Dumb Car Questions Thread

[Joey D]

Why are pickups and other utility vehicles body-on-frame instead of unibody?

Towing and load capacity are one of the biggest reasons. A body-on-frame vehicle can haul and tow more than a unibody, although advanced in materials and engineering have made unibodies capable of having high capacities as well. Another is durability, especially over rough terrain. With a unibody, the forces of a twisting vehicle are sent through the entire vehicle. With a body-on-frame vehicle, the body and frame can have more movement and thus puts less strain on everything overall.

It's supposedly cheaper to manufacture a body-on-frame vehicle too and, in theory at least, it's cheaper to repair.

 

[wfooshee]

Noise, vibration and harshness. Not only are they body-on-frame, but the pickup's cargo box is a separate body from the cab, so load issues have less effect on the passenger area.

As for the larger SUVs (as opposed to pickups,) it may be larger GVWR would be available, or at least cheaper, with body-on-frame.

 

[Liquid]

Is my mind playing tricks on me or did Volvo once have a car with one door on one side and two doors on another side? For some reason I am having strong flashbacks to a time where I am positive I saw this car but never got a picture of it.

 

[TexRex]

Is my mind playing tricks on me or did Volvo once have a car with one door on one side and two doors on another side? For some reason I am having strong flashbacks to a time where I am positive I saw this car but never got a picture of it.

The only thing I can think of (mind you I'm far from an expert) is this custom-built "243."

 

[Liquid]

Yes! It was something very much like that but I saw it in a different colour. I also don't think it had the plastic grille on the back window. There must have been more than just one custom job.

 

[TexRex]

Paint and louvers are incidentals. It could have even been the same car before or after a respray, but I gather from the way the cars are put together, and the 2- and 4-door sharing so much including dimensions, it isn't some terribly difficult task provided you can measure, cut, and weld.

 

[Liquid]

louver

I have learnt a new word today, thanks.

 

[Pupik]

I have learnt a new word today, thanks.

Window louvers used to be more common in the 1980s (maybe also in the decade before?) but seemed to disappear as the 1990s dawned.

Was it that tinted windows became legal in more places? Advances in the plastic films? Or just a fad that packed up...and naturally returned somewhat in a less expansive way in recent years?

It actually looked kind of cool on some cars, but I also had weird fashion sense in the 1980s, so make what you will of that opinion.

 

[-Fred-]

Rear louvers are a hot commodity on the GT86/FR-S/BRZ aftermarket for some reason.

 

[Tornado]

And Challengers.

 

[Greycap]

There must have been more than just one custom job.

Perhaps not custom at all.

The rarest production Volvo ever? The 1982 243...

www.swedespeed.com

Having said that, the blue one in the pictures at least doesn't look like a '82 model as it has all the '86 and later facelift features. Then again those are bolt-on retrofits to an older bodyshell and there never was a facelifted 242 to begin with.

 

[Liquid]

Perhaps not custom at all.

The rarest production Volvo ever? The 1982 243...

www.swedespeed.com

Having said that, the blue one in the pictures at least doesn't look like a '82 model as it has all the '86 and later facelift features. Then again those are bolt-on retrofits to an older bodyshell and there never was a facelifted 242 to begin with.

Thanks for the info. The one I saw was indeed a pre-facelift with the older style headlights. It was a beige-ish colour as well, just for the record.

 

[Liquid]

I know American badge engineering is a bit of a complicated mess, especially to us non-USians, but there's one I really don't get:

What's the point of the GMC marque for passenger vehicles?

I understand it for commerical vehicles, heavy-duty ones in particular, but the Silverado/Sierra, Suburban/Yukon, Colorado/Canyon, Express/Savana, Equinox/Terrain just seems pointlessly excessive in a way that only Detroit can master.

 

[INEEDNAWZZZ]

Not being from the U.S, I've always assumed it was just the VW method of offering the same car with varying trim/quality levels under a different name.

 

[TheCracker]

I know American badge engineering is a bit of a complicated mess, especially to us non-USians, but there's one I really don't get:

What's the point of the GMC marque for passenger vehicles?

