Stop Watch: Motorcycle Emissions Standards - The Emissions Dance

In a nutshell, the new standards have meant fuel injection and catalytic converters are a must for sportbikes nowadays. EFI has brought benefits to the table in terms of performance and reliability, but catalytic converters have in general meant more weight or less horsepower-or both. An exhaust system that allows the motorcycle to safely meet emissions standards without sacrificing power ends up being big and heavy. Alternatively, a smaller, lighter exhaust is too restrictive and sacrifices power. How have the manufacturers coped with this balancing act? Weight and horsepower numbers have see-sawed quite a bit over the last few years, but few models are both lighter than they were a few years ago and make more horsepower. As an example, look at the stats of the four Japanese literbikes from 2004 to this year. In '04 the average weight of the bikes was 449 pounds; this year (using the weight for the '09 GSX-R1000), the average weight is 460 pounds. The chart at the top of this column shows how average horsepower has changed between '04 and this year as well. On average, horsepower across the rev range is down at least a couple of ponies. Is this really progress?

Horsepower and weight figures aside, there is no doubt that today's sportbikes are better than they were six years ago. Mass centralization means the '10 ZX-10R feels lighter and handles better than the '04 model, even though it weighs 26 pounds more. And the '10 CBR1000RR may make a bit less peak horsepower than our '04 test bike, but it's definitely faster. Given how the basic measures-horsepower and weight-have been impacted by the stringent emissions requirements and add in the always restrictive noise standards that must be conformed to, and it's amazing that the manufacturers have still managed to improve overall performance as much as they have over the last half-decade.

Now to throw a wrench in the works: While the Japanese manufacturers seem to be using heavy exhaust systems and ECU changes to make a U.S.-spec bike, along comes the BMW S 1000 RR, which meets the same strict EPA requirements and sound restrictions the other bikes do, weighs the same as the ZX-10R and yet makes 15 horsepower more. I'm certainly anxious to find out how the company did that, and it will be interesting to see how this shakes things up over the next couple of development cycles for the other four-cylinder literbikes.

One positive outcome of the tiered EPA standards is that 49-state models are now identical to California models with the exception of the charcoal canister. No more different camshafts, ECUs, exhaust pipes and other specific parts that add expense and difficulty for the manufacturers. And as the test procedures and emissions limits here in the U.S. close in on European standards, the manufacturers can produce one model with minor differences for almost any market.

While the EPA has turned its attention to other topics-at least, for now-with no near-term changes planned for on-road motorcycles, things are not over in California. In the past few years, CARB has been working toward tougher evaporative emissions standards for on-road motorcycles, and this recently came to a head with draft regulations proposed. This proposal calls for more restrictive limits concerning onboard refueling vapor recovery-the fumes that escape when you fill your tank. These new limits, which take effect in 2014 and become even more restrictive in '19, will require an elaborate mechanism inside the fuel tank to prevent vapor from escaping during refueling. The Motorcycle Industry Council has objected to the proposal, citing safety issues, additional expense and technical difficulties.

Unfortunately, motorcycles will always be under the microscope when it comes to emissions requirements. Bikes pollute more than the average car, simply because there is no room on a motorcycle for a lot of big, heavy and hot-running emissions control devices. As technology advances and those devices could potentially get smaller and lighter, the EPA and CARB will undoubtedly tighten the standards more, leaving us in a potential stalemate as far as performance goes. On the one hand I'm all for saving the environment, but on the other it's disappointing to see the manufacturers' hard work and progress be offset as it has been over the past few years.

In the meantime, the aftermarket will continue to stand at the ready with exhaust systems, electronic trickery and other performance parts for racers and track-day riders that want their bikes to be all they can be. And now that the EPA's emissions limits have stabilized after those major changes, we are sure to see some real performance gains in the next few years. The BMW may be just a hint of things to come.