The Tiresome Truth About SUVs
We all know the trope: SUVs are pointless. To a large degree, this is true. Most people buy SUVs for the illusions that slick marketing campaigns generate: the ability to go anywhere, haul anything, to be independent and resilient and ready for anything, like a conveniently child-friendly automotive Rambo. But the reality is that most SUVs are ready only for a quick trip to the local supermarket if the drizzle isn’t too bad, and for taking the dog to the local vet when there’s a small residential speed bump to be heroically surmounted en route.
Those inspiring video clips of metaphorically hairy-chested SUVs boldly fording streams and tenaciously climbing snowy trails up steep mountainsides are very successful in persuading millions of naïve customers that if they purchase an SUV they’ll be able to perform similar feats, should the morning school run one day become slightly more challenging than usual, perhaps due to someone leaving a crumpled burrito wrapper in the middle of the road.
But are the marketing images a realistic representation of what your typical SUV can accomplish? Can your average SUV do more than haul a few docile bags of groceries from superstore to front door?
Let’s ask a related question: would you be able to fly if you donned a Superman costume and muttered “up, up, and away!”?
Marketing aside, the reality of SUVs is that they’re basically family cars with a higher seating position. Many are only two-wheel drive, and even the all-wheel-drive units have several design features that preclude anything other than gingerly easing the vehicle through a 2 inch puddle.
Ground clearance is one obvious problem: real off-road vehicles need significantly more room between the top of the trail surface and the bottom of the vehicle than is afforded by most SUVs. Without adequate ground clearance, all those delicate parts like exhaust system, fuel tank, suspension components, and drive train all get smashed and can end up being wedged behind or on top of larger-sized pebbles, bringing any forward progress to a literal grinding halt.
Next up is the problem of water. When water enters the air intake system it is rapidly transferred to the engine. Once it gets into the cylinders in any significant quantity (e.g. more than a teaspoonful or two) the engine will hydro-lock. At this point not only is the vehicle not going to move again, it’s also going to require an exorbitantly expensive replacement engine. Your family SUV is highly unlikely to have the air intake placed high enough to permit fording anything more challenging than our aforementioned 2-inch puddle.
But hydro-locking is not the only nuisance caused by a superfluity of fluid. When alternators get wet, they short-circuit. Without current flowing from the alternator there is little to induce the spark plugs to fire (obviously Diesel engines don’t suffer from this problem, which is why submarines are generally Diesel powered*). And if the spark plugs don’t fire, the petrol doesn’t ignite, which means the SUV stops abruptly. Most SUVs have their alternators wherever it was easiest to put them, rather than being located up in the engine bay as high as possible.
Next is approach and departure angles. Unless we’re driving along on a flat road, it may from time to time become necessary to approach things at an incline or even (gasp) a decline. Let’s keep it simple and assume things only go up, in which case we’re concerned about the size of incline we can cope with in our supposedly unstoppable SUV. This means: what’s the maximum angle of inclination at which the forward surface can meet the front tires?
Obviously if we had our tires at the very front of the vehicle, ahead of any other part, this would be a very significant angle indeed. We can imagine perhaps tackling a 45-degree slope, assuming the rear of our hypothetical SUV wouldn’t scrape the ground as it rolled forward to reach the slope in turn. So for real off-road work, a 4x4 needs very limited front and rear overhand so as to maximize the degree of slope it can cope with. Our typical SUV, however, has such low front parts and they are so far ahead of the wheels that its effective approach angle is about the same as a moderately-sized aircraft carrier. In other words, our typical SUV will be defeated by even a curbstone or a more-than-usually-sloping driveway.
All of these are, however, trivial problems when it comes to the biggest issue of all: traction.
Here’s the thing: no matter how sophisticated may be the traction-control system of a vehicle, everything depends on the tires being able to exert grip on whatever surface the vehicle is attempting to traverse. If the tires are slipping, not even the world’s most advanced super-clever electronic aids can do a thing to help. In fact it is always and without exception much better to have a very basic old 4x4 with proper tires than to have a brand new Range Rover with factory-fitted tires. The latter will take you up snowy or sandy mountain trails in perfect security whereas the Solihull Swanker will be skidding and slipping on even a small stretch of flat dewy grass. Assuming it hasn’t already broken down from one of dozens of well-known faults that keep it firmly ensconced at the very bottom of global reliability tables and almost permanently resident at the proud JRL repair shop waiting for yet more replacement parts.