I understand it for commerical vehicles, heavy-duty ones in particular, but the Silverado/Sierra, Suburban/Yukon, Colorado/Canyon, Express/Savana, Equinox/Terrain just seems pointlessly excessive in a way that only Detroit can master.

It's a bit like Rolls Royce/Bentley and Jaguar/Daimler in the 70's and 80's. Almost exactly the same car, but slightly different fan base. It widens that net for potential customers, or even keeps the attention of a client base whilst they decide what to do with a brand/badge in the future.

With GMC its a bit different as from what i can see, GMC's have always been little more than slightly altered versions of other GM brand vehicles. I think originally GMC was there to target the commercial sector with the other brands there for the man/woman on the street. I guess now there's a cultural identity that comes with the brand, perhaps built up by people who use GMC products through their working life who form some sort of attachment to brand because of it.

 

[wfooshee]

Everything GMC does for passenger vehicles (SUVs and pickups) is a duplicate of the Chevy truck/SUV line. Higher trim and higher price. Some, if not all of the of the SUVs even have a Cadillac version.

Go back a few years, to the 70s and 80s, and you'll see that nearly every car that GM made was offered by every division. Chevrolet, Pontiac, Oldsmobile, Buick, and Cadillac had the same cars, simply different fascias, lights, and trim levels for identification with the division. Look at the mid-80s GM J-body, for example. All 5 US divisions had one, as well as Vauxhall, Opel, Isuzu. How embarrassing must it have been to drive a Cadillac Cimarron, when a Chevy Cavalier was the same car? (Could be why Cadillac could hardly give them away...) Similarly, platforms known as A, C, D, and G were identical and interchangeable underpinnings with slightly different front and rear ends and trim levels to identify the models with the division. Each division kept its own engine lines until the 80s, when divisions began to share engine in the platforms.

Sometime during the Obama years, when GM nearly went under, the Pontiac and Oldsmobile divisions ceased to exist, and the remaining divisions' offerings diverged into more name-specific models. About the same time, Plymouth disappeared from Chrysler's divisions, and Chrysler and Dodge produced their own identities. I don't really even know when Dodge trucks became Ram instead of Dodge...

 

[Liquid]

I know that's what they do but I don't know why with GMC specifically.

 

[Joey D]

I know that's what they do but I don't know why with GMC specifically.

Market share and brand loyalty. For market share, you get far more coverage by offering two slightly different vehicles with the profits rolling up to one entity. Someone might not like the way a Chevy Silverado looks, so instead of removing GM from the equation completely, they have the ability to offer another slightly different-looking vehicle.

For brand loyalty, when it comes to truck some people are fierce with their loyalties. So if they're loyal to GMC they might not ever want a Chevy. There's also this idea that a GMC is what the boss/foreman drives whereas Chevys are what the workers drive. If someone wants to be perceived a different way, they might opt for a different brand on their truck.

GMC made the most sense for GM to do this with since GMC was originally the General Motors Truck Corporation. They already had a precedent for trucks so it made more sense to do it with them than say Pontiac or Oldsmobile.

 

[lilcat89]

I know that's what they do but I don't know why with GMC specifically.

GMC is GM's main marque for commercial fleet sales. That was one of the main reasons that GMC didn't disappear during the Recession.

 

[Neddo]

I've seen many people blame Renault for Nissan's drop in reliability and coolness in 21st century. Why? Every make started making more complex cars and it's expected they are less reliable.

 

[Liquid]

What is the importance of sprung and unsprung weight?

I understand what they are, one is the weight supported by the springs and suspension such as the engine and body and the other isn't such as the wheels and brake discs. But when I browse Wikipedia or other resources about cars, I read random things like moving part x to reduce sprung/unsprung weight. What's the significance of that when the overall package would hypothetically weigh pretty much the same?

