Cars can sometimes seem to work almost through black magic. Sure, most of us know that engines largely work through the principles of “suck, squeeze, bang, blow” and missing one of those can cause a no start condition. Still, you can run into some weird engineering that just makes you go “huh.” What’s a piece of car engineering that makes you scratch your head?
Most of my cars are of the German variety, so I get to sit there and think about odd engineering decisions all of the time. Sadly, I rarely get an answer to what I’m confused about, but maybe I can expose you to the same things rattling around my head.
Let’s take a look at a 2008-2015 Smart Fortwo as an example.
Smart Fortwos with the standard transparent roof get a giant roof panel made out of polycarbonate from Webasto and Bayer Material Science. When the second-generation Fortwo made its European release in 2007, this roof was a huge deal. The previous Fortwo had a glass roof that was prone to shattering, but this new panel, spanning 1.2 square meters, was then the largest polycarbonate panel put into production.
The Makrolon AG2677-branded panel was pitched as better than glass. It didn’t shatter from rocks, weighed a fraction of glass, and maintained amazing clarity. The problem was that somehow, these panels began cracking from the inside out (a process known as crazing) often as early as just 6 months in. In theory, the panel should have been able to stand up to the abuse. They had UV coatings and data sheets suggested the panel wouldn’t start to break down until around 291 degrees.
Yet, these roofs began cracking and delaminating left and right only months in. Webasto tried reformulating the polycarbonate, which made the roofs last from a handful of months to a few years, but they still failed, anyway. It’s been so many years since I last saw a Smart 451 without a damaged roof that I’m sure the only undamaged 451 roofs out there are attached to low-mile garage queens. It’s such a common problem that I had no issue finding a Smart for sale with a failing roof:
That’s just one example of strange engineering. I could prattle on all day about how my Volkswagen Phaeton’s HVAC blower motor is dead and for some reason only Volkswagen can explain, I have to remove the windshield wipers to replace it.
Stephen Walter Gossin has his own example. Remember that expensive, yet somewhat rusty Toyota Camry that Thomas wrote about? Gossin noticed how the exhaust is pretty goofy:
Yep, there’s a U-turn in there to connect to a catalytic converter. Gossin says:
Is it just me, or would placing the exhaust flex pipe further aft negate the need for that U-turn off the cat-converter? So weird!
His other thoughts:
Possible logic #1: The only logic I can think of is having an equal length of exhaust tubing from the ends of each exhaust manifold to the flex pipe, but even that seems like a straaatch to add that extra metal/material/cost and weight.
Possible logic #2 (yes, I’m still a-head-scratchin’): Maybe moving the flex pipe aft creates too much fore exhaust system weight and thus, too much pressure on the flex pipe. Still unclear and confusing either way.
I don’t have the answer to that question, but maybe you do. Also, what other examples of weird engineering have you found out there? And to make this a little harder, the existence of the Tesla Cybertruck is too easy.
Hands down BMW’s “accessory belt ingested in engine” beauty.
Gracefuly offered to us by BMW in the N54, N55, and probably others.
The engineering:
Oil filter housing (above accessory belt) always leaks. That’s fine.Hoses from Oil filter housing to oil cooler also can leak. That’s fine.Said oil drips straight on the accessory belt. That’s fine.Accessory belt eventually slips of its pulleys or breaks up from the oil. That’s fine.Amazingly enough, once it falls off, the belt has no space to go forward (towards the radiator). It wraps around the crankshaft pulley and then behind it, getting ingested through the main crankshaft seal and inside the engine.As an added bonus, on Xi (awd) models – removing the engine oil pan requires dropping – among other things – the shafts, as they go through their own tunnel throught the engine oil pan. And removing it is necessary to clean up the mess.
….having to undo motor mounts & tilt the motor forward to replace the 3 rear spark plugs on a Buick century limited seemed to be a bit of an engineering ask, in my humble..
Reminds me of my time at Mercedes in the 90s. The V12 models had the oil filter housing between the engine block and a frame rail which was no problem on newer cars. Unfortunately the motor mounts would inevitably collapse and now there isn’t enough room to get that filter housing cap off. I still have the big prybar I bought specifically for that job…
Pretty much everything about the engine installation in a classic Saab 900. Let’s bolt the engine to the TOP of the transmission such that the top of the transmission is the oil pan. Then to get the drive down there, we will use a big-azz chain AFTER the clutch assembly to maximize the inertial of the transmission input shaft so as to make shifting as terrible as possible. And let’s take that transmission that was originally designed for an 80hp motor we bought in from Triumph and bolt it under a turbo-charged 16V with up to 185hp (and a lot more if you up the boost) while only really marginally strengthening it over the years – we always gave money to the engine guys first and the transmission guys second. And put the whole mess in the car backwards such that the accessory drivebelts are against the firewall, meaning that changing a clutch is quicker and easier than changing the belts or alternator or waterpump. Oh, and for the early cars, we will keep the Triumph motor’s goofy shaft driven water pump that needs special tools to deal with. They did fix THAT eventually. And for those not inclined to shift for themselves, lets use an antediluvian 3spd non-lockup sludgepump of a Borg-Warner automatic from 1969 to the end of C900 production in 1993. because nothing else will fit with our whacky design.
