The future is electric. If we like it or not, gasoline will start to become obsolete and electric cars with supercharging will be the next big thing. Pure electric cars are not yet reachable where every American can have them due to the way they currently charge and their price, so the next best thing is the hybrid segment.
Let’s do a comparison real quick
Do you want to save on gas? Well, hybrids are fantastic. Batteries can be expensive from an OEM distributor and by getting a dealer to replace them. Yeah, that would be pricey. There are ways to save loads of money buying certified aftermarket batteries. A battery bought from a dealer will run roughly 4k dollars every 100k miles. 100k miles at 50mpg at 3$ per gallon is $6,000. A typical car will average about 20 MPG, which adds up to be $15K per 100k miles in just gas. So, if you buy an OEM replacement battery for a Prius and get it changed by the dealer, you will still be looking at $5,000 in savings per 100k miles. And you can find the batteries much cheaper and you can get a lot better gas mileage if you are wise.
Well, today I am going over 5 most fuel-efficient hybrid cars that are all under 10k, well only one is 10k and the rest are under 5k and the last one may surprise you because it is not a hybrid, let us get started!
2000-2006 Honda Insight (61-68MPG, 73 HP)
The Honda Insights is the first hybrid car sold in the US. Yes, the Insight beat the Toyota Prius. Sharing the same assembling factory as the Honda s2000 and Acura NSX in Suzuka Japan. Both the NSX and the Insight are aluminum bodied, and the s2000 has an aluminum hood. The investment Honda took into the Light chassis and its very aerodynamic body is really what helps this car receive its 61-68mpg. This car is still the most fuel-efficient vehicle sold in the US, in regard to non-plug-in hybrids. Just like the Honda s2000s, the gauges are digital which is advanced for the time. For the price, the basic feel of the interior is really all you need, really.
This car is funny looking
I know this car looks funky; you are not buying a fuel-efficient car for the looks. Not even the bad ones. I have talked about the insight previously on one of my videos and there are owners who commented in the description saying they have reached near 100miles per gallon 
, which is insane. Not only can these cars get insane gas mileage, but they are also way reliable. This one has over 400k miles, and that is not unheard of.
Here is one for sale with only 56k miles for $5300. And I am 100% positive they would take 5k. Which is a great buy. 
2004 – 2009 Toyota Prius (60-51 MPG, 110 HP)
The Prius must be the runner up, I mean it must be. Before 2006, which is when the Toyota had a slight refresh, only had cloth interior, and painted surfaces on the dash. The cloth interior was a severe downfall for this generation of Priuses and the painted dash in front of the steering wheel and passenger would easily scratch up.
Updates in 2006
Toyota introduced a leather interior after 2006, which resolved the tearing up of the interior issue. Toyota also gave the painted dash a more rugged texture which was more resilient to scratches. In 2006 the Prius started to receive a rear-view camera which is important due to its low visibility, so I would opt for a post 2006 model. Like the Honda insight, both are very aerodynamic which helps with the gas mileage and the Prius received 60-51 MPG. The cool thing about these Toyota Priuses, the batteries can last upwards to 200k+ miles. And the car itself can easily see 300k miles. Here is one going for $3,000 with 140k miles. Yes, it is ugly.
2012-2015 Toyota Prius C (53-46mpg, 99hp)
The Toyota Prius C is basically the newer and more attractive Prius designed into a smaller hatch back configuration. Keep in mind, all while keeping the Priuses typical functionality, which is a lot easier on the eye. I do not absolutely hate it. The C in the name basically means city. Toyota tried to build a car that appealed more towards the younger crowd with its sharper design and styling cues. The MPG is not nearly as nice as the standard Prius on the highway with its 46mpg, but in the city it makes up for that with its 53-mpg rating.
The C is geared more towards the younger crowd
To market to such a crowd, the Prius does have a bit more of an agile feel, sportier suspension and weighing 500lbs less than the typical Prius. This car even has an eco-score system letting you, the driver, know just how inefficient you are driving. It even averages the ranking to the past 100 drives. The interior is kind of nice, it is a bit stylish throughout the interior and exterior, but once again, it is not anything crazy. 
This 2015 Toyota Prius C is going for 10k dollars, which is the most expensive car on this list, and it has under 100k miles. Depending how modern you would like your car, this could be a decent buy.
2006-2011 Honda Civic Hybrid (40-50MPG, 110 HP)
Being the first model of the eight gen Honda civic with more of a space, futuristic look to the car. It has the same IMA electrical system as the Honda Insight but with an upgraded 1.3L motor, which is why it has 110 hp compared to the 73 hp the insight has. But that also means it is not going to be nearly as comparable in the gas mileage that the Insight has, but it is still competitive in the hybrid market. Honda tried to target the younger crowd with its sportier suspension and very responsive steering and handling before Toyota made its move in 2012. After all, Honda has a “Sport mode” in this car. The hybrid Honda Civic is not sporty. Adding this mode is very weird especially for such a bland car.
Check this out to see its common issues: Honda Civic 2006-2011 Common Issues 
This one is going for $5,000 with 107k miles. its better looking than the insight, but if I am buying a car for its efficiency, the insight beats this civic.
1989-1994 Geo Metro (53-58 MPG, 55HP)
Yes, I bet you did not expect this nugget on the list. no, it is not a hybrid vehicle, but it is competitive with most hybrids on the market, even in today’s standards! it has a 1l I3 engine made by Suzuki in the Hamamatsu, Japan which was partnering with GM as a joint venture. You can grab this thing as a mini hatchback in a 2 or 4 door configuration, and even a convertible that received a combined 55mpg.
I have encountered one in my life..
My mom had one of these and it just would not die. I do not even remember when she ever filled it up with gas. It was a cool crappy car! The plastic window on this convertible is torn and the wipers do not work properly. Do not worry, I fixed that with zip ties when I first started working on cars as a wee tod.
Hey, it worked!
She bought it for about $400.
Basically, you can grab yourself this crappy car that gets great gas mileage and will keep chugging along until you just let it die. I have seen people convert the hatch back ones into little trucks. Or Utes and It looks sick. Here is a road worth Metro going for $1,000, 
If they are not beaten to death, The Geo Metro should last a little over 200k miles. sometimes more. That’s 1k for 50k miles, which is fantastic.
That is it!
If I had to pick one for myself and my main goal is fuel efficiency, I would grab the Honda Insight. It was revolutionary for the time and it has by far the best gas mileage. But the Geo Metro would be a pretty cool project. It really all depends what kind of budget you are on.
Which one would you pick?
If you don’t want to read all of this, watch this instead: https://youtu.be/FBAO7GxcVuY