five cars, and the process would take a full day or even several days to complete. The results would then be tabulated and averaged, and the responsible team would write a report with the results.
Measurements
Another form of benchmarking is objective measurements. Here, the cars are run on a variety of roads and measured using various instrumentation. The NVH teams, for instance, will place a recording device and accelerometers inside and throughout the vehicle to record the noise and vibrations while driving over known rough surfaces, often at a test track.
The vehicle dynamics team will have a highly trained driver take the car on a very large asphalt surface called a VDA (Vehicle Dynamics Area or “Asphalt Lake”) through a variety of maneuvers like lane changes, step steer events (where you violently turn the wheel 90 degrees and hold it), max braking events, etc.
Some OEMs may even use driving robots to do these tests so that each car has exactly the same inputs every time.
A specially designed handling course will be used to drive the cars at their limit to see how easy the car is to control and how well “ADAS” electronic systems like stability control function.
During these tests, the responses of the cars are measured with accelerometers, GPS locators, height sensors, and other instrumentation to see how each car performed. The results are then tabulated, plotted, and compared against each other.
Some measurements may require highly specialized machines. Suspension engineers, for instance, will use a machine called a Kinematics and Compliance machine to push and pull on the suspension. This video shows one of these machines in action:
From these measurements, engineers can tell how the camber, toe, and caster change when the suspension is moved up and down, steered, or gets pushed and pulled like it would be during cornering or braking events. This data is invaluable to understanding why a particular car rides and handles the way it does.
Once all the data from subjective drives and objective tests is collected, engineers use it to decide how well they want their new product to function based on in what areas the company wants the product to be a leader (or just be competitive).
Futuring
Of course, deciding to be competitive or a leader compared to what is out there today will never be good enough. Benchmarking by definition is really just looking into the past. The vehicles you can buy today are the results of those OEMs using this same process four to five years ago. Those same OEMs are not standing still, and when your new car goes into production four to five years from now, those cars will have improved. So, if you are just competitive with what is out there today, you will be uncompetitive once your product enters production.
The trick is to look at the improvements that have happened over the past decades and extrapolate them into the future: a process called “futuring.” It sounds simple, but it is extremely hard, and not many people are good at it. The process also by definition looks at historical trends and cannot account for innovations that can completely change the marketplace. No one in 1979 knew that the world’s major producers of oil would reduce their production and cause a worldwide crisis that changed many customers’ buying decisions away from large gas hogs and towards smaller more fuel-efficient cars. No one in 1990 knew that Toyota was going to come out with its Lexus brand and rewrite the rules of what a luxury car could be and more importantly, what the whole customer experience could be. No one in 2011 knew that Tesla was going to come out with an EV that would make a typical ICE car feel like an old dinosaur.
No one can future against these sorts of events, but fortunately for those doing the benchmarking, they are rare. For the most part, the auto industry improves in small increments, and it is possible to look into a crystal ball and get some idea of where things will be four to five years from now. You can then use this information to decide how much better your car will need to be to remain competitive or still be a leader once it goes on sale. It goes without saying that knowing how good you want to be still requires translation into the hardware that will achieve those targets, and this is done through a process called a “target cascade.”
Target Cascade
Let’s look at an example of a target cascade. Suppose we were developing a car and the characteristics we were most interested in were Fuel Economy, Value, Performance, Safety, Durability, and Package. We’ve identified three competitive vehicles — A, B, and C — which we have bought and tested. After completing our benchmarking of competitive vehicles, we could summarize the results in the form of a spider chart (sometimes also called a radar chart) like this:
We can easily see how each competitive vehicle compares to the others for each of the characteristics we’ve chosen to focus on. In addition, we can add where we want our own car to be in relation to those vehicles. Of course, these are purely fictitious numbers. Expecting our new car to achieve a rating of nine for everything is probably unrealistic, but you get the idea.
