Porsche 911 GT3 2017-2021 Reliability & Common Problems

Is the Porsche 911 GT3 reliable?

Overall, the 991.2-generation GT3 is a reliable car and far more durable than the pre-facelift model it replaced.

Early 991 GT3s were at risk of catching fire due to an issue relating to the engine's connecting rods, and after a number of incidents, Porsche recalled all cars to rectify the problems that afflicted the 3.8-litre unit.

While the 4.0-litre engine isn't totally free of faults, it is much more robust thanks to its use of stronger materials – many owners have covered big miles without fault.

Considering how highly strung the engine is, we'd recommend a full Porsche warranty for peace of mind.

Engine: The 4.0-litre is far more robust than the 3.8-litre unit, but there have been a few cases of engine failure, variously attributed to causes such as oil starvation or low cylinder compression. Porsche often covers engines under warranty, but be sure to check the service history.

Gearbox: Issues with both the manual and PDK ’boxes are rare but make sure gearshifts are smooth because a replacement for either is obscenely expensive.

Brakes: Be wary of cars fitted with carbon-ceramic brakes. Their stopping power is unrivalled but they can cost between £10k and £13k to replace. Make sure they’re not worn or pitted.

An owner’s view

Robin Titterington: “After driving my friend’s GT3 RS, I knew it was time to buy one myself. The RS was a bit over the top for me, so I bought a 991.2 GT3 with Comfort seats and carbon-ceramic brakes. It’s a brilliant car and one that’s better suited to ‘normal’ driving.

My car’s Michelin Pilot Cup 2 tyres generate a lot of noise so I intend to swap these for Pilot Sport 4s. For peace of mind, I bought an extended warranty, but I’ve had no issues so far. It’s an exceptional car and I’d recommend it to any sports car enthusiast.”

Also worth knowing

Not all GT3s have full-bucket seats. If you’re after a more road-biased car, you’ll have no trouble finding a GT3 with electric Comfort seats. Alternatively, there are carbon-backed Sport seats, which look superb and are reasonably comfortable.

The Clubsport package comes with a full roll-cage and a fire extinguisher, so it is worth considering if you plan to use your car for track days.

Sam Phillips

Title: Staff Writer

Sam joined the Autocar team in summer 2024 and has been a contributor since 2021. He is tasked with writing used reviews and first drives as well as updating top 10s and evergreen content on the Autocar website.

He previously led sister-title Move Electric, which covers the entire spectrum of electric vehicles, from cars to boats – and even trucks. He is an expert in new car news, used cars, electric cars, microbility, classic cars and motorsport.

Sam graduated from Nottingham Trent University in 2021 with a BA in Journalism. In his final year he produced an in-depth feature on the automotive industry’s transition to electric cars and interviewed a number of leading experts to assess our readiness for the impending ban on the sale of petrol and diesel cars.

Matt Prior

Title: Editor-at-large

Matt is Autocar’s lead features writer and presenter, is the main face of Autocar’s YouTube channel, presents the My Week In Cars podcast and has written his weekly column, Tester’s Notes, since 2013.

Matt is an automotive engineer who has been writing and talking about cars since 1997. He joined Autocar in 2005 as deputy road test editor, prior to which he was road test editor and world rally editor for Channel 4’s automotive website, 4Car.

Into all things engineering and automotive from any era, Matt is as comfortable regularly contributing to sibling titles Move Electric and Classic & Sports Car as he is writing for Autocar. He has a racing licence, and some malfunctioning classic cars and motorbikes.