From hatches to muscles, cars of all shapes and sizes are adopting green technology. Whether autonomous cars will become a reality or not is a different question; electric cars are the future. Even though the ‘EV’ cars were introduced barely a decade ago, the kind of transformation and innovations we’ve seen in the last couple of years makes the whole thing look like a yesteryear concept. In this article, we’ve listed out the ten most fuel-efficient vehicles.

But before that, let’s just put the basic questions to rest once-in-for-all: the difference between EV, Hybrid, and Plug-in Hybrid - an electric vehicle is the one that runs solely on electric power. You don’t have a combustion engine here whatsoever. A hybrid engine is the one where the car will charge its own batteries on the run with the gasoline engine. As for the plug-in hybrids, the car can be plugged into electricity points to charge the batteries. Now that we have clarified the obvious and bored you enough, let’s move on to the heart of the article.

2014 - 2017 BMW i3 Rex

One of the best-selling EVs of all time, the BMW i3 is a cute hatchback that comes with an electric powertrain and a single-speed transmission. The little car went on to give a mileage of 88 mpg combined, making it the most fuel-efficient car to date. To make it more efficient, BMW added an optional 0.6-liter, two-cylinder petrol engine that produced 34 ponies to give it an extended range. The 2017 i3 REx came packed with an improved 33 kWh battery, a 50-percent capacity increase over the previous year’s 22 kWh battery pack.

Apart from carrying the BMW marque, the i3 REx came with a carbon-fiber reinforced plastic body shell on the outside. On the inside, it got a wide cabin, an expansive dash with optional open-pore wood trim, and a pair of digital displays - one behind the wheel and the other on the center of the dash. The i3 REx retails at $48,000.

Read our full review on the 2014 - 2017 BMW i3 Rex.

2017-2018 Toyota Prius Prime

Launched in 2017, The Toyota Prius Prime succeeded the first-generation Prius six years after its launch. The car came as an improved version of the first-gen model and delivers an EPA rating of 78 mpg this time around. The Prius Prime is powered by Toyota's Hybrid Synergy Drive (HSD) powertrain that combines a 1.8-liter, four-cylinder, Atkinson-cycle engine. It also has a dual motor generator drive system that is powered by an 8.8 kWh battery. One can switch between multiple drive modes to extract the best range in any given situation. On a full tank of fuel and electric charge, the Prius Prime can travel around 640 miles; which is good but lags behind the likes of the Hyundai Sonata and Chevrolet Volt.

The Prius Prime has all the curves and figures to attract attention on the road. The car’s USP is ‘the design of the dual-wave rear glass hatch that flows into the rear spoiler for enhanced efficiency.’ It also has LED lights and a carbon-fiber reinforced body. On the inside, the Prime has a posh interior with a mighty-big 11.6-inch Infotainment System and heated front seats, to name a few. Although the Prime has been losing steam (pun intended) lately, it has been doing very well in the U.S.; which also happens to be its best market currently. The starting price of the Prius Prime is $27,000.

Read our full review on the 2017-2018 Toyota Prius Prime.

2016-2018 Chevy Volt

As one of the senior-most members of the electric-passenger vehicle segment, the Chevrolet Volt gets a mention on this list. While it may not have the lowest running cost, it doesn’t lag behind by any means. The Volt was launched in 2010 and is currently in its second iteration. This second-gen Volt came with an upgraded 1.5-liter, four-cylinder petrol engine and an 18.4 kWh battery pack, that allowed the new Volt to deliver better EPA ratings than its predecessor - 77 mpg combined.

Now, what makes this plug-in hybrid from Chevy different from the others is that this car will run on battery in the beginning, and then switch to gasoline if needed. There is no drive selection mode per se, wherein you can switch from battery to gasoline, or vice versa as per your needs. As for the conveniences, the Volt has an infotainment system with Apple CarPlay and Andorid Auto, and an app, which allows you to start your car, lock/unlock it, etc. using your mobile phone. Pretty neat, isn’t it? The Volt starts at $33,000.

Read our full review on the 2016-2018 Chevy Volt.

2019 Honda Clarity PHEV

This Honda product is one of the safest bets if you’re in the market for a ‘green vehicle.’ Providing a combined EPA rating of 76 mpg, the Clarity Plug-in has a 1.5-liter, four-cylinder gasoline engine, and a 17 kWh battery connected to an electric motor. To dig a little deeper into the technicals, the Clarity is a serial hybrid, in which the internal-combustion engine is used to turn a generator that produces current to charge batteries for an electric motor that primarily drives the vehicle. This is unlike more typical parallel hybrids such as the Toyota Prius, where the internal-combustion engine and electric motors both are mechanically connected to the transmission to propel the vehicle.

The Clarity is a typical Honda from the inside - very spacious, and ergonomically perfect. With that said, there’s nothing to be excited about in this car; it does its job, and that’s it. If Honda wants the Clarity to look like a strong competitor, it better add bells and whistles, like its competitors, to this otherwise ‘bland car.’ The Clarity starts retailing at $34,000.

Read our full review on the 2019 Honda Clarity PHEV.

2019 Hyundai Ioniq PHEV

The Ioniq was initially launched as a hybrid car, then as an electric one, and finally as a plug-in hybrid. Despite having a small 8.9-kWh battery pack (when compared to the competition), the Ioniq manages to deliver 76 mpg according to the EPA ratings. The powertrain combines a 45 kW electric motor and a 1.6-liter, four-cylinder engine. The Ioniq is capable of running 22 miles in all-electric mode, after which it switched to the combustion engine.

