Which is better than Chevrolet’s GMDAT products (such as the Aveo), which have had stars struck off their crash ratings because of actual crash-structure collapse.

Give me lots of airbags, and lots of Styrofoam. Weight is so 1950s.

@Steve Biro
You forgot to mention that Ford endorsed tire pressures on the Explorer that were too low (26psi?). Firestone was subject to arm twisting to agree to the pressures for a better ride. A very unfortunate engineering decision that put the tire on the limit of its load capability at the endorsed pressure. And as you say, many drivers don’t check their pressure.”

Oh, I agree completely. That’s what I meant when I said I’m not letting Ford off the hook here. Not only was the endorsed pressure too low – leaving no room for a lack of maintenance – but clearly the tire spec itself should have been upgraded as the Explorer gained 700-800 pounds over its original version.

But too many people accuse automakers of having faulty designs – particularly in the case of pick-up trucks and truck-based SUVs. They’re not faulty, they’re trucks, not cars. But I’m sure you get my point.

F = A * exp(B*m)

How well does this correlate vs actual crash test results?

In general, larger / more expensive cars have better inherent crash results so those models may very well be coincidental.

For example, 18-25 year old males have the highest accident rates and death rates. If you restricted the Lexus LS430 where it could only be driven by 18-25 year old males, that car would not be Top 10% in driver fatalities per million miles no matter how many safety features it has.…

+1 Cougar Red. Some cars, like Volvo 240’s had low fatalities for their time in part because they were attractive to safety conscious drivers. Fill those 240’s with young guys and the fatality rate would soar. Maybe not as high as it would if you put them in a Prelude, but the driver plays a very big part in these scores. Vettes have high death rates, but when you figure half the driver deaths are not the registered owners, it becomes even more obvious that design can only go so far.

The Smart certainly has decent braking capability (Car and Driver: 167 feet from 70 mph) and the stability control should keep it from spinning, but I’d still prefer to drive a car that can actually take corners.

Brilliant! Lets all drive tanks!

Wait…this doesn’t look so safe: http://www.youtube.com/watch?v=xZWhQDEMH4Y

Define R as the ratio of fatalities between vehicles of two different weights:

R = N1/N2

Modeling and real-world data show that R can be predicted based on the mass of the vehicles:

R = (m2/m1)^2

So, in a collision between a 2500-lb car and a 4000-lb car, there will be 2.8x more fatalities in the lighter car.

This relationship holds true regardless of the direction the accident comes from, or the age or gender of the driver. Those factors, of course, effect the overall accident rate, but not the fatality ratio between two vehicles when they are held constant.

*** Half of two-car crashes in the United States involve cars differing in weight by 20% or more. For weight differences of 20%, the driver of the lighter car is almost 2x more likely to be killed than the driver of the heavier car. ***

The relationship between mass and fatality rates has been measured so repeatedly and accurately, that even a reduction in death rate due to the increases mass of additional passengers has been observed. (i.e. – the driver is safer if they have 3 passengers in the car, due to the additional 450-600 pounds of mass they bring – and the driver of the other car is proportionally less safe).

Fine, you say, so what if we make ALL cars lighter (say to increase overall fuel economy)? That is a solution of limited utility, because when cars of like mass crash into each other, the fatality rate increases as the combined common mass decreases. This has been measured on a US-wide basis, for several individual US states, and using German crash data. Two 2500-lb cars colliding are about twice as likely to produce a fatality as two 4000-lb cars colliding.

What about single car accidents? The big caveat with data here is that a lot of single car accidents aren’t reported. But, notwithstanding that, the data shows that again heavier cars are safer than light cars. The best models of fatality here tend to be along the lines of:

F = A * exp(B*m)

Where A and B are constants selected to make the equation match the data (B has a negative value), F is the fatality rate, and m is the vehicle mass. This graph is relatively linear in the range of masses found in passenger cars, so we can express a simple fatality rate vs mass relationship as follows:

“For every 100 pound reduction in vehicle weight, there is a 4.6% increase in single-car accident fatality rate”

The conclusion is very simple. Heavier cars are safer. Heavier cars are safer in collisions between cars of unequal weight. Heavier cars are safer in collisions between cars of equal weight. Heavier cars are safer in single-vehicle accidents.

For more information see “Traffic Safety” by Leonard Evans, and also the works of Shinar and Vaa.

People can come up with statistics to prove anything. 14% of people know that.

