Motorcycles offer a fun mode of transportation, with many believing they are a greener alternative to four-wheelers. Since motorcycles are more fuel-efficient than cars, they should pollute less, right? Well, in reality, motorcycles emit a variety of pollutants that are harmful to both humans and the environment.
Motorcycles can pollute the environment just as much as cars do or even more. The internal-combustion engines of motorcycles are very efficient in converting fuel to energy but produce large amounts of harmful pollutants like hydrocarbons and nitrogen oxides, albeit with lesser CO2 emissions.
In this article, I’ll give you an in-depth look at what pollutants motorcycles emit and the various dangers & health hazards of these pollutants. Moving on, I’ll also share why motorcycles emit so much pollution and compare it to car emissions to see which one is the greener alternative. And finally, I’ll look at what’s currently being done to control motorcycle emissions and what you can do to help.
What Pollutants Do Motorcycles Emit?
Motorcycles have a compact and lightweight form factor, which means their engines don’t need to work as much, leading to better fuel efficiency. And the use of less fuel per mile means less carbon dioxide emission. But on the flip side, motorcycles are notorious for emitting other harmful pollutants into the environment.
Motorcycles emit many pollutants into the air, including hydrocarbons, carbon monoxide, and nitrogen oxides. They also emit carbon dioxide and particulate matter, albeit in less quantity compared to larger & heavier vehicles. All these pollutants are harmful to people & the environment.
For those of you who don’t know, the Environment Protection Agency (EPA) cites oxides of nitrogen (NOx), hydrocarbons, and carbon monoxide (CO) as the most common and harmful pollutants that are front and center of the air pollution challenges we face today.
However, how much of these pollutants do motorcycles emit?
Back in 2011, the MythBusters ran a test to measure how “green” motorcycles were in reference to cars. They compared popular motorcycle models from the 2000s with similarly old four-wheelers.
In their experiment, the motorcycles consumed 28% less fuel and emitted 30% less carbon dioxide. This is because motorcycles are more fuel efficient. As such, they release less carbon dioxide (a known greenhouse gas) per mile traveled, making it not a big worry.
But on the flip side, the two-wheeler produced 416% more hydrocarbons, 3220% more nitrogen oxide, and whooping 8065% more carbon monoxide.
Following this, we have particulate matters (PM) – tiny particles released into the air from tire wear and brake dust. Since motorcycles are smaller than cars with lesser mass, they have a smaller footprint, which leads to lesser PM emissions.
Why Do Motorcycles Pollute So Much?
Both cars and motorcycles use internal-combustion engines (ICE) to generate energy by burning fuel. So why do motorcycles end up releasing more toxic emissions than cars?
Motorcycles pollute more than regular four-wheelers because they don’t have emission control devices like catalytic converters to neutralize the toxic pollutants released from the ICE into less harmful compounds.
These emission control devices are too big and heavy to fit the small footprint of a motorcycle. They can also get extremely hot, which isn’t ideal either. However, passenger cars have plenty of room to accommodate these units, thereby helping to reduce harmful emissions.
Factors Influencing Motorcycle Emissions
Yes, motorcycles release more toxic pollutants into the environment than cars. But that said, not all motorcycles are equally polluting. The emission of two motorcycles can significantly vary from one another based on a number of aspects.
Here’s a look at some of the most important factors that determine how much emission comes out of a motorcycle:
- When was the motorcycle built: The EPA set stricter emissions standards for motorcycles in 2004. Because of this reason, motorcycles built after 2004 have better emission control systems and pollute far less compared to earlier models, especially ones before the ’90s.
- How much the motorcycle has been used: The engine will become less efficient due to gradual wear as your motorcycle covers more mileage. As a result, it’ll start consuming more fuel leading to more emissions.
- 2-stroke vs. 4-stroke engine: Motorcycles running a 2-stroke engine emit significantly more pollutants than a 4-stroke engine. 2-stroke engines use an oil-gasoline mixture and generate more harmful compounds than 4-stroke engines that are gas-only.
- The type of fuel used: Motorcycles that run on gasoline emit fewer pollutants than ones that use diesel. That said, do not fill up your diesel engine with petrol as it can lead to explosions.
- How often the motorcycle gets servicing done: Routine servicing helps to keep the motorcycle’s pipeline clean and the engines well lubricated. As a result, the vehicle will not release as many pollutants into the air.
- Whether the motorcycle has been modified: Many motorcycle owners, especially in the US and Europe, buy motorcycles to identify with the biker persona. As such, they often tend to modify their vehicles for loudness and enhanced performance, which can compromise the emissions control systems.
How Much Do Motorcycles Pollute Compared To Cars
The LA Times published a piece by Susan Carpenter discussing motorcycle emissions. She pointed out that motorcycles only make up 3.6% of total registered vehicles in California and just 1% of total vehicle miles traveled. However, when analyzing the whole passenger vehicle’s smog emissions in California, motorcycles accounted for 10%.
We also see a similar story coming from the MythBusters’ experiment. The show’s host, Adam Savage, even stated, “they’re [motorcycles] far worse” than cars, if not equally as bad in terms of environmental pollution.
Another notable story comes from a team of Swiss researchers. They compared the carbon emission from several motorbikes to regular passenger cars and found the former emitting significantly more NOx.
So, after looking at all these studies and experiments, can we finally conclude that motorcycles cause more pollution than cars?
Well, not so fast!
When we talk about pollution from a vehicle, its emission is only one part of the story. To get the complete picture of its environmental footprint, you need to factor in the pollution emitted in the manufacturing process, during shipping, and so on.
