How do older gas sippers stand up to the new breeds?
To fully understand a list of the most fuel-efficient cars ever made, we first need to know why humanity started chasing fuel efficiency in the first place.
(This article was originally posted in 2019 but has been updated to include the latest EPA fuel economy figures and new models like the Hyundai Ioniq Hybrid, 2023 Toyota Prius, and the 2023 Lexus ES 300h).
Everything changed for the automotive industry in 1973 when OAPEC (Organization of Arab Petroleum Exporting Countries) dropped an oil embargo on the nations it believed supported Israel during the Yom Kippur War. Japan, the Netherlands, the United Kingdom, Canada, and the United States were the first nations to feel the heat.
Until then, gasoline was plentiful, particularly in the United States, where the muscle car was king. Suddenly, gas stations were closed, and cars were never quite the same again as reality bit. The world realized how reliant on petroleum it was and how quickly things could change.
Honda got a head start on the newfound importance of fuel efficiency. In the mid-70s, Honda's CVVC (Compound Vortex Controlled Combustion) engine met the new American regulations while avoiding using expensive and power-sapping catalytic converters. This also led to the most excellent troll in automotive history as the CEO of General Motors at the time panned Honda's engine, saying, " Well, I have looked at this design, and while it might work on some little toy motorcycle engine, I see no potential for it on one of our GM car engines."
Word got back to Soichiro Honda, and he was unimpressed with the insult, so he had a 5.7-liter 1973 Chevy Impala shipped to Japan. His engineers then built a CVVC system for it, put it back together, and sent it back for the EPA to test. The horsepower remained the same, and the Impala passed the 1975/1976 emissions testing with no loss of fuel efficiency.
Fast forward through the years, and in the 1990s, Toyota started playing with a hybrid electric and internal combustion system that led to the Prius slowly but surely changing the automotive landscape again.
We've left modern plug-in hybrids off this list to keep the playing field level. The list includes the most fuel-efficient non-hybrid cars and the most fuel-efficient gas cars.
The first-generation Prius is slowly becoming the most significant car since the Ford Model T. Without this car, the stunning 2023 model wouldn't be possible.
It started as a concept for Toyota to play with but slowly developed into the most hated production car on the planet while leading the way for the hybrid drivetrain we see everywhere now. It got 40 mpg in the city and managed a healthy 43 miles to the gallon on the highway.
We include an SUV only to prove how far hybrid technology has come. As you can see from the Prius above, it had to have a dull body and blunted performance. These days you can get the same kind of fuel efficiency from a crossover like the Escape.
The Escape Hybrid uses a 2.5-liter NA four-cylinder and an electric motor to produce 200 hp. It's not brisk, but you can feel the benefit of having an electric motor.
To reach 41 mpg, you must opt for a front-wheel-drive model, and only a CVT transmission is available.
It was only sold outside of Japan for one year as the SA310, but we knew it after that as the Suzuki Swift and under its General Motors names of Chevrolet Sprint, Pontiac Firefly, and Geo Metro. It had three cylinders and one liter of displacement but managed a thrifty 39 mpg in the city and 47 on the highway.
While the eighth generation isn't the most popular Civic, it hit all the right notes if you didn't mind your Civic being a bit of a blob to look at.
It competed directly with the 2010 Prius and had the fact it wasn't a Prius on its side but suffered from limited cargo space and a sluggish engine. Around town, it got 40 mpg to the gallon, and on the highway racked up 45 miles to every gallon.
In 1995 Honda was still trying to win the mpg game, and the little 1.5-liter five-speed three-door hatchback delivered. It got a more than respectable 39 to the gallon around town, but out on the freeway, it would cruise along at an astounding 50 mpg without electric assistance.
It's interesting to find a brand-new modern luxury car sandwiched between two golden oldies. The Lexus ES Hybrid is one of the most efficient luxury cars available, and not many of those are available. Most manufacturers tend to focus only on making the car as comfortable as possible, but Lexus gives you luxuries like dual-zone climate control, ten-way power-adjustable seats, and perforated NuLuxe upholstery.
In 1986 the Civic Coupe HF was the compact economy car to own. Practical, fun to drive, and hit 42 mpg around town before swinging for the fences and getting 51 mpg on the highway. All that came ten years before the idea of an electric hybrid was a glint in anyone's eye.
This car was an engineering triumph and will always be known as one of the most fuel-efficient cars ever.
While the Geo Metro was the butt of jokes and a dreadful car, it also developed a cult status and gave birth to the idea of hypermiling as a discipline. It was also incredibly durable, and the 1994 model got 43 mpg in the city.
