Worst (Modern?) Engineering Design Decisions on Automobiles
- Thread starter bremics
- 129 comments
- 12,311 views
- 29,843
- a baby, candy, it's like taking.
- TexRex72
390mm, which is a bit over 15-and-a-quarter. If memory serves, all of the transverse V8 Ferraris (208, 308, 328/GTB, GTS, GT4, Mondial) used the exact same tire, and I believe even a whole bunch of BMWs. But with Ford it wasn't limited to Mustangs, rather the entire Fox line which obviously means your Capri and T-bird/Cougar, as well as Fairmont/LTD/Zephyr. Just way too many dang cars.
So ~1500 tires all told? Pfft...rich people problems.
Danoff
Premium
- 34,011
- Mile High City
While we're complaining about tires, it's pretty difficult to find decent tires to fit a 90s mkII MR2. The car industry has moved to such large diameter rims that tire sizes at the lower diameters are much harder to come by. Very irritating.
I still maintain that runflats are the bane of my existence though. Why have a spare and repair your flat when you could have a tire that will probably need to be replaced completely if you get a puncture? But don't worry, it's more expensive, is louder, has worse ride, wears out faster, and is much much heavier.
I still maintain that runflats are the bane of my existence though. Why have a spare and repair your flat when you could have a tire that will probably need to be replaced completely if you get a puncture? But don't worry, it's more expensive, is louder, has worse ride, wears out faster, and is much much heavier.
- 40,808
I think TRX was intended to be a new standard, rather than just something that only Ford bothered to use in America. A lot of European cars used it since regular radial tires were still garbage at the time.
That it didn't work out that way at all is of little meaning to the people stuck with early Fox bodies paying hundreds of dollars per tire for what are now crappy 80s era tires if they don't want to go through the hassle of changing wheels, certainly; but low profile tires were in at the time and that's what you needed to option to get them unless you wanted a car that rode like an 84 Corvette.
That it didn't work out that way at all is of little meaning to the people stuck with early Fox bodies paying hundreds of dollars per tire for what are now crappy 80s era tires if they don't want to go through the hassle of changing wheels, certainly; but low profile tires were in at the time and that's what you needed to option to get them unless you wanted a car that rode like an 84 Corvette.
Last edited:
- 4,763
- Houston, TX
- 29,843
- a baby, candy, it's like taking.
- TexRex72
Oh, no, my apologies if this wasn't clear, but I was saying give or take 1500 tires...as in they made 300 or so of the LM002s and each has 4 mounted tires plus a spare. Of course that was intended to be tongue-in-cheek because they obviously made extra, but I'm sure it was still a very limited run with the tires needed for only one exclusive [even by Lamborghini standards] vehicle.
- 5,487
- Vic, Australia
- gundalini
When and where did you have lessons? I was taught to use the handbrake at lights (91 in Vic) and promptly never followed the practice once licenced whether in an auto or manual.
- 17,158
- United Kingdom
My 635CSi came with Millimetric TRX's. High performance tyre prices, budget-repaired-re-mould tyre performance
.Still, it was always my aim to keep the car as original as possible, and it meant that power oversteer was easily achievable even with a 3 speed auto and about 200 aging horses.
- 10,824
- Plymouth, UK
- motorforum
Talking of limited tyre options, some cars are hamstrung by the manufacturer.
My Swift has regular tyres, but in a bizarre 195/45/17 size that limits the brands available. I've found branded ones from Falken, Yokohama and Continental. Needless to say, the Falken felt the worst and the Contis felt great - it had Falken on the front, Contis on the rear when I bought it - but it became a bit out of sorts as they wore down. I settled on 4 Yokohama S.drive and they're pretty formidable in the dry. Not too sketchy in the wet, either.
Just wish they had been 205/17s which are more common.
My Swift has regular tyres, but in a bizarre 195/45/17 size that limits the brands available. I've found branded ones from Falken, Yokohama and Continental. Needless to say, the Falken felt the worst and the Contis felt great - it had Falken on the front, Contis on the rear when I bought it - but it became a bit out of sorts as they wore down. I settled on 4 Yokohama S.drive and they're pretty formidable in the dry. Not too sketchy in the wet, either.
Just wish they had been 205/17s which are more common.
- 29,843
- a baby, candy, it's like taking.
