Wednesday, March 30, 2005


Ford Explorer Roof Strength Issues Come To Light

Via Autoprophet comes word that recently-unsealed documents show that the roof of the previous-generation Ford Explorer barely surpassed FMVSS requirements - and violated Ford's own internal standards:

In 1995, the Explorer's strength-to-weight ratio was 1.72. In 1999, the number had fallen to 1.56, just over the federal minimum of 1.5. The slim safety margin concerned company engineers, according to internal e-mails from October 1999 that were unsealed at the trial.

The roof became weaker after the Explorer was redesigned in the 1990s. Ford executives decided each time to put the redesigned SUV on the market even though the roof's strength-to-weight ratio fell below 1.875, the internal safety guideline Ford used for other vehicles, Link said.

To clarify, what's meant here by "strength-to-weight ratio" is the weight that the roof can support, divided by the gross vehicle weight.

There's a few issues here, not all of them Ford's. First, the whole thing with with FMVSS requirements is really getting to me. If the public at large decides that we're going to set vehicle safety standards, then those need to become standards, not suggestions. Either the vehicle meets the requirements or it doesn't, and if it does, I don't see where the manufacturer should be held liable. That's if indeed we think that the feds are best-suited to determine how to engineer a car, and after watching the recent events unfold in Congress, I don't want them anywhere near a CAD tube. So if the OEM does the smart thing and treats those FMVSS regulations as generally inadequate, then the it really needs to hold itself to its own standards.

The next issue is with the spec itself. I'm a sparky, not a mechanical engineer, but even I know that even the most gentle impact force is generally in the neighborhood of 2 G; that is, twice the weight of the object. If the FMVSS spec calls for 1.5, and Ford barely surpassed that, then it shouldn't come as a surprise that roofs collapse.

I fully believe that safety is worth a few hundred dollars per vehicle, and I'd pay for it (and in fact, I have paid for it in the form of some very expensive seatbelts, and an upcoming roll cage, for my Impala SS). And a lot of others will say the same. But when it comes down to actually paying for that safety in the showroom, well... let's just say there's a reason that automakers ignore engineers and make compromises for the sake of saving some money. I'm certainly not comfortable with that reality, and I think it violates engineering ethical standards - consumers are not equipped to understand the nuiances of rollover safety, and thus automakers either need to listen to their engineers or 'fess up to customers that the beancounters are really in charge of keeping everyone safe.

Maybe in the end, we'll get some good third-party verification of rollover safety, much like the frontal offset barrier tests that the IIHS performs (I'm not necessarily a fan of that organization, but I'm unaware of anyone else performing similar work).

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