In-depth Reviews

Mazda3 hatchback - MPG, running costs & CO2

The SkyActiv-X petrol is a real Mazda3 selling point

Carbuyer Rating

4.0 out of 5

Owners Rating

4.5 out of 5

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MPG, running costs & CO2 Rating

4.0 out of 5

Mazda has a proud history of ‘doing things differently’ when it comes to engine technology. In recent years, the brand has shunned the trend for 'downsizing' for its petrol and diesel engines, instead saying it "rightsizes" its models. Its 2.0-litre petrol model has a larger engine than most rivals for that reason, including the Ford Focus, which has 1.5 and even 1.0-litre units.

Mazda's SkyActiv-X petrol uses a clever ignition system that blends high-pressure diesel engine technology with conventional petrol logic to deliver impressive performance and running costs. If you can afford it, it's our pick of the range.

Mazda3 MPG & CO2

The 2.0-litre SkyActiv-G petrol manages around 45.6mpg, thanks to 24V mild hybrid technology and the ability to shut down cylinders under light throttle. With CO2 emissions of just under 120g/km, it's an affordable choice for company-car drivers.

The SkyActiv-X engine is even more frugal and efficient, returning up to 51.4mpg and emitting as little as 100g/km of CO2 with 16-inch alloy wheels fitted, giving it the lowest BiK liability in the range. Fitting bigger wheels and an automatic gearbox can see these figures drop below 50mpg, while CO2 climbs to a maximum of 125g/km.

The 1.8-litre SkyActiv-D diesel engine was discontinued in 2019. This engine produced 56.6mpg under the WLTP testing cycle and CO2 emissions of 107g/km when equipped with a six-speed manual gearbox. If you specify the automatic gearbox, you'll need to bear in mind that the diesels will only just manage 50mpg, CO2 emissions also increase to up to 127g/km making it more costly to run.

Insurance groups

Insurance groups for the latest Mazda3 SkyActiv-G petrol start from 15 for an SE-L trim and go up to 17 for a GT Sport Tech range-topper, the same groups occupied by the SkyActiv-D diesel.


Mazda offers a three-year, 60,000-mile warranty, which puts it on an equal footing with rivals from Ford and Volkswagen. It looks a bit stingy next to Hyundai's five-year/unlimited mileage offer and Kia's seven-year/100,000-mile warranty, however.

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