With a bit of aerodynamic and weight modification and using hypermiling techniques, a 1998 Geo Metro badged as a Pontiac Firefly clocked in 99.7 mpg. Owners of stock 1994 models could expect 52 mpg on the highway.
The earlier Sprint was also rebadged as the SA310. It did 0-60 mph in 15 seconds, weighed 1,600 lbs, and was an absolute death trap in an accident because its lightness wasn't down to high-tech materials. Around town, it got 44 mpg, but it got a more than respectable 53 miles to the gallon on the highway. When launched, it was one of the highest mpg cars ever and remains a top choice in the old cars with the best gas mileage segment.
This is a prime example of old cars with the best gas mileage. You'll find even better examples further down.
The darling of the automotive green movement and owned mainly by the insufferable bores of the world, the third-generation Prius managed to be practical while packing serious technology. It also pulled off a neat trick in having better city fuel economy in the city than on the highway, with 51 mpg and 48 mpg, respectively.
Incidentally, if you don't want the awkward looks of the Prius, a 2023 Corolla Hybrid will achieve the same average consumption as the 2010 Prius.
Currently, the Insight has excellent fuel economy according to the EPA, although real-world experience has varied.
Nearly 20 years after its first iteration, the Insight's city mpg is 55, and its highway reach is 49 mpg. What it can do that its earlier incarnation couldn't? It looks like a normal car, and it can carry people and things.
The Elantra Hybrid uses the same 139 hp and 195 lb-ft hybrid setup as the Ioniq hybrid, but it does without the trick aerodynamics. It just goes to show how vital a slippery car is.
The Elantra is more lavishly equipped than the Ioniq, making it one of the most fuel-efficient luxury cars ever. We use the term luxury in relative terms, however. The big German hybrids were never going to make this list.
Not only did the Honda Insight beat the Toyota Prius to market as the first hybrid car available to the public in the US, but it also had better fuel economy than the Prius. However, what it didn't do was sell well.
The first Insight was limited to two seats, and the smooth rear wheel covers looked silly at the turn of the century. It showed the concept was good, though, and while Honda didn't stay at the forefront of hybrid and electric drive technology, development continued unabated.
Around town, the first generation got 49 to the gallon, but, like the later Prius, it also got better highway economy. The Insight could achieve a massive 61 miles per gallon with a gentle right foot.
The fact that this car is 23 years old and still one of the most fuel-efficient cars of all time is a feather in Honda's cap.
Toyota has refined the Prius to the point there's not much downside unless you dislike its looks. Just look at the all-new 2023 model. In the city, it gets a respectable 43 mpg, but it evens out to 59 mpg on the highway. On top of that, the low operating costs make the fourth-generation Prius extra attractive. The most efficient model also happens to be the Eco entry-level trim, making it more accessible to more people.
With the Ioniq Hybrid, Hyundai gave Toyota stiff competition for a few years. The new 2023 Prius has managed to eke out ahead, but that doesn't mean the car below isn't worthy of your attention.
The Ioniq is a bit lazy, relying on a 04 hp and 109 lb-ft naturally aspirated 1.6-liter engine, but an electric motor adds a helpful 43 hp and 125 lb-ft.
The latest Prius not only looks good, but it's also one of the best gas mileage cars of all time. According to the EPA, the base model can do 58 MPG on the combined cycle. That makes it one of the most fuel efficient cars of 2023.
It will do over 600 miles on a tiny 11.3-gallon tank, which means visits to the gas station are minimal. The upcoming Prius Prime PHEV will likely be even thriftier, but we'll have to wait a few months to find out.
The largest curiosity thrown up by this list is just how fuel-efficient older cars were. That's highlighted by the fact that the Prius has been developed for over two decades but is still comparable in fuel economy with older hybrids and straight-up petrol-powered cars.
The most significant factor is that technology for drivetrain efficiency is developing, but safety standards and legislation have made cars heavier. Things like airbags, side impact bars, rollover protection, crumple zones, and all the extra comfort features we expect on a car add up to a lot of excess weight.
There's also the consideration of pedestrian safety legislation affecting aerodynamics. Add that and the weight of batteries in a hybrid drivetrain, and it's no surprise that little tin cans like the Geo Metro from 32 years ago still rank high as economical cars to run.
We can't talk about fuel consumption without recognizing the fact that driving style plays a huge roll. If you want to get the most out of a tank, read our list of tips that will make your gas last longer.