We can now focus on each area individually. If we looked at Performance specifically, we might break it down into 0-60 time, Braking, Handling, Steering, and Ride like this:
We could then drill down even further. Looking at Steering, we could break it down into On-Center Feel, Effort, Linearity, Vehicle Response, and Returnability like this:
Going even further, we could look at On-Center Feel and break it down into Steering Gear Ratio, Pull-through Friction, Intermediate Shaft Torsional Stiffness, and Gain. We are now getting to the point where we are talking about characteristics to which we could potentially assign an objective, measurable number — one that we could provide to a supplier or engineering team to use in the design of a component. And that’s what we ideally want to get to: numbers that can be used to guide the design of the components of the car.
Once the design is completed, these numbers, and the cascade that got us there, create a direct way to evaluate how well we did. When computer models and later prototype vehicles are built, their performance can be compared with the targets, and we can decide if we think we’ve achieved our top-level goals.
The Best Car
Having been through this process many times during my 32 years in the auto industry, I have driven competitive vehicles of all types: small sedans, large sedans, high-end sports cars, SUV’s, pickup trucks, top-end luxury cars, and on and on. From cheap Corolla competitors to Rolls-Royces, I’ve had the opportunity to drive it all. But the one car that has consistently stood out to me time and time again was the E39 BMW 5-series.
I know for a fact I am not alone in feeling this way. During my career, many engineers, especially vehicle dynamics engineers, owned these cars. In many cases, the competitive vehicle sets for the new car programs I worked on included the E39 or its predecessor. In fact, the incredibly advanced, all-electric Lucid Air, which launched for the 2022 model year, used the nearly 30-year-old car as a benchmark, per Motor Trend. From the car site:
As a Lotus alum, Lucid Motors CEO and CTO Peter Rawlinson wanted his Lucid Air electric luxury sedan to at least invoke the feeling of nimbleness and linearity of responses to control inputs without latency or phase lags that the iconic Lotus cars are known for.
[…]
Obvious benchmark vehicles for the Lucid Air’s dynamic handling included Porsche’s Panamera and Taycan, while more attainable benchmark cars Lucid purchased for study were a Chevy SS and an E39 BMW 5 Series. Each of these vehicles features modest levels of ultimate grip but feel very playful as they approach them.
When the programs I worked on tested the E39 5 Series, the vehicle consistently rated at the top of almost all functional categories, and really became the benchmark we all tried to achieve. To this day, I have not driven a car that has such a perfect combination of ride, handling, comfort and utility as the E39. The car was exceptional in twisty backroads but was also relaxing to drive on the highway. The faster you drove, the easier the car was to control.
Making a suspension great is a combination of the right tires, springs, damper settings, and bushing tuning. It’s a combination of many small details, There is no magic bullet that makes a suspension great. Of course, you need a good suspension geometry first but good tuning on the tires, springs, and dampers can make up for a lot. As an example, for decades Porsche used a very simple MacPherson strut in the front of the 911, as did BMW with the 3 and 5-series. Simple but very well executed. At that time, BMW were masters at finding the right combination of these factors and the designers of the E39 managed to find that perfect balance.
Most other cars that were fun in the twisties were darty or nervous on the highway. Not the E39. On top of that, you could put five people and their luggage in it. I never did entirely figure out how BMW managed to achieve all of that, but I’m glad they did. But if there’s one obvious piece, one little bit of the secret sauce that makes the E39 just feel right it’s something called an “Integral Link” and it is a unique design different from any other suspension.
It uses a small vertical link in the rear suspension between the lower arm and the knuckle to control wind-up during braking. The whole design is very compact. If you watch the video above you’ll see how it works and where it is. The downside is that it doesn’t allow for very much rear steer which is why you see some companies moving away from
I feel that no one, not even BMW, has bested this car in the years since. All the electronic gizmos and bells and whistles available today cannot make up for the fact that the E39 was so fundamentally good that it didn’t need those devices to be a great car.
It didn’t need infinitely adjustable shocks, or dynamic stability control, or cameras that looked at the road ahead, or lane keeping assist, or extreme low-profile tires, or any other toy to be an absolute joy to drive. BMW nailed the fundamentals of what makes a car great with the E39, and the result was a car that was at the top of every engineer’s wish list. I have spoken to and worked with many engineers from other OEMs, and my feelings are universally shared.
