Porsche 911 Cabriolet - MPG, running costs & CO2

It might have high costs by typical standards, but the 911 is reasonable given its sheer performance

Carbuyer Rating

4.3 out of 5

MPG, running costs & CO2 Rating

4.0 out of 5

Porsche is renowned for building powerful engines, but to achieve such great performance, they are also efficient by default. That's especially the case now the era of turbocharged Porsches is well and truly upon us, improving fuel-efficiency when you aren't trying to set a new personal best at a trackday.

Porsche 911 Cabriolet MPG & CO2

Both the Porsche 911 Cabriolet Carrera S and four-wheel drive Carrera 4S achieve a fuel economy figure of around 27mpg. Strict new WLTP tests makes this look like a small increase in consumption compared with the previous model, but the new regime means it should be far easier to achieve this number in real-world conditions, and Porsche cites efficiency gains from its engine and new eight-speed dual-clutch automatic gearbox.

The significant increase in power from the 3.8-litre engine in the Turbo S comes with a similar drop in economy, so 22.6mpg is the best it can muster. Still, this isn't bad compared with cars of similar performance.

If you're looking for a drop-top sports car, the 911 Cabriolet's running costs certainly shouldn't put you off compared with rivals like the Audi R8 Spyder or McLaren 570S Spider.

It's impressive that the four-wheel drive version is almost as efficient as the Carrera S, and both have CO2 emissions of just over 200g/km. Even so, every version of the latest 911 still sits in the top 37% Benefit-in-Kind (BiK) band for business use, should you try and wangle one as a company-car. While there's no effect on running costs, the Turbo S is more polluting, with 284g/km in tailpipe CO2 emissions.

Insurance groups

Every version of the Porsche 911 Cabriolet sits in group 50, the top ranking. That's par for the course with cars like this, but it's worth checking how much insurance will cost, especially if you live in a city without a garage.


Porsche 911s come with a three-year/unlimited-mileage warranty, which is fairly typical for luxury marques. The bodywork and paint are also covered for 12 years (against corrosion) and three years respectively.


It's impressive to note, that given the 911 Cabriolet's performance, it only requires servicing once every 20,000 miles. In reality, though, most owners are likely to get their 911 serviced annually, and this can be quite pricey. Expect to pay £500 or more, even for routine maintenance.

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