8/15/2002

in defense of my SUV, part II: safety


Argument 2: Safety :


SUV's don't meet car safety standards, and are really less safe in general, according to Consumer Reports.


When I think of safety ratings, the last place I think of is Consumer Reports. Rather, I think of the National Highway Traffic Safety Administration.

Look at the crash test results for the Ford Explorer, versus the Toyota Corolla.

note that the side imnpact ratings are worse for Corolla. The front impact ratings, according to the NTHSA, cannot be fairly compared across vehicle classes, but side impacts can (as can rollover ratings). The Corolla has only a one-star advantage over the Explorer for rollover, btw, which means about 10% less chance. Not a big deal.

(you can also look at detailed Info on methodology and you can look up any other vehicle )

That's hardly the only source of solid actual data on safety. There is also Insurance Instittute for Highway Safety (http://www.hwysafety.org/), run by the Insurance companies who obviously have an economic need for reliable unbiased data since it affects their business model to the very core.

The IIHS also does crash tests, and again the Ford Explorer compares well to a Toyota Corolla.

Here, the ratings are determined based on anmount of space left after the frontal crash and whether contact was made between passenger/driver's body and pieces of the car (its ingenious, actually, they coat the dummies with paint and then see where the paint marks end up on the interior of the vehicle).

and truthfully this makes intuitive sense. A decent sized SUV has a more powerful engine, giving you speed and control in traffic. It is heavier and has more safety systems, so occupants are protected better. And it has better suspension, brake, and steering components (rack and pinion in fact is standard on the 2002 explorer).

Note that minivans do get consistently higher safety scores in crash tests than SUVs. If all else were equal or if safety was the sole overriding concern, then there's no reason to buy anything other than a minivan. But the data supports the reasonable generalization to say that SUVs are safer for the passengers than a sedan or other car (except for the high-performance puppies like BMW or the Audi quattro models).

Regarding rollovers - the NHTSA ratings already take into account all those manuevrability factors, etc. The ratings are that each star corresponds to 10% less probability. Look at the definitions of the rollover star ratings , and this cautionary note:


even a five-star vehicle has up to a 10 percent risk of rolling over in a single vehicle crash. In fact, because of the aggressive way in which the vehicle is driven and/or the age and skill of the driver, certain five-star vehicles such as sports cars, may have a higher number of rollovers per hundred registered vehicles than certain three-star vehicles, such as mini vans, due to the fact that they are in more single vehicle crashes.


further, the website notes that All Vehicles Can Roll Over -


All types of vehicles can roll over in certain conditions. While SUVs have the highest number of rollovers per 100 crashes (see Figure 4), because of the higher numbers of passenger cars on the road, almost half of all rollovers which occurred in 1999 involved passenger cars (see Figure 5).


Its true that SUVs do have a higher center of gravity, but even passenger cars can roll over. So it doesnt matter what car our hypothetical idiot is driving.

I'm far less likely to get in an accident driving my Jeep, since I have 4WD and I know how to use it. Modern SUVs like the Explorer come with optional electronic brake assist, with standard ABS, and with optional traction control.

Some point to the unsafety of SUVs regarding braking distances. But, braking distances are based solely on weight, meaning that SUVs are no worse than Caddys or Buicks or even minivans as an entire class. And SUVs tend to come with larger pads on their disc brakes to compensate.

But braking is not al about friction, its also about anticipation. With better visibility in my SUV from being higher, I often see brake situations far ahead that the driver of the car ahead of me doesnt. I slow down gradually whereas the car invariably races on ahead and then brakes much harder. If we are talking about an intelligent driver, then the SUV gives you enormous advantages in visibility and control.

Finally, pickups and utility vehicles generally are heavier than cars, so occupant deaths are less likely to occur in multiple-vehicle crashes. Clearly, driving an SUV is safer for me and my family. If you want to drive your family around in a paper-thin econobox, its your choice, though I wont because of the crash test results I linked to above which are clearly not in dispute. but hey, at least you will save ten grand! thats nothing to sneeze at. And econoboxes are great as single-person commuter cars.


Overall, I consider teh data from the NHTSA and IIHs to be authoritative on the subject. Consumer Reports does have "ratings" (ie, "very good" and "poor") which are not quantitative in any way. In fact, CR uses the quantitative data from NHTSA and IIHS as inputs to their subjective and qualitative ratings:


The crash-protection rating in the Consumer Reports Safety Assessments, places more weight on the IIHS's offset tests, which measure how much a vehicle's structure is likely to intrude on the driver in an accident. We believe that the offset crash is a more common type of frontal crash and that the IIHS scores help differentiate one model from another. Unlike NHTSA's frontal-crash test, however, the IIHS's doesn't address how the front passenger might fare in a crash. Safety experts assert that NHTSA's test better gauges a vehicle's restraints. That's why both types of frontal test are critical


next time: gas mileage :)

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