Now, since motorcycles require less raw materials and have a significantly smaller size, their carbon footprint is also lower. Furthermore, motorcycles use many recyclable components, which get a thumbs up from the planeteers.
Also, because motorcycles are more fuel-efficient, they actually release lesser amounts of CO2 per mile traveled than cars.
Considering all aspects and the overall environmental impact, it’s difficult to conclude which vehicle pollutes more – cars or motorcycles. But one thing’s for sure – motorcycles aren’t a “green” alternative to cars.
The Dangers of Motorcycle Pollutants
So motorcycles release a lot of pollutants into the air. But how dangerous and harmful are these to humans and the environment?
Here’s a look at how hydrocarbons, carbon monoxide, and nitrogen oxide harm us and our surroundings:
- Damaging Effects of Hydrocarbons: Hydrocarbons are essentially unburned fuel that can escape through the tailpipe of a motorcycle. These are known contributors to the greenhouse effect, depletion of the ozone layer, and also hamper photosynthesis in plants. In humans and animals, inhaling hydrocarbons will lead to respiratory ailments and even cause cancer.
- Damaging Effects of Carbon Monoxide (CO): Carbon Monoxide is another greenhouse gas (GHG) and a contributor to global warming & climate change. It’s also harmful to living beings as inhaling it reduces the body’s ability to transport oxygen to vital organs such as the heart and the brain.
- Damaging Effects of Nitrogen Oxides (NOx): For humans and animals, certain NOx like nitrogen dioxide (NO2) can cause respiratory irritation leading to chronic lung diseases and even asthma among children. It can also damage the tree leaves and mix with other air pollutants to form ozone, which is much more harmful.
How Can Authorities Control Motorcycle Emissions?
Motorcycles emit alarmingly high levels of air pollutants compared to cars. So what’s being done to control the emission and reduce its impact? Unfortunately, not too much!
Authorities and policymakers can control motorcycle emissions by passing mandates to force manufacturers to build more eco-friendly vehicles. However, there haven’t been any notable advancements in motorcycle emission control technology over the years.
Other than this, it’s also worth considering how motorcycles are used in different parts of the world.
In developed countries, motorcycles are used recreationally by owners to showcase their personality. For example, as per a 2018 survey, around 8% of US households own a motorcycle, and many of them are non-runner vintage models.
As such, authorities don’t pay too much attention to regulating motorcycle emissions and prioritize more serious polluters like construction vehicles, diesel trucks, and the like.
On the flipside, motorcycles tend to be the primary source of transport in developing countries because of their affordability. For example, in Thailand, 87% of households own a bike.
Now, even if the necessary emission control technology was present, passing new emission control mandates means citizens will need to upgrade their motorcycles which is just not financially feasible. Also, restricting motorcycle use will cripple these countries’ transportation systems, affecting too many individuals’ livelihoods.
As such, bringing motorcycle emissions under control is a tough problem to crack and contingent on better technological advancements including policies that provide financial support for mass adoption.
How To Keep Motorcycle Pollution in Check
You as an eco-conscious individual – what can you do to play your part and reduce motorcycle emissions? Glad you asked!
The solution to the motorcycle emission problem is handicapped by our current technologies and can’t be completely controlled. However, we can take steps to reduce the overall pollution and ensure it doesn’t get out of hand.
As a consumer and motorcycle user, there are two practical steps you can take to keep motorcycle pollution in check:
- Buy a new bike, especially if your model was made before the 2000s.
- Properly maintain the motorcycle and make sure it gets routine servicing.
Let’s quickly go over each of these points and see how they can help control motorcycle emissions.
Buy a New Bike – Preferably an E-Bike
Bikes made before the newer, stricter emission control guidelines release more pollutants. Furthermore, older motorcycles with worn-out engines are less fuel-efficient, again leading to greater emissions.
As such, if you own an old motorcycle, especially if it’s before the 2000s, then replace it and buy a new one.
With that said, what motorcycle should you get?
Well, if you absolutely need a gas-powered model, then get a 4-stroker as they release less emission compared to 2-strokers.
However, if you can ditch the smell of gasoline and want the “greenest” solution on the market, then get an electric motorcycle. E-bikes will also save you lots of money in the long run.
Properly Maintain the Motorcycle With Routine Servicing
Properly maintaining your motorcycles by following the manufacturer’s guidelines and making sure it gets routine servicing can all help reduce overall emissions.
Without proper maintenance, the tailpipe can fill up with particulate matter leading to more emissions. Also, the engine will start to wear down, and without proper servicing, it’ll become less efficient, needing to burn more fuel, thereby producing more emissions.
For example, a study conducted by Nepal Air Monitoring and Source Testing Experiment (NaMaSTE) found that emission of PM 2.5, volatile organic compounds, and carbon monoxide greatly reduced following a standard routine servicing.
Other than this, it’s also advised that you do not tamper with the build of your motorcycle. Do not tweak the engine or the exhaust to make it louder or get more performance. The unnecessary tweaking can compromise the emission control measures, leading to the release of more pollutants.
Conclusion
Although motorcycles have more fuel-efficient engines than ICE cars, they produce more harmful air pollutants like carbon monoxide, hydrocarbons, and nitrogen oxides. Because of its small size, a motorcycle can’t equip a standard emission control device to soak up the pollutants.
And since there hasn’t been any major breakthrough in motorcycle emission control, we lack the technology to make bikes more environmentally friendly. Therefore, if you want to stay green but also ride bikes, the best option you have is to buy an electric bike.