So, if you plan on starting your own car company or are working for an OEM starting a new car project, you can go through a massive benchmarking activity that will cost you millions. Or… you can go out and buy an E39 BMW for a few grand and be done with it.
Incredible technical explanation! I really do think this has generally been the secret sauce on 80s-00s BMWs and in my limited experience Porsche, is that sense of the car coming alive and shrinking around you and getting better as you push it. Yet feel basically like a normal car when you’re toodling around. I do think the reason BMW at least moved away from this is their controls etc feel a tad on the “heavy” side in regular driving vs the typical Japanese or American car and from having talked to some people who’d ridden in bmws and “didn’t get it” they don’t feel that special until you are blasting through corners with them or cruising at 80 mph.
This is a great article, but I gotta say, this is one of the most interesting tidbits:
(Side note here: We would always buy competitive vehicles in grey or silver, never a bright color like red. Red cars always rate better and can skew the results. Engineers try hard to be impartial, but the reality is that we still have our biases. We like red cars.)
I was part of a team of engineers scoring exhaust systems for subjective noise, which involved driving round a track and rating them for how fun they sounded. Sometimes engineering is fun.
It was supposed to be a blind test but I’d designed the systems so I knew which car had which exhaust by half way through, and I was deeply upset that the concept marketing liked (but I disliked for a number of engineering reasons, but also because marketing liked it) had been fitted to a red car.
The red car won.
That’s bananas!
However…
Did the exhaust that the marketing department liked on the red car win because it was a red car, or because the marketing department knows what people like?
Urgh, I hadn’t even considered that they might be right.
What if they aren’t shallow morons constantly stealing the latest trends from each other but are instead actual useful humans?
I’ll observe some this afternoon, see if they are artfully concealing competence.
I remember reading an article years back, about how Mercedes tuned the exhaust on AMGs by strapping biometric sensors on test drivers, had them got WOT on the autobahn, and looked for an exhaust note that would produce a slight rise in heart rate when heard
Might be one of the most German things I’ve ever heard
I love that!
A way to test the “red car” theory would be to mount the same exact system to a silver car and a red car, and have people then evaluate at which is “better”.
Excellent article! The subjective rating system made me laugh as I’ve dealt with it a lot before for NVH issues. The ratings never go below a 5 and never above an 8, even though 9 and 10 technically meant the issue was inaudible. We’d have data showing that the gear noise or whatever for a particular car was impossible to hear, but it would never rate higher than an 8. We also had situations where engineers would rate things at 6.8 or 7.1 which makes no sense on a subjective scale. One of the engineers poked fun at this by giving crazy ratings like 7.3454.
I had to rebuild an e39 suspension and never knew what that integral link was for, so appreciate the knowledge!
Great insight into how OEM vehicle development programs work!
“No one in 1979 knew that the world’s major producers of oil would reduce their production and cause a worldwide crisis that changed many customers’ buying decisions away from large gas hogs and towards smaller more fuel-efficient cars.”
Yes we did. We all did. That happened in 1973. I remember I needed gas for m’car. So I decided to go to Morganville, which is what they called Shelbyville in those days. So I tied an onion to my belt, which was the style at the time. Now, a gallon cost ten nickels, and in those days, nickels had pictures of bumblebees on ’em. “Gimme five bees for a quarter,” you’d say. Now where were we… oh yeah. The important thing was that I had an onion on my belt, which was the style at the time. I didn’t have any white onions, because of the war in Vietnam. The only thing you could get was those big yellow ones…
Stability control is not an ADAS function…
I drove a 2001 530i for a week while visiting relatives.
It’s still the best car I’ve ever driven, by a pretty decent margin. Everything about it was flawless.
This makes me wonder, is this the greatest car of all time?
I didn’t think this was an answerable question until I read this article. Now I want to watch car playoff series that somehow turns benchmarking into an exciting competition that will determine what the actual greatest all around car of all time is.
Kind of like top gear, without the celebrity cameos.
Youthful explorer? How about the REAL customers? Those whose “passions” are eating crappy fast food, couch surfing, porn watching, pimple popping, internet shopping, weight gaining, commentariat participating, hypertension and diabetes denying etc.