The other problem with SUV tires is that they are increasingly of the low-profile variety. Low-profile tires make a lot of sense on track cars, where we want to minimize side-flex as we screech around sharp corners at 200 kph in a low-slung vehicle designed explicitly for racing use only. On sporty cars like Porches, Lamborghinis, etc. the thumps and bumps they transmit from road to posterior are a way to let the driver imagine that, were s/he more skilled and rather less prone to brown trouser moments, the car could indeed zip around corners with something approaching aplomb. But on SUVs, low-profile tires are like asking someone in a clown costume to run a 100m sprint: totally self-defeating. The smallest sharp pebble or tiny ridge will result in tire damage, and with a torn tire your family SUV won’t be going anywhere — especially with the “space saver” spare the driver probably doesn’t even know how to mount on the rim, even if the toy jack provided were capable of lifting the vehicle safely on an uneven surface, which it’s not.
So why then do SUV manufacturers cripple their supposedly rugged and reliable products with silly tires? Well, because that’s what customers want.
Customers want the illusion of go-anywhere capability but the only places they actually go are on the school run and to the shops. Under these circumstances, off-road tires would be horrid. They’d be too noisy, for a start: all that grip would generate lots of unwanted sound as it stuck to and then unstuck from the tarmac. This would make it difficult to listen to Classic Rock or Baking With Brenda on the expensive sound system (197 speakers and 50,000 watts!!). Proper rubber would also be too expensive: off-road tires are extremely complicated constructions because they have to deal with a wide range of conditions. It’s far, far cheaper to shove some stock car tires on the SUV because no customer is ever going to need anything else. Except when they try to drive in the snow, but then that’s their problem, isn’t it, for not realizing they’ve been duped by false advertising?
Furthermore, customers love big shiny rims. Real off-road tires are big and bulbous and there’s less room for big shiny alloy rims, whereas road tires permit the manufacturers to put on the biggest rims possible. Car buyers are like small children and magpies: they love shiny things. So big shiny rims sell vehicles; practical tires don’t.
All these factors combined make the generic SUV as off-road capable as a geriatric grandmother after someone’s stolen her walking-frame.
SUVs are a fashion, and like all fashions they are both largely pointless and highly profitable for the manufacturers. Back in the 1950s every US automobile was 400 miles long and had tail fins taller than a small skyscraper. In the 1960s every US automobile was adorned with vinyl wood-look exterior panels and vinyl roof coverings that were supposed to give the illusion of a soft-top but just looked as if they had been slapped on to cover up rust (which was probably the case). In the 1980s a great many tedious commutermobiles had spoilers stuck on the back to impart the implausible illusion of potential speed, and in the 1990s SUVs began to shape consumer preferences.
We are now several decades into the SUV phenomenon and it may well persist for many years to come. That high-up driving position combined with some sort of load space in the back makes your typical family SUV an appealing purchase for people who would actually be far better off with a people-carrier like the Honda Odyssey or a Chrysler minivan. Minivans are, sadly, beyond all hope when it comes to appealing to our desire to seem self-sufficient and ready for anything, whereas SUVs enable us to imagine that despite our flabby muscles and our distended bellies and the eight medications we have to take because of our chronically poor lifestyle choices, we could really, truly, if we had to, do something difficult. Or at least, our SUV could do it on our behalf.
If only it had the right tires.
There are, however, a few SUVs that really can get us out of trouble should the need ever arise, because they come factory-equipped with adequate tires. Jeep Trailhawk models come with almost-adequate all-terrain tires and the Jeep Wrangler can be optioned with either the excellent BF Goodrich AT KO2 all-terrain tires or the BF Goodrich MT luggers for use in mud and sand.
The new Ford Bronco likewise can be optioned with very serious all-terrain and mud-terrain tires and the F150 Ford Raptor comes with BFG AT KO2s as standard. Toyota, surprisingly, requires buyers to discard the pointless rubber fitted by the factory and pay out many dollars, pounds, dinero, or rubles for proper tires, as does Mercedes with its now-absurd G-Wagen, which (oh dear, oh dear) comes with big shiny rims and low-profile street tires as per the very embarrassing image above, which is basically Rambo in a tutu.
Land Rover’s new Defender can be optioned with adequate all-terrain tires but as its average distance between failure of some important system is less than 800km, it doesn’t qualify as a serious off-roader. After all, it’s nice to go out into the wilderness but it’s even nicer to be able to come out again, which is something you’re unlikely to accomplish with any JLR product, ever.
The takeaway: if you think you may ever, even once, actually need your SUV for anything remotely approaching terrain more challenging that a nice tarmac surface in near-ideal conditions, the very first thing you should do is pay for some adequate tires. Without the rubber, SUVs are just blubber.
*This is intended to be a humorous comment, honestly…