In-depth reviews

Porsche 718 Boxster roadster - MPG, running costs & CO2

The Porsche 718 Boxster’s switch to turbocharged four-cylinder engines has significantly reduced running costs

Porsche 718 Boxster convertible front 3/4 tracking
Carbuyer Rating

4.3 out of 5

Owners Rating

1.5 out of 5

Read owner reviews
MPG, running costs & CO2 Rating

3.5 out of 5

If you’re buying a two-seater, convertible sports car capable of nearly 180mph and a 0-62mph time of around five seconds, then your priorities are likely to lie somewhere other than fuel economy. Still, like all other manufacturers, Porsche is under pressure to reduce its exhaust emissions, and that brings big advantages to buyers, too.

It's also possible that the Boxster may be an owners first sports car, after owning hot hatchbacks or sporty saloons, and the running costs certainly shouldn't be too much of a shock.

Porsche 718 Boxster MPG & CO2

Thanks in part to its fuel-efficient, four-cylinder engine, the entry-level Boxster claims economy of up to 31.7mpg with CO2 emissions of 201-209g/km, resulting in the top rate company-car Benefit-in-Kind (BiK) band of 37%. Unsurprisingly, given it has the same engine and power, the figures are virtually identical for the Boxster T.

If you go for the more powerful Boxster S, running costs increase. The most economical version (fitted with the PDK gearbox) will return around 30.7mpg, dropping to 29.1mpg if you go with the standard six-speed manual gearbox. CO2 emissions span from 218-235g/km.

Considering it's fitted with a 4.0-litre, six-cylinder engine, you'd expect the GTS to be the thirstiest of the Boxster range, so it may be surprising its official figure of up to 28mpg isn't considerably worse. CO2 emissions of 230-247g/km are higher but it has no effect on tax costs under the current system.

All Boxsters cost £150 a year in VED but because the car costs over £40,000, every version faces a £325 surcharge in years two to six, bringing the annual total to £475 during that period.


The Porsche 718 Boxster sits in insurance group 44 out of 50, while the Boxster S sits in group 46. The GTS finds itself in group 49, just one away from the highest band. Considering the car’s technology, power and badge appeal, plus the added vulnerability of a folding fabric roof, insurance costs are predictably high.


All new Porsches get a three-year manufacturer warranty. There are no mileage restrictions and owners also benefit from European roadside assistance within the first three years. This puts the Boxster on par with its rivals from BMW and Mercedes. There’s also the option of adding an extra year onto that initial three-year warranty for extra peace of mind, and extending the warranty can also help you sell the car if and when you decide to do so.


If you’re considering a Boxster, be aware of the fairly significant maintenance costs. Brakes and tyres will both be expensive to replace and will wear out quickly if you put the car through its paces regularly.

Servicing costs will be steep, too. A minor service is likely to cost around £400, with this increasing to more than £600 for a major service. The only silver lining is the fact that these are only required (alternating with one another) every two years or 20,000 miles.

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