Well at least they got “video games” right.
Subaru owners: 0% Gen X?, 0% Boomer??, 0% Parents???
Real people living real lives need not apply.
Another great article! Especially the description of the E39.I’ve heard much praise of BMWs over the decades but rarely does anyone give a full explanation of how and why
Huibert is so good at explaining mysterious things!
David:
> At Chrysler, engineering was broken up into what was called BICEEPR: Body, Interior, Chassis, Electrical, Engine Systems, Powertrain, Restraints
Why Restraints and not Safety? I mean BICEEPS was RIGHT THERE.
I want to hear stories about the benchmark cars and subjective test drives for the Ford GT. Those must have been a fun (and maybe terrifying) couple of days.
Mmmmmm <scratches his chin>
I owned an E39 528i. The suspension really was superb. Even with 18 inch M5 wheels and loaded up or unloaded, it was always compliant and handled extremely well. I only ended up selling it due to the litre of synthetic oil it burned through each week and the constant plastic parts in the engine bay breaking.
Two words:
LS swap.
I saw someone swap in a TB48DE from a Nissan Patrol in one once, it was a beast. But yeah LS swap is the go to option.
So 10 years ago Kia in Australia was trying to find a way of being different to their bigger brother Hyundai.
They engaged a guy to do a local suspension tune. Australian roads are crap and our speed limits fairly low (110 kph max) as opposed to Korea higher quality roads. They employ Graeme Gambold, ex rally racer and mechanic. He did suspension tunes for the Kia for Australia and those spring and shock rates were adopted for all Australian Kias….. and now Australia Hyundai as well.
Guess what Graeme is a fan of…. and actually drives as I found out via another website… E39.
https://www.drive.com.au/caradvice/the-secrets-behind-kias-local-suspension-tune-by-the-engineer-responsible-interview/
Correct me if I’m wrong, but derived from the revolutionary M.B. 5-link developed in the early 80’s for the W201 and W124. This was when the contemporary BMW was still using a semi-trailing arm rear suspension.
I’m not absolutely certain, but I don’t believe it was a semi-trailing arm rear suspension.
You are correct that BMW was still using the semi-trailing arm at that time but I do not think the integral link was derived from a 5-link Mercedes design. There is very little in common between the two designs although I don’t know what the BMW engineers were thinking at the time.
My family has owned three e38s and an e39 M5. BMW was making suspension magic in this time period. The M5 was an astoundingly capable car at speed, stable going fast but not too harsh going slow. The e38 even in long wheelbase form shrinks around you and feels like it wants to be a sports car when you start pushing it. I currently daily drive an e36 M3, regrettably on lowered fiddled with suspension, it is a brilliant driving car. All 3 of theses chassis’s are also extremely easy to drift, a sign of a well balanced setup for sure.
People have lost touch with how great having a big squishy sidewall is for ride and progressiveness of grip. I recently put a set of 75 profile BF Goodrich KO2 tires on my Jeep Comanche, the ride is just fantastic with them, way better than a stiffly spring high rigidity truck should ride.
Agree completely on a nice fat sidewall. I miss the days of 205/70/15 Pirellis.
I do find that my e39 540i drifts with more confidence than any other car I’ve had…
.. when the tires are soaked in coolant from a blown radiator.
The styling of the E39 is my favorite 5 Series. The fact it’s a handling benchmark is even better.
Counterpoint: non-M5 e39 have to understeer from factory and the springs are too soft for non-sport or M5 models. However, it really does nail being pretty good/really good at everything. Real predictable after like 10 miles of driving.
Hottake, that even BMW community will disagree with: The E90 is better.
I don’t think that’s crazy hot take. I had a non-sport package e46 I bought because it was a good deal but always wished I’d held out for the sport package car as the base suspension was just a tad too soft for my liking-BUT I do think the basic fundamentals were all still there and when pushed it got better instead of falling apart like most of the Japanese and american cars do. Sadly I have yet to drive an e90
Most cars understeer from factory…
I meant to type too much*. The front sway bar was weakened after supposedly the lawyers found it a little too tail happy for the average consumer. Which was remedied with the M5 sways.
