Tips for Reducing Emissions from Older Vehicles
By Jack Shaw
Road transport emissions comprise a significant portion of global air pollution, with older gasoline and diesel-powered vehicles responsible for a considerable share of the pollutants. The obvious solution is to retire these automobiles in favor of newer, more efficient models — or better yet, switch to electric vehicles (EVs) that have zero tailpipe emissions.
However, such a transition might not be feasible for financial or sentimental reasons, at least not quickly and comprehensively enough. In the meantime, these proven strategies can help you mitigate your aging car’s emissions and contribute to a more sustainable future.
1. Repair the Exhaust
Your car’s exhaust releases the gasses the engine’s combustion process produces. It’s the primary gateway for all fossil-fueled vehicular emissions. Over time, wear and tear cause the exhaust system to lose effectiveness. Ensure it’s still up to the task and not missing any critical parts.
Many engines with selective catalytic reduction systems rely on diesel exhaust fluid to minimize pollution. If your car runs on diesel, it will likely have this capacity. Recent tests show these treatments can reduce 95% of nitrogen oxide (NOx) emissions.
2. Get a Vehicle Service
It doesn’t have to be a comprehensive inspection or range of checks. The focus should be on getting an oil change and replacing the filters. Engine oil is vital to the vehicle’s combustion cycles, which impacts emission levels. An older engine running on old oil can produce more hazardous contaminants.
Getting new air filters periodically is also essential to improved emission control. New systems keep dirt out of your car’s engine better, allowing it to run more efficiently and produce cleaner exhaust.
3. Check Your Tire Pressure
Under-inflated tires can increase your old vehicle’s emissions. They carry more surface resistance, which causes the engine to burn more fuel to maintain speed. Check your tire pressure every few weeks, even if you don’t drive the car often. Properly inflated tires also have a longer service life due to less risk of wear and tear while driving.
4. Utilize Fuel Additives
Mixing a fuel additive in your older vehicle’s gas tank can improve the engine’s efficiency and decrease the amount of polluting particulates generated. These special chemicals can help the motor burn off carbon buildup and lessen discharges.
Quality fuel additives can reduce as much as 71% of emissions, including NOx, sulfur and smoke. They can also prevent fuel injector clogging, slowing down the rate of deterioration from extreme temperatures.
5. Avoid Prolonged Idling
Leaving your car running when stuck in traffic or fully parked means your engine is unnecessarily burning fuel and emitting exhaust fumes. This wouldn’t be an issue with newer vehicles, as they’re equipped with start/stop technology to automatically switch off the engine when not in active use. Most older cars lack this function, so you’ll have to do it manually.
6. Drive Safely
The way you drive impacts how much fuel your vehicle consumes, which is directly related to its emissions. For example, driving fast and braking suddenly causes your engine to burn more fuel, resulting in higher amounts of CO2 emitted. Since it’s an older vehicle, you shouldn’t be doing such a thing in the first place. Instead, drive at the posted speed limit to reduce up to 20% of fuel consumption and minimize pollution.
Why Do Older Cars Have Higher Emissions?
Even under increasingly stringent standards, road travel still has the largest carbon footprint. According to the EPA, on-road vehicles — passenger cars, light-duty trucks, buses and trucks — accounted for a combined 80% of the transportation industry’s greenhouse gas emissions in 2022.
Part of the problem lies with the age of the automobiles. Since the enactment of the Clear Air Act of 1970, the EPA has mandated several emission control regulations that affect the engine design and fuel quality of new vehicles. In other words, the older the car, the fewer innovative control systems it has, hence the higher emissions.
Although older vehicles make up a relatively small percentage of the country’s car fleet, limiting their pollution capacity can eliminate a large chunk of the sector’s environmental impact. That’s why several states have implemented scrappage or buy-back programs to encourage owners to willingly stop using their older automobiles.
In California, vehicles made before 2004 represent 19% of registered cars but are the largest emitters of lung-damaging particulate pollutants. The state’s Voluntary Accelerated Vehicle Retirement (VAVR) program incentivizes the timely replacement of older, more polluting vehicles from roadways with cleaner, more sustainable options.
These programs may provide an alternative approach to lowering your car’s emissions. At some point, no amount of reduction strategies will be adequate to minimize pollution rates. If the motor has seen better days, it might be time to retire it and get a modern, more environmentally friendly vehicle.
EVs Are More Accessible Than Ever
The best way to ensure your automobile does not contribute to the industry’s growing carbon footprint is to switch to an EV. Understandably, cost has been a huge barrier to the transition, but the increasing focus on decarbonizing the sector through electrification could improve their affordability.
One promising development is the recently enacted Inflation Reduction Act, which authorizes billions of dollars in investments in accelerating EV infrastructure and adoptions. As more units become available, the market price will decline in line with the economic principle of supply.
The Act also makes provisions for federal and state tax rebates, which can lower the lifetime cost of an EV. The U.S. Department of Treasury estimates people who bought new and pre-owned EVs since January 2024 have saved $600 million collectively, thanks to the assortment of clean vehicle tax credits.
As the industry advances, more incentives will likely emerge, increasing the likelihood of widespread adoption.
Reduce Emissions from Older Vehicles
As cars age, so does their capacity for increased GHG emissions. Curtail your older vehicle’s carbon footprint with these handy tips. Even small, deliberate changes can significantly decrease pollution levels and improve the transportation industry’s sustainability.
Jack Shaw is the senior editor of the men’s lifestyle magazine Modded and has written extensively about electric vehicles, sustainable practices and maintaining a green lifestyle through your everyday actions. His writing can be found in Green Living Journal, Packaging Digest, EcoHotels and more. Connect with him via his LinkedIn.