 

[Tornado]

Think of it this way: Sprung weight is the entire car planted onto the road loading up the suspension on all four (or however many) tires. Unsprung weight makes it harder for the individual wheels to stay planted on the road whenever they come off it. A heavier wheel/caliper/rotor combo will be pushed further away from the road, harder, than a lighter wheel/caliper/rotor when hitting a bump that affects that individual corner; and thus won't have the original traction for a longer amount of time. It also affects braking performance (lower rotational mass is easier to stop), acceleration (lower rotational mass is easier to start) and steering (feel will generally feel better and be lighter because the steering rack isn't stressed hard). Unsprung weight therefore has a dramatically larger affect on traction (in a "pound for pound" way) than sprung weight; especially traction on less than perfect road surfaces.




Put another way, the less unsprung weight you have, the easier job the suspension has to actually do its job when it needs to.

 

[Exorcet]

What's the significance of that when the overall package would hypothetically weigh pretty much the same?

Just a small comment here, this is one of those cases where weight is used in place of mass and it might contribute to the difficulty of understanding the concepts. The mass is really what matters because it effects inertia, as @Tornado mentioned. A hypothetically massless object (I suppose a wheel/brake package in this case) would not carry inertia or momentum that might fight against the suspension. If something is massless, it requires no force change its velocity or movement, and it can't impart momentum or force on another object to change that object's movement (excluding photons here). Obviously nothing is really massless, but a lighter object comes closer to approximating a massless one.

Ultimately, all the mass (and weight) on the car does matter, but they can interact with different parts of the car in different ways. One of the ways to categorize how different components effect the car is how they interact with the suspension. This is also import in aerodynamics, as downforce (which can be considered as weight) can be sprung or unsprung. Upsprung downforce is much more effective because it's as close as you get to directly increasing tire traction. Sprung downforce is only indirectly increasing traction through applying force to the suspension and can be interfered with by suspension motion or forces themselves.

 

[Pupik]

Do other places pronounce the é in coupé?

American English clearly doesn't; it's not unusual for us to drop accents and diacritical marks (unless they're übercool-looking), but seems weird that we just made it a silent letter.

 

[Liquid]

British English does pronounce it.

Edit:

(unless they're übercool-looking)

Writing the letter and pronouncing it are two different things, clearly.

 

[wfooshee]

Going back to unsprung weight, @Tornado almost said it, but not quite. The actual term unsprung means weight that the springs are not carrying, i.e. wheels and tires, the hub assemblies, and about half of the weight of the suspension arms themselves. Unsprung weight moving around has to be controlled and managed by the springs and dampers, and that's much easier to do with light-weight components. Inboard disc brakes (E-type Jag rear brakes, and rear brakes on most F1 cars in the 70s, and even front brakes on the Lotus 72) are efforts to reduce unsprung weight by moving the brakes onto the car's chassis instead of the hub assembly. Less weight on the bouncy boingy parts means less work for the springs and dampers. That's more of a driver-detectable effect than acceleration or braking is.

And thinking about @Exorcet mentioning unsprung downforce gives me the heebie-jeebies remembering the first F1 wings in '68 and '69 (and the Chaparral 2E in the US,) where the wing's supports were fixed directly to the suspension uprights, and failures had disastrous consequences in F1. The second picture is the car in the first picture, after losing the wing and crashing, colliding with his teammate's car which had already crashed there after losing ITS wing! (Amazingly, the driver, Jochen Rindt, had only minor injuries.)

 

[Liquid]

Where are we with hydrogen-powered cars? Is progress and research being made?

 

[INEEDNAWZZZ]

My ear isn't close to the ground with auto news these days, but I believe Japan is still very much in favour of developing them for their own market, more so than EVs IIRC.

 

[TheCracker]

I think the technology is there or thereabouts but the infrastructure just isn't there to support it and would be incredibly expensive to create it. They struggle as it is to provide enough EV charging points, hydrogen storage is expensive because it has to be kept very cold.

 

[Liquid]

My ear isn't close to the ground with auto news these days, but I believe Japan is still very much in favour of developing them for their own market, more so than EVs IIRC.

Honda was the company I have in my mind who have been doing the most research into it. I probably first heard about hydrogen cars in the early 2010s and the idea that cars could be powered by the most abundant substance in the universe, abundant on earth as well, with far less environmental impact than ICE or even electricity production, that idea absolutely blew my mind.