Um, reducing roll stiffness in the front reduces understeer/increases oversteer.
I have owned an E39 for more than 15 years and have driven almost all variations too. You are oversimplifying things a bit. E39s had at least 3 different suspensions from the factory: regular, sport and M-tech/M5.
Almost every single European E39 came with the sports suspension, which is the holy grail. The regular ones are more comfy but a bit too soft and the M5 is ever so slightly tiring on long trips if the roads are not completely smooth. In the US most base models had the regular suspension and bigger engines or cars with more options were sport. It’s easily seen by how much of a gap is between the rear wheel and the arch at the top because ride height changes.
Factory understeer is a manufacturer’s safe approach to car handling. There is absolutely nothing wrong with that. The magic about an E39 is that you can go from any of those suspension setups and under/oversteer and change between several OEM sway bar thicknesses, springs and shocks to tailor it to your specific tastes. All while staying original. There is probably not any other car in existence that allows you to do that while retaining originality.
Something super important that the article didn’t mention is that inline-6 E39s had a far superior rack-and-pinion and the V8s had a steering box.
It’s pretty common for a BMW chassis to have three plus sway packages. Compared to the E28, e34, and every 3 series till F-chassis, the front end is a bit soft. It’s perfectly fine for a street car, but it’s pretty noticeable when pushed. It’s remedied in the M5 front end, or sport spring plus M5 sway. But still,
Its no e90
I’ve had my ‘03 540 for a similar period (14 years and about 90K miles) and am in agreement, but with one exception: The magic was, for me at least, a very easy spell to break. I recently had the suspension refreshed (new bushings, airbags, dampers and front control arms – my mechanic and I felt the springs were fine) but was unable to find a replacement set of OEM M-sport dampers. The shop recommended Bilstein HDs as a near substitute. They weren’t. After a few hundred miles I’ve decided I need to replace them before they rattle the car apart.
Bilstein HDs are an acquired taste and I also find them too hard. I will stick to Sachs-Boge until they become NLA. At that point I will probably have no other option than to go Bilstein as it became the case with the E34 already (no more OEM option).
The rear suspension on my 2012 Acadia certainly seem similar. Only big difference is separate spring and shock vs. strut (the spring is short and the shock is very outboard, probably for interior width maximization).
Here’s the best pic I could find:
https://i.ebayimg.com/thumbs/images/g/nZ4AAOSwq65kEaBx/s-l640.jpg
The spring goes in the cup at the top and the shock attached to the lower swing arm at the bottom of the picture.
One known issue with the Acadia and its siblings was that some wear in the upper control arms bushings would introduce a wobble at highway speed that felt like a out of balance tire. This wear was not obvious to note until you took out the arm.
It’s become a very popular suspension type since BMW introduced it. Audi, Ford, GM all have a version of it, as do others. My 2015 Mustang has it. The Audi version is a little different because they use a large bushing instead of a link for the small vertical part.
Uh the E39 came out in 1996 which is 27 yrs ago, definitely not over 30 yrs. Don’t know if there are significant differences, but E34 suspension might be close to the same and BTW the E34 handles better than the E39.
The development for the E39 started in 1989, actually!
Sure, but others couldn’t worship it before it came out.
The thing about the SS is that its suspension was developped by the guy(s) who developped the E39 M5’s suspension, and a similar behavior was apparently one of the requirements*. Lucid could have saved money by testing just one of them 🙂
*Dixit Andy Probst and Jason Cammisa, somewhere on Youtube.
The SS?
Well, we’re either talking about Chevy badged Holden’s or Nazis.
Chevy Silverado or Malibu SS?
Yes, the one you mention from the Motortrend article about Lucid and them having an E39 and a Chevy SS.
Somewhere in the Youtube review(s?) of the Chevy SS with Jason Cammisa and Randy Probst there was a discussion about the suspension having been set up by engineers who worked on the E39.
