Fuel Efficiency Has Improved 35.4% in the Past 20 Years — Here Are the Models That Have Advanced the Most

Electric cars are a hot topic in the quest to improve our carbon footprints, but gas-powered vehicles have made their own strides. In fact, vehicles have become significantly more fuel-efficient in the past 20 years, which can translate to lower gas expenses for consumers.

This study looked at fuel efficiency and carbon dioxide emissions across vehicle model years. Additionally, if you’re looking to upgrade to a more fuel-efficient car, stick around for tips on making the switch — including whether an auto loan may be right for you.

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Key findings

• Over the past 20 years, vehicles have become significantly more fuel-efficient. The fuel efficiency for new 2022 models is estimated to be 26.4 mpg, according to preliminary Environmental Protection Agency (EPA) data — up 35.4% from 19.5 mpg across 2002 models. Cars from those same model years have seen an even greater 46.1% increase in fuel efficiency, rising from 22.8 mpg in 2002 to 33.3 mpg (preliminary) in 2022. Meanwhile, truck fuel efficiency has risen 41.8% from 16.5 mpg with 2002 model-year vehicles to 23.4 mpg with 2022 (preliminary) model-year vehicles.
• Nissan, Kia and Toyota have improved the fuel efficiency of their vehicles the most. The average mpg on Nissan’s 2022 models is 39.4% better than the mpg on its 2002 models. Following that, Kia has increased fuel efficiency by 38.7% and Toyota by 34.3% over the past 20 years.
• Improved fuel efficiency in vehicles leads to reduced annual gas expenses. According to the Federal Highway Administration (FHWA), the average number of miles driven per year is 13,476. If you had driven that distance with a 1982 model, you would have spent $2,524 in inflation-adjusted dollars on gasoline. However, if you use a newer model from 2022 with last year’s average gas price of $4.09 a gallon, you would only spend $2,090 — 17.2% less.
• Generally, though, consumers aren’t driving newer cars. On average, cars and light trucks on the road in 2023 are 12.5 years old. If you compare the fuel efficiency of a 2010 model (based on the 12.5 figure) to that of a 2022 model, the latter will be 16.8% more fuel-efficient. Based on 2022 gas prices, driving the average number of miles in a 2010 car model would cost an additional $351.40 annually.
• New vehicles not only have a higher mileage per gallon, but their carbon dioxide (CO2) emissions have also decreased. From 2002 models to 2022 models, vehicle emissions have decreased by 27.6%, with cars seeing a 34.3% drop and trucks experiencing a 30.3% dip. During this period, Kia, Nissan and Toyota vehicles showed the greatest drop in carbon dioxide emissions, at 29.1%, 28.5% and 25.7%, respectively.

Fuel efficiency has increased 35.4% in the past 20 years

Vehicles are becoming more fuel-efficient — and the increase is significant. According to preliminary Environmental Protection Agency (EPA) data, the fuel efficiency for new 2022 models is estimated to be 26.4 mpg. Meanwhile, the fuel efficiency for 2002 models was 19.5 mpg — equaling an improvement of 35.4%.

Breaking that down even further, cars from those same model years have increased fuel efficiency by 46.1% from 22.8 mpg in 2002 to 33.3 mpg (preliminary) in 2022. Meanwhile, trucks have seen a slightly lower 41.8% increase in fuel efficiency, rising from 16.5 mpg among 2002 model-year vehicles to 23.4 mpg among 2022 (preliminary) model-year vehicles.

Several factors may play a role in the rise in fuel efficiency. Over the past 20 years, engine, transmission and hybrid technologies have improved significantly, with individual technologies (like stop-start and regenerative braking) increasing fuel efficiency by as much as 35%, according to the U.S. Department of Energy. As technology improves, consumers’ demand for fuel-efficient vehicles has grown, too. In fact, a 2021 survey from Consumer Reports found that 89% of Americans believed automakers should continue improving fuel economy.