The Hyundai Ioniq is perhaps the most driver-friendly car amongst other plug-ins; thanks to a dual clutch transmission, which is different from the segment norm - a CVT gearbox. The South Korean car also has two drive modes to choose from – Eco and Sport – former one for better efficiency, and the latter for performance. The cabin fit-and-finish is what you expect from a Hyundai. In addition, the Ioniq gets a sunroof, LED lights, Cruise Control, 8-inch infotainment system, and wireless charging as add-ons over the standard nothing-to-write-home-about features. The car has a starting retail price of $25,000.

Read our full review on the 2019 Hyundai Ioniq PHEV.

2018 Kia Niro PHEV

This plug-in Crossover from Kia has an EPA rating of 66 mpg and comes with a combined powertrain that includes a 1.6-liter, four-cylinder engine and an electric motor to produce a total of 139 horses. Like the Ioniq, the Niro Plug-in also has a dual clutch transmission. The Niro Plug-in comes packed a 9-kWh battery, which is sufficient for up to 26 miles of all-electric range.

With its relatively higher clearance and spacious interior, it serves as a good family car compared to typical compact SUVs seen on the market. The exterior has a please all, offend none style, although its shape doesn’t especially stand out on roads filled with similar Asian and American commuter cars. The Niro Plug-in is a practical commuter that will keep you happy at all times with its neutral driving dynamics. In top-spec, this car can be availed with LED lighting all around, heated outside mirrors, an 8-inch touchscreen display, Harman Kandor audio system, and Park Assist, to name a few. The Niro starts at $28,000.

Read our full review on the 2018 Kia Niro PHEV.

2017 - 2018 Kia Optima PHEV

The Kia Plug-in Hybrid is similar to its siblings and cousins at Hyundai. The Optima delivers 61 mpg combined, as per the EPA ratings. Under the hood, the Optima has a 2.0-liter, four-cylinder engine and an electric motor that delivers a combined output of 202 horsepower, making it one of the most powerful cars on this list. A 9.8-kWh battery pack enables the Optima to drive 29 miles without the help of the combustion engine. Power is sent to the front wheels via a six-speed automatic transmission. If plugged into a 240-Volt connection, the Optima can be charged from naught to a 100-percent in under three hours.

While the car seems big and spacious, five passengers will be a tight fit. Kia seems to have used durable parts inside, which will last long. Apart from the standard fare utilities, the Optima has an 8-inch touchscreen infotainment system that supports Android Auto and Apple CarPlay, Cruise Control, and Active Eco System. Most of the safety features like Blind Spot Detection, Park Assist, Autonomous Braking System, etc. come as optional. The starting price of the Kia Optima Plug-in is $24,000.

Read our full review on the 2017 - 2018 Kia Optima PHEV

2016 Hyundai Sonata PHEV

Doesn’t it look like the South Korean companies have dominated this list? Well, that’s because they are efficient performers. Here’s another one – the Sonata. Let’s start off with the most essential point; the Sonata Plug-in delivers 59 mpg. The car can go up to 29 miles in all-electric mode thanks to the same 9.8-kWh battery that powers the Optima as well. It gets a 2.0-liter, four-cylinder engine and an electric motor that produce 193 ponies combined! Power is sent to the front wheels via a six-speed transmission. Recharging the battery from naught to 100 takes around three hours.

The Sonata Plug-in has quite a lot in terms of features. The car has a heated steering wheel, wireless charging pad, second-row USB ports, a 7-inch touchscreen system that supports Apple CarPlay and Android Auto, automatic emergency braking, LED headlights, lane assist, and driver attentiveness monitoring. The car retails at $39,000.

Read our full review on the 2016 Hyundai Sonata PHEV.

2017 - 2018 Hyundai Ioniq Blue

If you still haven’t understood, Ioniq stands for Ion+Unique. Not to be confused with the Ioniq Plug-in, the Ioniq Blue is actually a hybrid car. The Ioniq Blue is the base trim of the Ioniq, delivering 58 mpg in a combined effort. It gets a 1.6-liter, four-cylinder engine and an electric motor mated to a six-speed automatic transmission. It comes packed with an 8.9-kWh battery, enabling it to run 22 miles purely on battery charge.

If you’re looking at an alternative to the Prius, this should be your pick. The Ioniq Blue is actually pretty loaded for the price it commands; it gets rear-view camera, automatic headlights, puddle lamps, 7-inch touchscreen infotainment system with Android Auto and Apple CarPlay, Keyless Entry and Push Start button. The car is available at a starting price of $22,000.

Read our full review on the 2017 - 2018 Hyundai Ioniq Blue.

2012 - 2017 Toyota Prius PHEV

Despite being succeeded by the second generation, the first-gen Prius Plug-in still finds a mention here as not many new cars have been able to replicate the success of this foregone model. Back then, the Prius came with a 1.8-liter, four-cylinder gasoline engine, and two electric motors. A humble 4.4-kWh battery powered the electric motors that allowed the Prius to drive for 11 miles without using the combustion.

The first-gen Prius Plug-in was a runaway success, with the company selling more than 75,400 first-generation Prius Plug-ins worldwide from 2012 to 2016. The car’s biggest market was the U.S, where 42,345 first-generation units were sold. In terms of interior, the car had the basic necessities. When launched, the car was priced at $25,000.

Read our full review on the 2012 - 2017 Toyota Prius PHEV.