- TexRex72
Would it have been that problematic to plus-size regardless of original specification? I know you guys get 100km for our 62mph and your speedo would be off by a more noticeable chunk, but I can't imagine it'd be that bad.
My sister-in-law has a Smart ForTwo and not only does it come with an obscure size, but that size isn't consistent front to rear.
- 4,763
- Houston, TX
- 29,843
- a baby, candy, it's like taking.
- TexRex72
Mannheim Steamroller, that is a big chunk of rubber.
- 2,025
- Azle, Texas, USA
- GTP_KinLM
- KinLM
Not sure if this has been covered..
But cars with “automatic headlights” that don’t also have some sort of auto taillights as well.
I can’t tell you how many times I’ve seen idi- well let’s just call them unaware drivers, driving on the road with their headlights (dimly) illuminated because their car has auto headlights that are always on to some degree, but the rear of their car is COMPLETELY dark without any lights on.
I honestly can’t even blame the driver too much; I’m sure that they see their headlights are on, so they assume they don’t need to ACTUALLY turn them on via the switch.
It’s especially dangerous on black cars at night; might as well be the Invisible Boat-Mobile.
I’ve seen this on a lot of cars, particularly Hondas, for years. The fact that this hasn’t been brought up as a major safety concern at some point for these designers is amazing.
Like, literally, all you have to do is hook up the taillights so they’re always at least dimly lit too, just like the headlights. Why it was deemed that JUST the headlights would be a good idea to have automatically turn on with the car, is beyond me.
ESPECIALLY now, since almost all cars have outside light sensors; surely they could just be programmed to say “hey, it’s super dark out, and the driver of me doesn’t have their headlights on; maybe I’ll turn the taillights on too, just to be safe for other drivers.”
But cars with “automatic headlights” that don’t also have some sort of auto taillights as well.
I can’t tell you how many times I’ve seen idi- well let’s just call them unaware drivers, driving on the road with their headlights (dimly) illuminated because their car has auto headlights that are always on to some degree, but the rear of their car is COMPLETELY dark without any lights on.
I honestly can’t even blame the driver too much; I’m sure that they see their headlights are on, so they assume they don’t need to ACTUALLY turn them on via the switch.
It’s especially dangerous on black cars at night; might as well be the Invisible Boat-Mobile.
I’ve seen this on a lot of cars, particularly Hondas, for years. The fact that this hasn’t been brought up as a major safety concern at some point for these designers is amazing.
Like, literally, all you have to do is hook up the taillights so they’re always at least dimly lit too, just like the headlights. Why it was deemed that JUST the headlights would be a good idea to have automatically turn on with the car, is beyond me.
ESPECIALLY now, since almost all cars have outside light sensors; surely they could just be programmed to say “hey, it’s super dark out, and the driver of me doesn’t have their headlights on; maybe I’ll turn the taillights on too, just to be safe for other drivers.”
FPV MIC
Premium
- 4,308
- Australia
- GT-MIC
I think you may be on to something with it being particularly Honda drivers. Most are elderly here in Australia and probably don't realize there's a difference between Driving lights and Auto lights. https://www.quora.com/Why-would-car...-including-the-tail-lights-to-come-on-as-well
Last edited:
- 40,808
Worse handling, higher price to replace, faster wear, worse fuel economy, significantly worse ride. I couldn't wait to get rid of the ones that were on Ayeka, even though they weren't that old at the time.
Even going up an inch in wheel diameter and going to much more aggressive high performance summer tires lead to an improvement in all of the above.
- 29,826
- Bratvegas
- GTP_Liquid
Fair enough, they never looked like a particularly great design decision but having never been in a car that had them I couldn't have said.
I think as well they only work for a certain type of puncture. If it's a sidewall puncture, which has been the most common type in my experience, then the run-flats won't work.
Danoff
Premium
- 34,011
- Mile High City
They don't work well for any type of puncture. You have no spare, so when you find out your tire went flat, you drive on them until you can get it in to the shop to get it repaired. They're usually rated for about 70 miles of driving on the sidewalls. Problem is, that 70 miles is for the life of the tire. So you get it in to the shop having done 40 miles on it, and shop tells you "ok we can repair it but you've only got 30 miles or so left and so if you get another flat... Better to replace it".