Also, this, from Road & Track (about Holden Australia’s work):
“...Also along for the ride were a handful of eggheads who had helped develop the E39, as well as Holden’s chassis tuner, Peter Hanenberger, a man known for benchmarking the Commodore against—you guessed it—an equivalent 5 Series…”.
I believe there’s some ex-BMW engineers’ involvement in the Kia Stinger’s suspension development, which Stinger happens to be the one usually being compared to the SS (for lack or other models, or because of a real similarity – don’t know).
Ah, yes. When I worked at Lucid, admittedly later on in the Air project, there was never any mention of the Chevy SS. Maybe this benchmark had already been abandoned by then.
The SS is a nice setup… buddies SS handles slightly better than my V1 even though heavier.. benchmarking the E39 is a great idea. BMW bushings didn’t seem to last that long but hey.. do the work and replace them when bad- don’t be lazy and complain about consumables
“ and nothing is so bad that it deserves a rating below five.”
Have you driven a VinFast? I haven’t, but if you believe what some of the reviews have said, it might be the first to qualify.
I had an opportunity to drive one a few weeks ago but then it fell through. You may be right though. Based on what I’ve read and heard, it might be the first one to get below a 5.
> it fell through
The opportunity, or the engine?
I drove a 240sx or some Nissan that the sunroof kept hitting me in the head, and I am under six feet tall, the salesman said that I would get used to it
He works for VinFast now.
Nothing deserved a rating below five because (from the article) : “we weren’t benchmarking the worst cars in the class.”
They can only test and benchmark against so many vehicles, so they pick the class leaders. They ignore the duffers, the ones that would score below five.
It is just a coincidence (I think) that two writers of this site now have E39s. I promise. There’s no point in running up the value of these cars because we’re never going to sell them!
I’m inherently skeptical of arguments that “X old thing has never been / can never be beaten.” Says who? Based on what? In this case, if BMW stumbled onto the holy grail, why wouldn’t they repeat it? Likely, in their case, the needs of the user changed – run flats were seen as necessary, designs evolved to lower profile tires, maybe all-wheel drive options had to be incorporated and changed steering feel, maybe they started selling in new countries that had worse roads and had to change spring / damping rates, etc. Based on BMW’s track record of continued success, I’d bet that they’ve continued to nail the aggregate customer needs successfully, and suspension design just isn’t that big of deal to the end user.
I think the main point being made here was that the E39 remains a benchmark specifically for handling, not overall. Obviously there are compromises needed on handling to support other market expectations over time (weight and runflats being the two obvious ones, I expect)
I felt like this article was the buildup but I was left wondering what the bass drop was. Is there a special name for the E39 suspension or was it a funny take on an existing topology or what?
The rear suspension in the E39 is called an “Integral Link” and it is a unique design different from any other suspension. It uses a small vertical link between the lower arm and the knuckle to control wind-up during braking. The whole design is very compact. The downside is that it doesn’t allow for very much rear steer which is why you see some companies moving away from it.
Yeah, I came in expecting a deep dive with lots of math and diagrams on the intricacies of the E39 suspension.
Not disappointed in the article, I’ll read everything Huibert writes, but I didn’t get what I was expecting.
Thanks for the feedback. At the time, this didn’t feel like the right place for a deep dive into the E39 suspension but that sounds like a great topic for a future post.
I understand qualitative and quantitative analysis, but what I came here for was to understand HOW the e39 is so good, and why it’s a benchmark, but left empty handed.
Is there something special about the suspension? Doubt it.
I have a feeling what made it so good was the wheel size/tires aspect ratio, and overall size of the car.
Today, it’s a smaller car, as everything else has become bloated, and now they put 18s and 19s and 20s on boring old cars, ride quality be damned. They have to do this though, because the bloat of modern cars would look strange and silly with smaller wheels and tires; they’d look like rollerskates.
Agree completely. Huibert is uniquely qualified to tell us “how” BMW did it and “why” they didn’t repeat it in the later cars. Was it just the tires? (This is around the time that BMW went all in on run-flats). Was it a change in the suspension design or the switch to electric power steering?
I suspect it was cost based or packaging
Thanks for the feedback and we’ve updated the post with some more thoughts on that topic.