It’s not just consumer demand, though — improving fuel efficiency is largely a requirement. Corporate Average Fuel Economy (CAFE) standards, which were initially set by the National Highway Traffic Safety Administration (NHTSA) after the 1974 and 1980 oil price shocks, were amended after another oil price shock in 2008 — greatly pushing automakers to improve fuel efficiency across their vehicle fleets. Between 2008 and 2022, CAFE requirements on passenger cars increased from 27.5 to 48.2 mpg. Looking forward, 2025 model passenger cars must have a minimum fuel efficiency of 55.3 mpg.

Fuel efficiency by model year, 2002 to 2022

Source: LendingTree analysis of Environmental Protection Agency (EPA) data. Note: 2022 data is preliminary.

Looking back even further, fuel efficiency has been on the rise for a while. From 1975 to 2022, fuel efficiency across all vehicles has increased 101.5% from 13.1 to 26.4 mpg. Cars have seen an even greater 146.7% improvement in fuel efficiency in that time frame, rising from 13.5 to 33.3 mpg. Similarly, fuel efficiency among trucks has increased 101.7% from 11.6 to 23.4 mpg.

Nissan has improved fuel efficiency the most — here are the makes that follow

While all vehicles have seen increased fuel efficiency, some automakers have done a better job than others. Although the EPA doesn’t provide data across all vehicle makes, Nissan ranks highest among those analyzed. Between 2002 and 2022, the fuel efficiency in Nissan models has risen 39.4% from 20.1 to 28.0 mpg.

Following that, fuel efficiency among Kia vehicles has increased by 38.7% from 20.7 to 28.7 mpg, and fuel efficiency has increased by 34.3% among Toyotas, from 20.9 to 28.0 mpg.

Vehicle makes that have improved fuel efficiency the most

Source: LendingTree analysis of EPA data. Note: 2022 data is preliminary.

Both Nissan and Toyota have played a role in technological innovation. Nissan has focused on improving continuously variable transmission (CVT) efficiency — which lowers fuel consumption by improving gear-changing — along with reducing the weight of its vehicles. Nissan introduced several electric systems across its vehicle makes, including regenerative braking. Meanwhile, Toyota developed engines with improved thermal efficiency.

Toyota has been a leader in hybrid vehicle technology, with models like the Prius — one of the earliest consumer hybrids — massively improving fuel efficiency. Kia also introduced hybrid options to its lineup.

Improved fuel efficiency reduces annual gas expenses

Overall, driving a fuel-efficient car reduces annual gas expenses — though that varies by model year. According to the Federal Highway Administration (FHWA), the average number of miles driven per year is 13,476. In a 1982 model, you would have spent an average of $2,524 in inflation-adjusted dollars on gasoline over a year. Using a 2022 model car with last year’s average gas price of $4.09 a gallon, though, you would only spend $2,090 — 17.2% less.

According to LendingTree chief credit analyst Matt Schulz, that could make a significant difference for consumers.

“We’d all be happy to have an extra $435 a year in our pockets,” he says. “It may not change lives, but that extra $35 or so savings per month would give the average household a little more wiggle room in their budget. That could allow them to put a little extra into savings, pay a little more toward their credit card debt or dedicate a little bit extra to their other financial priorities.”

Annual gas expenses by year based on average annual mileage

Source: LendingTree analysis of EPA, Federal Highway Administration (FHWA), Bureau of Labor Statistics (BLS) and AAA data. Note: 2022 data is preliminary.

Saving that much isn’t always the case, though — some model years save significantly more than others. For example, driving a 2002 model car would have cost 37.0% less than driving a 2022 model car. Meanwhile, driving a 2012 model would have cost 21.0% more. That’s largely due to changes in gas prices over time.

Consumers are driving older cars — and may be missing out on fuel savings

While newer, more fuel-efficient cars may translate to more savings, consumers generally drive older cars — meaning they may be missing out.