You might be tempted to think that you're no worse off in that situation than with a regular tire. Because it went flat just like a regular tire would, but at least you have the option to drive on it. Wrong. Because if you had a regular tire you'd probably have a spare. And if you have a runflat, you probably wouldn't.
And you might be tempted to think that you're saving the weight of the spare tire. Wrong again! Runflats are hella heavy, and it's unsprung weight.
- 5,974
- Finland
It wouldn't be bad. I went from 205/55R16 to 205/60R16 on my car and the speedo error actually got a lot better, in fact it's gone now. The difference in @VXR's case is 1,5% which is just about guaranteed to be less than the speedo error from the factory.
Now, if the car is designed so stupidly that everything wider or higher than the stock size scrubs at some point, 🤬 out of luck...
Last edited:
- 29,843
- a baby, candy, it's like taking.
- TexRex72
- 27,213
- United Kingdom
Tell me about it. Last three cars I've owned have all had 14" wheels. With the Insight that wasn't such a problem because most tyres that size are rock-hard eco things and obviously that's what the Insight was designed to use. But finding tyres that aren't either a) rock-hard eco things or b) semi-slicks for the MX-5 and the Peugeot has been much trickier.
I've fallen on my feet with each though admittedly. I ran Dunlops on the Mazda (185/60 R14 I think for that), and I've spoken to several people who ran the exact same tyre on other cars and had good words to say about them. They did a couple of trackdays absolutely fine and still had loads of life left when I sold the car.
The Peugeot is wearing Falkens (maybe 175/60 R14 for that one?) and again they seem to work well. Good grip, good feedback, not much noise.
Why? I'm running a GT86 at the moment (basically a Subaru) with it and it seems fine to me. Maybe they break easily or something but it doesn't seem like a bad bit of design.
I'm not sure where this limited-mileage or limited speed thing came from with runflats to be honest. Maybe the very early ones, but a few years back I drove a BMW back from Spain to the UK and got a puncture before I even got into France - a nail sticking into the outside tread. Used the tyre goo, pumped up the tyre back to the correct pressure, and then did 80mph for ten hours up France back to the UK and 70mph for another three hours or so once in the UK...
Maybe it'll only do 70 miles if you're driving on it completely flat for that distance, but with a tyre monitoring system and the fact that most cars without spares have not just the goo but also a compressor on board, and it's much more logical to just stop when the warning light illuminates, fill the tyre with goo, pump it up, and be on your way.
It's no good if you've destroyed a wheel rim on a pothole or something obviously, but then wheels are so big these days that you only ever get a space-saver anyway most of the time, and you're limited to about 50mph for 50 miles on those too, so I'm not sure that's any more beneficial...
- 11,832
- Marin County
I think Danoff is referring to the non-goo type of runflats.
- 27,213
- United Kingdom
Are those even a thing though any more? Maybe early E90 3-series didn't have the goo option (they're among the first cars I remember having runflats more or less across the board) but I can't remember the last time I drove a car without a spare that didn't have a goo canister and just expected you to get by on the sidewalls if you got a puncture.
Incidentally, I don't think ride quality is much of a problem any more with runflats either. I remember speaking to a BMW engineer about it a few years ago and he said they were on about the fourth generation of runflats now (probably even later these days) and they'd figured out how to make them ride properly.
In a modern context of course. Most cars I drive still ride pretty poorly in the greater scheme of things, runflats or not. But I don't think it's solely a runflats problem these days. Mainly just lack of sidewall in general.
- 2,120
- AL
- GTP_Casey
- CaseyP15279
I'm not sure if it does get broken easily on newer models or not but if it does you have to pry open the gas tank door.
Danoff
Premium
- 34,011
- Mile High City
My 2015 Sienna came with non-goo runflats and no compressor. I use proper tires on it (not runflats), and the ride, and noise is much better. Also the tires no longer weigh a ton.
magic_town
Premium
- 956
- Melbourne
- magic_town2
- magilt
Danoff
Premium
- 34,011
- Mile High City
Automatic headlights that do have automatic tail lights are a different problem. My commute used to include a large overpass across a major freeway. It was long enough that the automatic headlights for all the cars would come on before they got out from under it. The tail lights flicking on would cause people to brake, and create a traffic jam there for no reason every day. Years later it probably still does.