Homer (Simpson)

The Ford Ranger is the “father” of the old Ford Explorer (involved in the handling/tire blowout/rollover problems). The chassis was a major factor in the handling/stability problems. So this report is not surprising. I believe the Mazda pickup on the list is the corporate cousin of the Ford Ranger. An ancient Ford chassis strikes again.”

Oh, come on. The problem with Explorer rollovers had to do with the vehicles gaining 700-800 pounds since their original design with no corresponding upgrade in tire specification, coupled with some manufacturing problems in a particular Bridgestone-Firestone tire factory and a propensity by many Americans to not check their tire pressure.

The “handling/stability” problems, as you put them, occured after an underinflated tire would overheat and loose its tread (but not necessarily the air in the internal carcass). Surprised and incompetent drivers would then overreact, saw away at the steering wheel, lose control of the vehicle and roll over.

I’m not letting Ford off the hook here, but you’re repeating a common mistake by the mainstream media and public at large: oversimplifying and talking about things you clearly don’t understand.

Now, it is true that most pick-ups don’t offer the same level of rollover protection that most passenger cars do. All brands. And anyone expecting a pick-up to handle like a sports sedan deserves whatever they get. Sorry… life is tough. Get over it.

True, but there is no final word. A spreadsheet manipulation of various laboratory crash test results also is far from being the last word. Most of the laboratory type crash tests tell you something about the relative merits of vehicles within a size/weight/type class, but don’t tell as much about how various class vehicles are going to fare in real world crashes.

Also, none of the laboratory tests tell you anything about the many factors which effect the probability of getting into an accident in the first place.

I’m not at all surprised to see small pickups and truck-based sport utilities. In areas where you can get up the speed to really injure yourself eg, not cities), these are the vehicles being driven well past their dynamic limits by kids whose judgement is badly impaired.

I’ve seen three memorable crashes on rural roads (tree, roll, roll) , all of which which were in two-door Blazers driven by teenagers.

They show the Miata as “not too bad” (not great, either), but keep in mind they can only measure registered vehicle-years, not miles driven. Cars that are likely to be owned as 2nd or 3rd cars will look safer than they really are. I have a Miata too (2002), and for what it’s worth my friend lost his 1999 Miata when a midsized sedan turning left on red hit him head-on. Closing speed was estimated at 30mph (they had time for some braking). My friend and his girlfriend walked out without a problem, and both cars were totaled. The Miata has a big front crumple zone and the engine dropped down out of the way.

Side impacts are probably the only type of accident in which the Miata is worse than average (by a lot, unless you have an ‘06+).

the majority of fatalities come from single car accidents where the car hits a tree, or lightpole, or abutment, or wall, or building, etc. and physics teaches us that such accidents are the same as running headon into a vehicle of the same weight and speed, so you don’t gain anything from the extra weight.

That’s a really interesting point. It would be useful to have stats normed for demographics.

I remember back when you could easily get accident and fatality per mile info from the government, and the Miata was better than average. At the time, this was thought to be a demographic phenomenon rather than engineering magic, but I never saw anyone try to prove it.

Source:

http://www.informedforlife.org/demos/FCKeditor/UserFiles/File/DEathRatescombined1994to2004deathorder.pdf

“I’m curious to see the Ranger/B-Series broken down by 2WD vs. 4WD models. I wonder how much of a contributor the higher center of gravity in the 4WD is to rollovers?” I’d guess not much. The 4wd truck does stand a bit taller, but the added weight of the extra driving parts is pretty close to the ground, so that the center of gravity may not be much higher.

Friend of mine had a late-50’s Dodge suburban-type rig, basically a panel truck with rear side windows. This thing was a 4×4 that he’d seen fit to repower with a 392-cubic-inch hemi out of a 57 New Yorker. It was kind of eerie how well that thing handled – we finally decided that it was because the center of gravity wasn’t all that far off the ground.

Take strong braking power (EBD assisted) and a low weight and I’ll stand by my brake & avoid opinion.

Then again, that’s only 120,000 km worth of real world experience.

The top 10 safest vehicles on this list are all mid-size cars with good handling and advanced active safety features:

http://www.thetruthaboutcars.com:8080/2009/04/mostdangerous2009.pdf

I would argue that all ten of the ten safest cars on this list handle significantly better than a Smart.

I would also argue that, as relatively poorly as an Escalade handles, a Smart handles worse than one.

The Smart is a notoriously poor handling, top heavy car. The Smart’s accident avoidance capabilities are just as bad, if not worse, than its accident survival capabilities.