Smart cars polluting?
June 28, 2005 10:44 PM   Subscribe

Why would Smart cars not meet US emmissions standards?
posted by Jimbob to Travel & Transportation (12 answers total)
California tests for nitrous oxides, carbon monoxide, and uncombusted hydrocarbon emissions. They all have to be below a certain threshold or else the car cannot get smog certified and cannot legally be driven. You have to get your car "smogged" periodically; this involves putting a sensor in the exhaust pipe and having these things measured.

In addition, the presence of certain design features on cars is mandatory in California, from simple retrofits like positive crankcase ventilation, to things that have to be designed into the car from the very beginning, like oxygen sensors and catalytic convertors. It happens that it's difficult to meet the CA emissions requirements without some of these features, but it doesn't matter because the law requires both the presence of the features and documented vehicle-specific proof that they're working.

Catalytic convertors are particularly problematic with small engines because the reduction in exhaust efficiency robs the engine of horsepower. Basically free flowing exhausts are the ideal condition. Catalytic convertors force the hot exhaust gases through a small-pore platinum mesh. This is good because some of the nasty gases decompose when they touch platinum. But higher exhaust back pressures rob the engine of power and in fact the entire engine has to be designed around this.

I don't know for sure which, if any, of these issues apply to the smart cars particularly; they're just general problems that lots of cars have in getting certified roadworthy in California.
posted by ikkyu2 at 11:27 PM on June 28, 2005

The article said safety and emissions standards. Meeting US safety standards is not a trivial issue and perhaps, on a small car like the smart, that's the biggest holdup. Once a car is 25 years old, I believe, it no longer has to meet the standards. This is why almost no cars newer than 25 years are imported to the US unless they were built to US standards.
posted by 6550 at 11:36 PM on June 28, 2005

6550: Later in the article it makes it sound like emmissions is the problem.

As to safety, I heard from someone (a long time ago) who was trying to buy one that there was a stupid red-tape issue. I can't remember the details but it was some kind of catch-22, where the vehicles _would_ meet US safety standards _if_ they were actually officially tested for them, but they hadn't been tested, and couldn't be tested because they didn't qualify for testing for some reason, something like the testing regs requiring them to be built to handle impact a certain way, while these cars solved the problem by coming at it from another direction.

That was a fair while back though, it sounds like that hurdle may have been overcome now. I probably also have the details a bit mixed up, as I wasn't paying much attention and it was a long time ago.
posted by -harlequin- at 4:11 AM on June 29, 2005

Here's 2 possibilities :

1. They're probably not calibrated for US emissions. It's a significant development effort to do this.

2. Their engine controller may only have European onboard diagnostics software and serial data protocol. The US OBD-2 standard is not trivial to implement.
posted by rfs at 5:38 AM on June 29, 2005

Safety may also be an issue because of the way the standards are written.

Smarts use a pretty unique safety system, described on their website. The car doesn't really have "crumple zones" the way a regular car does (see the photo in the link above). The major deforming element in the event of a crash is the wheel suspension. The frame is a rigid cage, with the passengers insulated from shock by about three airbags each.

It's expensive to go through a full set of crash tests, and US agencies will not accept tests done outside the US. Canada will, in some situations. Safety certification is a high cost issue for an importer into the states. If you only have a few thousand to sell, it may not make a lot of business sense to go through the process.
posted by bonehead at 6:20 AM on June 29, 2005

This other Wired article talks a little bit more about it.
The European version of the car, which is manufactured by Smart, a subsidiary of Mercedes-Benz, is rated to get 60 miles per gallon. However, Campbell said that after being modified by G&K Automotive Conversions to meet the tougher U.S. emissions standards, the car received an initial Environmental Protection Agency rating of just 37 mpg... In its current form, the Smart could be sold in 45 states, but not in California and four others that adhere to the nation's toughest emissions standards.
Also, this article talks about the bigger issue, why the standards would be different:
"In Europe, when people think clean, they focus on global warming and that is carbon dioxide, which is fuel economy," says John Koszewnik, director of diesel engines at Ford Motor Co. "And there, diesels have a 30 to 40 percent advantage. In the U.S., the clean thought is led by California, and there, they're not so worried about global warming. The C02 they produce goes over the mountain. They're worried about NOx."
posted by smackfu at 6:29 AM on June 29, 2005

Well, Canada has let them in, and Ontario has some strict emissions regulations (including having to get the car tested often). It might not be long before they end up in the USA as well.

They're a lot *bigger* in real life, IMHO, than I expected.
posted by shepd at 11:11 AM on June 29, 2005

There are a few U.S. regulations that the Smart Fortwo does not currently meet; even in its Canadian guise. For example, the steering wheel does not lock in place when the keys are removed (Canada also has this regulation, but the Fortwo was given an exemption due to its engine immobilizer).

Another requirement is that the shift pattern and the current gear must be displayed in a single location. On the Fortwo, the current gear is displayed on the dash and the shift pattern is on the stick. Since the stick always returns to a centre position after being tapped forward or back to shift up or down, you can't identify the current gear by simply looking at it. I'm not sure how other cars with Tiptronic-style transmissions get around this.

The 37 mpg rating is puzzling. I recently achieved 66 mpg (3.55 L/100 km) on the highway. Of course, that was with the diesel engine and not the gasoline version tested above, but I was blasting the A/C and driving between 75 and 80 mph (120-130 km/h) for most of the trip.

This issue will be moot soon enough. A third generation Fortwo is due in 2007 and is being designed to meet all U.S. safety and emissions standards. Whether it will be sold in the U.S. is another matter.
posted by Monk at 11:16 AM on June 29, 2005

The low fuel economy may not be so puzzling; diesel vehicles use less fuel than gasoline equivalents—sometimes quite a bit less. No one notices in North America because diesels aren't in general use in cars, save for Volkswagens, but in Europe there are diesel cars that report better fuel mileage than hybrids (though that's really comparing apples and oranges).

In terms of safety, crash tests have shown the Smart ForTwo to be an uncommonly solid car, withstanding impacts that would cause major damage to larger vehicles. Even when facing off against luxury sedans (one crash test involved a head-on collision with a Mercedes S-Class, if I remember correctly) the Smart remains relatively intact, and the passengers sustain only minor injuries. If there is a safety issue in the U.S., it's likely one of certification.
posted by chrominance at 12:31 PM on June 29, 2005

Safety testing is why the 959 was illegal for US road use for the longest time, even the wealth of Bill Gates took years to get the cars approved. Often the problem is bumpers not meeting the US spec which is pretty amazing considering what passes for a bumper on modern US legal cars.

Also European diesel's emission systems require a fuel with very low levels of sulphur. American diesel fuel has very high sulphur levels.
posted by Mitheral at 12:53 PM on June 29, 2005

In Soviet USA, bumpers have to absorb the full impact of a heavy pendulum moving at 5mph without passing any of this impact along to the vehicle frame. For this reason, most US-legal cars have bumpers made of plastic-coated impact foam, which is designed to squash when the regulation pendulum strikes it. The utility of this in the real world is questionable to nil.
posted by ikkyu2 at 4:42 PM on June 29, 2005

I'd thought they'd downgraded the spec to 2.5 mph. I vaguely remember Canada getting different bumpres on some models a while ago because of use retaining the 5 mph rating.
posted by Mitheral at 8:15 AM on June 30, 2005

« Older How do undersea cables terminate?   |   Chapter XIX Newer »
This thread is closed to new comments.