Cars and light trucks on the road in 2022 are 12.5 years old, on average, according to S&P Global. That means we’ll look here at cars manufactured in 2010. While a 2010 model has a fuel efficiency of 22.6 mpg, a 2022 model has an estimated fuel efficiency of 26.4 mpg — meaning the newer model would be 16.8% more fuel-efficient.

Differences in fuel expenses between a 2010 and 2022 model vehicle

Source: LendingTree analysis of EPA, FHWA, BLS and AAA data. Notes: 2022 data is preliminary. Values were rounded for display, so the difference may appear slightly off in some cases.

Based on average gas prices in 2022, driving the average number of miles in a 2010 model would cost an additional $351.40 annually. But because some age groups may drive more than others, that average varies. Consumers ages 35 to 54 could save $398.70 — the most of any age group — while consumers between 16 and 19 could save $198.80 — the least.

Those savings may be significant depending on your age, but Schulz says you shouldn’t jump the gun on a car purchase just to lower your fuel expenses.

“Fuel efficiency is certainly worth considering when deciding whether to buy a car, but it’s hardly the only cost,” he says. “There are likely significant differences in overall sticker price, interest rate and even insurance costs. Ultimately, a vehicle is one of the biggest purchases we make, so it isn’t to be entered into lightly. It’s important to take your time, do your homework and understand what matters most to you when it comes to that vehicle.”

Carbon dioxide levels have also decreased

Fuel efficiency isn’t the only improvement in vehicles — carbon dioxide levels have also decreased. Vehicle emissions have decreased by 27.6% overall between 2002 and 2022 models, with cars seeing a 34.3% drop and trucks experiencing a 30.3% dip in that period.

Fuel efficiency and emissions are directly related: As vehicles have become more fuel-efficient, they produce fewer emissions per mile driven. Additionally, the EPA and the NHTSA have established regulations for greenhouse gas emissions and fuel economy standards for passenger cars and trucks, pushing automakers to develop cleaner vehicles.

How might this impact consumers? Vehicles with lower emissions are generally more fuel-efficient, which means they consume less fuel per mile driven — and it may lower fuel expenses.

CO2 emissions by year, 2002 to 2022

Source: LendingTree analysis of EPA data. Notes: 2022 data is preliminary. This is measured in grams of CO2 per mile.

During this period, Kia reduced its vehicles’ emissions the most, with its 2022 models producing 29.1% less carbon dioxide emissions than its 2002 models. That’s followed by Nissan (28.5%) and Toyota (25.7%).

Manufacturers with the biggest decreases in carbon dioxide emissions, 2002 to 2022

Source: LendingTree analysis of EPA data. Note: 2022 data is preliminary.

Buying a more fuel-efficient car? Here’s what to know

While saving money on gas may seem attractive, a new car is a big purchase — and buying one should take time and consideration. If you’re looking to upgrade to a more fuel-efficient car, Schulz offers the following advice:

• Always shop around and get preapproved. “The rates you can get from outside lenders will typically be better than what you would get from the auto dealer, so it’s crucial that you take the time to compare at sites like LendingTree and lenders such as local credit unions to try to get the best deal possible,” he says.
• If you don’t need that car immediately, it’s OK to wait and save. “With interest rates as high as they are on auto loans, the less you need to finance, the better,” he says. “It may not be possible based on your circumstances, but if you can put off the purchase and allow yourself to save a little bit more money for a little bit bigger down payment, it can save you some money in the long run.”

Methodology

LendingTree researchers analyzed Environmental Protection Agency (EPA) data for real-world mileage per gallon and CO2 emissions for all vehicles, including all cars (sedan/wagons) and all trucks (pickups, minivans/vans and truck SUVs), as well as manufacturers of these vehicles.

U.S. Department of Transportation (DOT) Federal Highway Administration (FHWA) data was used to find the average annual miles driven per driver by age group in 2021.

To determine the average annual gas price, researchers utilized Bureau of Labor Statistics (BLS) data.