When a manufacturer designs a car what do they consider its normal theatre of operations?

They consider what the general use of that type of car is. Sedans are for comfy city and highway driving; sports cars are built to handle corners at speed. Pickup trucks for carrying loads over rough roads. Family SUVs and vans for family comfort.

But they also throw in stuff to make it extra attractive, like “sport” accessories for SUVs that never go off a paved road, or tighter handling in a sporty sedan.

For the most part, cars are designed for a certain market, but sometimes the consumers are fickle and aren’t sure about what they want, causing the carmakers to get it wrong. The exception seems to be America where they pull Apple’s trick of trying t tell the consumer what they want and not offering anything else.

To show you how vehicles are tailored to a market, let us look at one of my faves. Subarus calibrate their ABS by testing them out on a frozen lake (or at least they used to) which might explain why Subis have ABS systems that work better in a snowy New England winter than a GM that is designed to seat an overweight person cruising around Southern California.
Of course, Subis are designed for the sort of conditions you will see in Northern climates (snow, ice, twisty roads) and not exactly ideal for an urban jungle. They are designed to drive in the sort of stuff that sends many cars onto the back of a tow truck after spinning into a ditch or getting stuck halfway up a hill. And that is why I love them. They may be heavy with poor MPG, but I never missed a day of work or got stranded away from home due to bad roads when I had my Subi. It was designed for a person like me.

Many American cars are designed for driver comfort first and foremost. Reliability is less of a concern since most people either trade their cars in after three years or are too poor to really be worth caring about. Fuel economy is likewise not a concern since there is infinite cheap oil. Horsepower and passenger space are good for sales so they try to maximize both of those.

Most European cars are designed to handle a wide range of conditions adequately, as Europe is rather diverse. You may see Tuscan sun, or Swedish snow. You may be on the Autobahn, or in a single-lane goat path. Many Japanese cars are similarly designed as many of them are actually sold in Europe. They are also designed for fuel economy since gas overseas runs more than double what it does here.

An American version of a European or Japanese car will have softer suspension (and thus crappy handling; sometimes dangerously so) in order to make the driver and passengers feel like they are sitting in their living room rather than actually moving down the road. They also tend to have wider seats because, quite frankly, we here in the land of Big Macs and deep-fried butter are fat compared to the rest of the world. The modify their existing cars to account for the American market.

As @zenvelo points out, sometimes they throw in useless frills just to attract buyers. And occasionally, the actually offer useful options as well, but that seems rare in today’s “profit at all costs” market.

Some Toyota’s are getting into the “couch on wheels” philosophy. Mushy suspension, crappy tires, poor throttle response (despite having 265 HP!).

Actually I think the previous answers aren’t quite right and that most cars are tested way more extensively than you might think.

There are obviously basic safety standards that have to be adhered to but also bear in mind that most car manufacturers sell to a wide variety of markets and even American car manufacturers have to test for operation in sweltering heat (Texas, Mexico) and freezing cold (Canada) conditions, as well as very rough roads, ice, high altitude running, steep gradients, dust, sand, mud, anything that you might reasonably encounter while driving in the US and Canada at the very least.

Vehicle manufacturers test their cars in a number of “proving grounds” and also indoor test facilities.

There are some details on the proving grounds and test facilities that Ford use to test their cars here: http://en.wikipedia.org/wiki/Ford_Proving_Grounds

There’s an extreme cold weather facility specifically here: http://www.testprofessionals.com/ECW/ and a more general / hot weather proving ground here: http://www.testprofessionals.com/APG/ as examples.

Of course cars are also tailored to the market they’re sold in, but probably more due to what the people want in that particular country than the actual driving conditions. Americans like comfort and convenience with less emphasis on handling and fuel economy, whereas Brits and europeans tend to like fuel economy and better handling because many countries have tight / winding roads and fuel is more expensive.

@WhatEvil Am I to take it that NH does not fall under the category of “reasonable” when it comes to driving conditions?

@jerv New Hampshire? Sorry, you’ll have to be more specific. I’m from the UK so my knowledge on US geography, weather etc. isn’t great.

@WhatEvil Northeastern US, just South of Canada with a small Atlantic coastline, mostly rural, though with some high-speed interstates. Weather ranged from -35F in some winters to 105F during some summers, though 10–95F was a more typical year-round spread. Weather was highly variable; the old saying is, “If you don’t like the weather, wait a minute.”. NH gets the tail-end of hurricanes, blizzards,

I needed a car that could handle 90MPH highway driving, 0.8-lane “goat paths” in the mud (like the road I lived on), sharp corners, steep hills, and occasional standing water a foot deep. Something that would handle 6–8 inches of snow when there wasn’t time to wait for a plow and also handle deep mud (I lived on a dirt road, and we called Spring “Mud Season” for a reason) but something that would not be slow enough to get me killed when driving near Boston where 65MPH is considered a crawl.

My experience is that American vehicles were generally the least able to handle that diversity (they fared poorly in the twisty sections, in tight quarters, and in the wintertime), Hondas and late-model VWs could only handle the maintained, paved roads well (too low to the ground), while older VWs, Subis and Toyotas didn’t even notice the climate or road conditions; they just went, and they always started on the first crank.

@Jerv Well what you described just there would be what I call “European” driving conditions, albeit at the extreme end :)

I would expect most (European) cars to be able to handle the majority of those conditions, but American cars as you said, in many people’s eyes are designed for comfort first and usability second. The difference you noticed between late model and new model VWs may in some part be due to the fact that (as far as I’m aware) production moved to Mexico / South America in the late 80s/early 90s, but I could be wrong, I’m really just theorising here.

It sounds to me like what you really want for conditions like that would be an Audi with Quattro (4WD). I’m not sure about the foot deep standing water, and you’d need snowchains most likely for fresh snow, but they really are great and reliable cars in my experience (my father has been driving them for 30 odd years and doing his own maintenance on them). Alternatively a Land Rover would do all of those things and are largely regarded by many in the auto industry to be the best off roader you can get. The only thing you might struggle with in that regard is the narrow lanes you were talking about, as they’re quite large, but you’d be surprised.

What I will mention that may be of interest to you is that here in the UK (and as far as I’m aware, the rest of Europe) the only American car make that you see with any kind of real regularity is Ford. Other US makes don’t really get a look-in.

Audis are nice if you can afford them. My boss loves his A6, but it’s a little too up-market for my tastes. Then again, they are basically luxury VWs these days. You are somewhat correct there, but my wife and I both had ‘89 Golfs that were night and day; mine was built in the US while hers was built in Mexico at the height of their quality problems that tarnished the VW name for years. Yet both were better than my ‘94 Golf since the 3rd-gen Golf was a few hundred pounds heavier. And our friends ‘02 Jetta almost got swallowed by our road under the same conditions that my ‘89 danced across with grace and poise.

Quite a few people had the old Land Rovers from before they traded bulletproof body panels for leather seats and cupholders. Not great on the highway, but more than capable during the winter.

My weapon of choice when it comes to winter driving that doesn’t cost an arm and a leg remains Subaru, though the ‘87 Corolla comes a strong second due to it’s controllable and predictable handling. BTW, I’ve never used chains even when everyone else around me is, rarely used winter tires, and never been stuck or out-of-control in a non-American car.