Those looking to buy an economical car would normally think that diesel power is their best option, but what if you don't do much driving out of town or prefer petrol power?
Here's our round-up of the most economical petrol cars on the market today.
Peugeot 108 1.0 - official 68.9mpg, True MPG 54.6mpg
The 108 isn't our favourite city car but it is the most economical petrol non-hybrid petrol car we've tested. It's also worth looking at our favourite city car, the Hyundai i10. It can't match the Peugeot for real-world fuel economy but it is much better to drive, has room for five and comes with a five-year warranty. The i10 with a 1.0-litre petrol engine achieved 45.6mpg in True MPG testing while the 1.2 returned a still respectable 42.6mpg.
Toyota Yaris 1.5 VVT-i Hybrid - official 78.5mpg, True MPG 57.8mpg
The Yaris Hybrid doesn't achieve its official figure of 78.5mpg but it still returns a respectable 57.8mpg. The Yaris is expensive to buy in hybrid form, though, so it's worth doing the sums to see if makes financial sense for you. Our Car of the Year 2015, the Skoda Fabia 1.2 TSI 90 SE returns 44.9mpg - less than the Yaris but it is nearly £3000 cheaper to buy and a better all-rounder.
Peugeot 308 1.2 PureTech 130 - official 61.4mpg, True MPG 49.6mpg
The 308 is a stylish family car that's also cheap to run. It's let down by the cramped rear seats but it does have a large boot. A more spacious family car that's worth considering is the Skoda Octavia. It's also available with a 1.2-litre petrol engine and it achieves 44.2mpg in real-world testing.
Toyota Auris Touring Sports 1.8 VVT-i Hybrid - official 76.3mpg, True MPG 58.7mpg
With an impressive True MPG of 58.7mpg, the Toyota Auris Touring Sports Hybrid is the most efficient petrol-powered car the True MPG team has tested. It's a practical estate car that is worth considering as a company car.
Ford C-Max 1.0T 100 Ecoboost - official 55.4mpg, True MPG 41.7mpg
Ford's 1.0-litre Ecoboost engine works well in the C-Max. It's got enough power to cope with the C-Max's size and returned 41.7mpg in our True MPG tests. There's plenty of room for four and it's also pretty decent to drive.
Toyota Verso 1.6 V-matic - official 42.8mpg, True MPG 39.0mpg
If you need to carry seven people and are looking a comfortable MPV that's also reliable, the Toyota Verso 1.6 V-matic is worth a look. It's the most economical 7-seater our True MPG team has tested, returning 39.0mpg in real-world testing.
Lexus GS300h - official 60.1mpg, True MPG 51.4mpg
The Lexus GS300h is a great option for company car tax buyers. Its CO2 emissions are impressively low and it comes with loads of standard equipment. Fuel costs will also be low, thanks to a True MPG of 51.4mpg.
Citroen C4 Cactus 1.2 PureTech 110 S/S - official 60.1mpg, True MPG 50.0mpg
Citroen has tried to reduce as much weight as possible from the C4 Cactus to keep running costs low. It's also made it stand out from the crowd with funky styling, Airbumps and bright colours. The weight-saving efforts have paid off. The 1.2 PureTech 110 S/S is most efficient petrol small SUV we've tested achieving 50.0mpg.
Lexus NX300h - official 54.3mpg, True MPG 45.5mpg
A large SUV that returns 45.5mpg in real-world driving conditions looks very tempting. Add to that the low company car tax rate and Lexus's reputation for reliability and the NX300h is a tempting prospect. It might not be as good to drive as the BMW X3 but its low running costs could steal buyers.
Still unsure whether diesel or petrol power is right for you? Check out our comparison of fuel types to help you decide which is best. Click here for more.
Our True MPG team tests new cars every week and you can find the results here.