I love them, but Saab engineering was at right-angles to the rest of autodom until they hooked up with first Fiat (to co-design the 9000/Chroma/Thema/164) and then GM bought them.
2011 Grand Cherokee, 5.7L 4wd. To change the starter, the official method involves dropping the K frame and transfer case. IF they would’ve put it on the other side of the transmission it would’ve been right in the open… My method involved NOT dropping the K frame or transfer case and just scraping the bejesus out of my forearms and hands.
Oh, come on. Working on Mercedes – especially the R107s I love – have taught me that sometimes, all you can do is carefully put down the wrench, back away, shake your head, and say “Germans. Go fig.”
My favorite bewildering German car engineering complication is almost imperceptible delay built into things like headlight switches on more modern, CAN-BUS driven cars. My theory is that it is like that to convey a sense of premium complication. A simple relay is just an instantaneous click, but with CAN-BUS, the car receives your request to turn the lights on, it ponders your request for a milisecond, then it turns the lights on.
My least favorite result of this is the throttle response in my N52. VANOS controls everything, and has a VERY perceptible lag coming from a “normal” car.
First car bought in 1981 at age 17 for $300 a 1969 Pontiac Le Mans 2 door hardtop, perfect interior/rusty body, and with 3 regular tires and one snow tire that howled so loudly, you could tell when I was coming down the street!, and Mini Moon disc hubcaps, with the Pontiac 2barrel 350 V8, it had the engine timing go off when the ‘nylon’ teeth on the upper timing chain sprocket wore down enough to let the chain slip. Fortunately a new sprocket ⚙️ replacement fixed it with no other damage to the engine.
The dashboard in 1969 was a beautiful looking padded surface that included the instrument cluster covered by the dashboard padding. Getting to the speedometer or clock or fuel gauge pods, as I did wanting to see if I could fix the non operable clock required going behind the dashboard. This meant removing the full width lower dash air conditioning ductwork with the two ‘crotch cooler vents’, while this ductwork did seal the lower dash up from firewall noise, no access behind the dashboard if not removed. Then reaching up around the steering column to try to locate and loosen the mounting screws? Bolts? Can’t exactly recall, but made it interesting. This was to be a one year only dashboard design as the 1968 Le Mans dashboard has a front faced removable panel around the instrument cluster and the 1970 Le Mans reverted back to this design through 1972. I’m sure the dealership mechanics who wished to upgrade the gauge clusters, (full gauges versus just fuel gauge/rest idiot lights, adding clock or tachometer) at a customer request raised holy hell about it.
Ford 6.4L Powerstrokes have so much crap packed in under the hood that mundane jobs require removal of the truck’s cab. That’s soviet nuclear power plant level questionable engineering.
Sounds more like German engineering to me.
Germans never engineer anything unless they overengineer it.
This was my introduction to German over engeneering:
https://cdn-0.barnfinds.com/wp-content/uploads/2021/01/1981-Porsche-924-Turbo-Engine.jpg
That’s a 2.0l 4cyl in there!
My big bro has sold his because of how many times the cab has had to come off and he’s tired of paying for it. Under what system are the people who engineered that able to even have jobs…
Always wondered how they did this on the RV and ambulance models that were on the f350 chassis not the van
On a Leyland P76 (a fairly conventional 1970s RWD large sedan ) replacing the heater core requIres removing the entire HVAC assembly from the car. Rather than sitting behind the firewall, it incorporates part of the firewall into the assembly, with a series of fasteners all the way around a flange that overlaps the rest of the firewall – on the engine bay side! So instead of crawling under the dash and unbolting a lot of stuff then pulling it out through the interior, you have to first remove THE ENTIRE ENGINE/GEARBOX ASSEMBLY and pull the HVAC assembly out through the engine bay!
Here’s one I remember from the late 1990s-Chrysler Corporation’s “Cloud Cars”
(Dodge Stratus sedan/Chrysler Cirrus/Plymouth Breeze and Chrysler Sebring convertible). remember the commercial spoken by the late Edward Hermann, where he stated:
“ Can we enhance performance by moving the battery?”. Which, of course Chrysler did, however, if that battery went dead the only way to get the old one out was to put the car on a lift and remove the driver side front tire,wheel well shroud remove the battery from the driver side front wheel well.
Naturally, installation was the reverse of removal!
I had a Chrysler LHS with the same uh “design choice”, except on the passenger side. Battery died, I figured out where the battery was, got the wheel off, got the panel open, took one look at the roughly half-inch of clearance between the battery posts and the body, and called AAA. It’s not just that the battery was in an insane spot, it’s that you were basically playing “operation” getting it in and out. I can wrench, but I drink too much coffee to attempt to maneuver a metal wrench through that little space.