Tag: SUVs

New study finds electric vehicles are driven less than gas cars

A new study from researchers at the George Washington University suggests that emissions savings from electric vehicles (EV) might be overestimated. In one of the largest studies on EV mileage to date, researchers at GW and the National Renewable Energy Laboratory examined odometer data from 12.9 million used cars and 11.9 million used SUVs between 2016 and 2022. They found that battery electric vehicle (BEV) cars were driven almost 4,500 fewer miles annually than gas cars. 

One of the largest studies to date finds the current generation of EV owners drive far fewer miles than owners of gas vehicles, translating to lower emissions savings from EVs.

Peer-Reviewed Publication

GEORGE WASHINGTON UNIVERSITY

WASHINGTON (November 6, 2023) – Mass adoption of electric vehicles (EV) is a key part of plans to decarbonize the United States’ energy system. As EV ownership in the U.S. increases, understanding how much EV owners are driving their cars informs everything from climate and energy models to U.S. policy and energy planning. Thus far, the assumption among modelers and regulatory bodies like the Environmental Protection Agency (EPA) has been that EV owners drive their cars about the same number of miles as owners of gas vehicles. New research published in Joule, however, challenges that assumption and suggests we may be overestimating emissions savings from EVs. 

In one of the largest studies on EV mileage to date, researchers at the George Washington University and the National Renewable Energy Laboratory examined odometer data from 12.9 million used cars and 11.9 million used SUVs between 2016 and 2022. They found that battery electric vehicle (BEV) cars were driven almost 4,500 fewer miles annually than gas cars. The study found a gap for both cars and SUVs: electric cars had traveled 7,165 miles while gas-powered cars had traveled 11,642 miles annually, and electric SUVs traveled 10,587 miles while their gas-powered counterparts traveled 12,945 miles annually. 

“People often assume that buying an EV is good for the environment, and it generally is, but the impacts scale with mileage,” John Helveston, study co-author and Assistant Professor of Engineering Management and Systems Engineering at GW, says. “Our study shows that the current generation of EV owners aren’t using them as much as gas cars. For maximum impact, we need the highest-mileage drivers behind the wheel of EVs rather than low-mileage drivers.” Because EVs generally have lower emissions over their lifetime, replacing a higher-mileage gasoline vehicle with an EV results in larger emissions savings, all else being equal.

The researchers also compared miles traveled in Tesla versus non-Tesla BEVs, given Tesla’s prominence in the EV market and other features like higher-range vehicles and a well-established fast-charging network. Nonetheless, they found that while Teslas were driven more than other EVs, Teslas were still driven less than conventional gas cars. The study did show that plug-in hybrid and hybrid vehicles were driven similarly to gas vehicles, however.

The study has implications for policymakers and regulators who are drafting and implementing emissions regulations, as the findings challenge current assumptions about how far people are driving their electric vehicles. For example, the latest analysis from the EPA assumes EVs are already driven the same number of miles as conventional gas cars. 

“If you’re going to craft a model that predicts how much emissions can be saved from EV adoption, that model heavily depends on how much you think EVs will be driven. If federal agencies are overestimating true mileage, that results in overestimating the emissions savings,” Helveston adds. “We need to better understand not just who is buying EVs, but how they’re driving them. What trips are EV owners substituting for a cleaner trip in an EV, and what trips are EV owners not taking?” 

While not a focus of the study, Helveston suggested a couple of factors that may be affecting how far EV owners are driving their cars, including a lack of charging infrastructure that may limit EV owners’ ability to reliably take longer-distance trips. Researchers also suggest multi-vehicle households may be another reason behind these findings; people who own EVs often own multiple vehicles, and they may be spreading out their annual miles over each of them, resulting in lower overall mileage on the EV.

“The magnitude of data used in this study posed several technical challenges, but I hope our efforts can inform policy around the impacts of EV adoption”, said Lujin Zhao, a GW Ph.D. student who led the study.

The study’s findings also have implications for the electricity grid as it means the anticipated electricity consumption from EV adoption may be lower than utilities are planning for. Additionally, the researchers say it’s also important to consider that making a battery-powered EV typically results in higher upfront emissions compared to making a gasoline vehicle. Helveston and the research team says it will take longer to compensate for those higher up-front emissions if people aren’t driving the EV enough.

The study, “Quantifying Electric Vehicle Mileage in the United States,” was published in Joule. 

