Parkers overall rating: 4.6 out of 5 4.6

Miles per pound (mpp) Miles per pound (mpp)

Petrol engines 2.9 - 4.2 mpp
Low figures relate to the least economical version; high to the most economical. Based on WLTP combined fuel economy for versions of this car made since September 2017 only, and typical current fuel or electricity costs.

Fuel economy

Petrol engines 21.4 - 31.7 mpg
  • Surprisingly close between four- and six-cylinder models
  • Maintenance costs won’t be cheap
  • But two-year service intervals welcome

How much does it cost to run?

Let’s not beat around the bush: the Porsche 718 Cayman is not going to be a cheap car to run. But for a car of this type and pedigree, it needn’t break the bank, either. And anyone who can afford the £40k+ price tag won’t baulk at the cost of running this two-seater.

MPG and CO2

All models come with stop-start, with CO2 emissions surprisingly close between the four- and six-cylinder cars (making you wonder what the benefit of losing two pistons was in the first place).

  • Cayman: 29.1-31.7mpg 201-220g/km
  • Cayman T : 29.4-31.7mpg, 202-218g/km CO2
  • Cayman S: 27.4-29.4mpg, 217-235g/km
  • GTS 4.0: 25.9-28mpg, 230-247g/km
  • GT4: 25.4-26.4mpg, 242-251g/km

In the real world, we found ourselves averaging closer to 30mpg in the four-cylinder Cayman S, although you’ll see mid- to high-30s if you’re careful. The flipside? Enjoy a fast blast and fuel economy will quickly sink to the 20s, if not lower.

Even the GTS 4.0 isn’t far off, with mid 20s around town and reaching low-30s on a motorway cruise with the help of cylinder deactivation. A full tank of fuel predicted a range of around 370 miles, so filling up shouldn’t be too often.

Balance fuel costs with the fact that all Porsches require servicing only every two years or 20,000 miles, bringing welcome relief from big bills on a regular basis.

However, Porsche dealerships aren’t renowned for being cheap to use – you can expect hefty charges for consumables such as tyres, brake pads and exhausts, particularly if you take your car on track, so make sure you factor those into your budgeting.

How reliable is it?

  • Proven platform, few known faults
  • Recall history is good on Cayman
  • Smaller 4-cyl engines still to be proven

The Cayman has been around in one form or another since 2006 and has established a strong reputation for reliability with few known mechanical problems. Earlier issues, such as “trunk clunk” – when the tailgate would rattle over bumps in the road – have largely been ironed out.

First-generation Cayman models were at risk of bore scoring and failed IMS bearings, but an analysis among Porsche experts reveals the risk of a shattered six-cylinder engine was lower than the paranoid fear factor you may detect in internet chatrooms.

However, it is true to say that the new four-cylinder engines are relatively new before we assess mechanical integrity at this point – the same can be said for the six-cylinder motor in the GTS and GT4. Even though it’s also used in the 911, it simply hasn’t been around long enough for us to comment.

Parkers will update this section as we receive more intelligence from owners and the trade.

Ongoing running costs

Road tax (12 months) £220 - £520
See tax rates for all versions
Insurance group 42 - 48
How much is it to insure?