-GW-

JOURNAL

Joule

DOI

10.1016/j.joule.2023.09.015 

ARTICLE TITLE

Quantifying Electric Vehicle Mileage in the United States

ARTICLE PUBLICATION DATE

24-Oct-2023

EVs Will Increase Tyre Toxin Pollution

Drivers of electric cars are unwittingly releasing more toxic tyre particles into the air than those driving petrol vehicles, experts have warned.

From NOT A LOT OF PEOPLE KNOW THAT

By Paul Homewood

h/t Paul Kolk

From The Telegraph:

Drivers of electric cars are unwittingly releasing more toxic tyre particles into the air than those driving petrol vehicles, experts have warned.

Scientists, analysts and regulators are growing increasingly concerned about the amount of potentially harmful tiny particles coming off tyres, especially those from heavier cars such as electric vehicles, due to the number of toxic petrochemicals that they are made from.

This comes as the Government is attempting to reduce carbon emissions under its “net zero” drive by encoruaging drivers to use electric cars. Motorists with older petrol vehicles in London also face fresh charges to enter Sadiq Khan’s Ultra-low emission zone (Ulez), which is expanding to cover all London boroughs from August.

Ministers have also been considering a “tyre tax” to cut harmful emissions.

However, experts have warned that non-exhaust pollution will rise when more electric cars are on the road.

Professor Roy M. Harrison, at the School of Geography, Earth & Environmental Sciences at the University of Birmingham, said: “The non-exhaust emissions from road traffic in developed countries now exceed the exhaust emissions, so that is a problem. And it’s a problem that will get slightly worse as we go into a battery electric fleet and also as traffic volumes probably increase additionally.”

Modern tyres contain around 400 organic compounds, many of which are derived from crude oil. Some of these are highly toxic chemicals such as naphthalene, toluene, and isoprene, as well as heavy metals like zinc and lead.

Every time someone drives, tiny bits of their tyres break away, releasing a range of these toxic chemicals, both in larger pieces and nanoparticles. The bigger pieces will be carried off the road by rain into rivers and sewage, where they may seep into the earth or flow into the sea. The smaller particles will filter into the air and be breathed in by humans and animals, reaching deep into the lungs.

Nick Molden, chief executive at Emissions Analytics, which studies the pollution caused by tyres, said: “We’re going diametrically in the wrong direction at the moment by making our vehicles heavier.

“SUVs and electric cars are shedding an awful lot of tiny but nasty chemicals – some of which are highly carcinogenic – which we’re partly inhaling but are also getting into our water and food.”

Emissions Analytics conducted a test last year that concluded almost 2,000 times more particle pollution is produced by tyre wear than what is pumped out of the exhausts of modern cars.

“If you’re worried about burning fossil fuels in your car engine, you should be as worried about the wear from tyres”, Molden said. “Tailpipe emissions really only affect the air, whereas tyre wear affects air, soil and water.”

This is an issue for the UK and other nations as they move towards having more electric cars. The heavier a vehicle, the greater wear a tyre will face. Electric vehicles weigh an average of 200kg to 300kg more than a petrol car, due to the battery pack. They also need higher torque – the twisting power that launches a car from a standing start – than internal combustion engines, which also puts more pressure on the tyres.

The tyre manufacturer Michelin said conventional tyres wear out around 20pc faster in an electric vehicle, while Goodyear said they can wear out as much as 50pc faster.

In February, researchers at Imperial College London called for more research into the potentially harmful impact of toxic tyre particles on health and the environment. It said six million tonnes of tyre wear particles are released globally each year, and in London alone, 2.6 million vehicles emit around nine thousand tonnes of tyre wear particles annually.

The weight of electric vehicles is already causing concern from some engineers that they will put some multi-storey car parks built in the 1960s and 70s under such pressure they will be at the risk of collapse, The Telegraph reported in April. Government ministers have also urged councils to check how much weight bridges in their area can hold.

This may become even more of an issue in the future as electric cars are set to carry more weight. Rather than battery packs getting lighter as technology advances, electric car manufacturers like Tesla are actually opting for heavier iron-based batteries that do not use the expensive, scarce materials of nickel and cobalt.

https://www.telegraph.co.uk/money/consumer-affairs/heavy-electric-cars-toxic-tyre-particles-petrol-vehicles/

I’m sure a tyre tax will solve the problem!!

We have known about the greater tyre wear on EVs for years, with its implications for particulate matter pollution. But the issue of toxic chemicals is now an added problem.

Interestingly, Michelin comment that tyre wear could be 20% higher. Tyre replacement for my car is the biggest maintenance cost for me, so along with extra brake pad wear the claim that EVs are cheaper to maintain sounds like hogwash.