2018 Porsche 911 Carrera S Cabriolet — Full Specifications
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The 2018 Porsche 911 Carrera S Cabriolet is a coupe powered by a 3L 6-cyl turbo premium gasoline engine. Its most fuel-efficient configuration returns around 29 mpg (UK) / 24 mpg (US EPA) combined, with 28–29 mpg (UK) across all configurations. Owners often keep a Porsche 911 Carrera S Cabriolet workshop manual to hand for servicing and repairs.
Related listing: see also the 2018 Porsche 911 Carrera page for the base 911 Carrera listing, which may cover additional engines and body styles.
Compared with the 2017 Porsche 911 Carrera S Cabriolet: Fuel economy is essentially unchanged at around 29 mpg (UK) combined. The engine line-up listed by EPA is unchanged.
Full Specifications
| Engine | 3L 6-cyl turbo |
|---|---|
| Transmission | Automatic (AM-S7) |
| Fuel Type | Premium Gasoline |
| Powertrain | Conventional |
| Drive | Rear-Wheel Drive |
| Body Style | Coupe |
| Passenger Volume (EPA) | 68 cu ft (1,926 L) |
| Luggage Volume (EPA) | 5 cu ft (142 L) |
| Fuel Economy (UK) | 29 combined / 26 urban / 34 extra-urban mpg |
| Fuel Economy (US EPA) | 24 combined / 22 city / 28 highway mpg |
| CO₂ Emissions | 228 g/km |
| EPA Greenhouse Gas Score | 5 / 10 (10 = lowest emissions) |
| EPA Est. Annual Fuel Cost | $3,400 (15,000 mi/yr, US prices) |
Engine & Transmission Options
EPA lists 2 configurations for the 2018 Porsche 911 Carrera S Cabriolet, all with the 3L 6-cyl turbo engine. Combined fuel economy ranges from 23 to 24 mpg (US), or 28 to 29 mpg (UK), depending on engine, transmission and drive. The headline figures at the top of this page describe the most fuel-efficient configuration.
| Engine | Transmission | Drive | MPG (UK) | MPG (US) | CO₂ g/km | Fuel cost / yr |
|---|---|---|---|---|---|---|
| 3L 6-cyl turbo | Automatic (AM-S7) | Rear-Wheel Drive | 29 | 24 (22/28) | 228 | $3,400 |
| 3L 6-cyl turbo | Manual 7-spd | Rear-Wheel Drive | 28 | 23 (20/28) | 243 | $3,550 |
MPG (US) shows combined, with city/highway in brackets. Highlighted row = the configuration used for the headline figures. Source: US EPA fueleconomy.gov.
EPA measures interior passenger volume at 68 cubic feet (about 1,926 litres) and luggage volume at 5 cubic feet (about 142 litres). These are US EPA interior-volume figures; they are measured differently from the boot capacity numbers UK manufacturers quote.
Owner Essentials for the 2018 Porsche 911 Carrera S Cabriolet
Running Costs: 2018 Porsche 911 Carrera S Cabriolet
Covering around 8,000 miles a year in a 2018 Porsche 911 Carrera S Cabriolet at 29 mpg combined, expect roughly 1,254 litres of fuel annually — multiply by your local price per litre for a cost estimate. For US owners, the EPA estimates about $3,400 a year in fuel for the most efficient configuration (15,000 miles, national average prices). Work out exact fuel costs with the fuel cost calculator on 247Calculators.
Convert between MPG and L/100km with the unit converters on 247QuickTools. Not sure what tyre size fits? 247TyreCheck explains tyre sizing.
Only need this car occasionally? See our buy vs rent comparison.
2018 Porsche 911 Carrera S Cabriolet Safety Ratings (NHTSA)
No NHTSA crash-test rating is on record for this model year. The NHTSA rates only a subset of vehicles each year; you can browse every rated vehicle on our NHTSA Safety Ratings hub.
Recalls & Owner Complaints (NHTSA)
NHTSA lists no safety recall campaigns for the 2018 Porsche 911 Carrera S Cabriolet as of 6 October 2026. Recalls can be issued years after a model is sold, so it is still worth checking your own VIN.
Owners have filed 1 complaint with NHTSA about the 2018 Porsche 911 Carrera S Cabriolet. The most-reported areas are Electrical system (1).
Used-buyer checklist for the 2018 Porsche 911 Carrera S Cabriolet
Based on where NHTSA recalls and owner complaints cluster for this model year, these are the areas worth checking before you buy:
- Electrical system (1 owner complaint) — Test every switch, window, light and warning lamp on a test drive, and ask about battery or alternator replacements.
Source: US NHTSA recall and consumer-complaint databases, retrieved 6 October 2026. Complaints are unverified owner reports, not confirmed defects. Check any vehicle by VIN at nhtsa.gov/recalls, and see our guide to checking a used car for recalls.
How It Compares
How does the Porsche 911 Carrera S Cabriolet compare to similar coupes? For context, coupes in our database average around 25 mpg (UK) combined — this model's 29 mpg figure is 4 mpg better than that average. Its 228 g/km CO₂ figure is 50 g/km lower than the 278 g/km average for coupes on this site. This comparison is based on 1072 coupes in our dataset.
Porsche models in our database average about 26 mpg (UK) combined on their most efficient configuration; the 2018 Porsche 911 Carrera S Cabriolet's 29 mpg is 3 mpg above that make average. Its 228 g/km CO₂ figure is 26 g/km lower than the 254 g/km Porsche average.
Of the 17 Porsche 911 Carrera S Cabriolet model years we cover, the 2018 is the most economical on its best configuration (29 mpg UK combined). See every Porsche 911 Carrera S Cabriolet year side by side.
Last updated: · Data: US EPA (fueleconomy.gov) and NHTSA safety ratings 18 July 2026; NHTSA recalls and complaints 6 October 2026; Wikidata & curated EU catalogue 18 July 2026; European generation and engine data from Wikipedia 7 October 2026
Vehicle data sourced from manufacturer specifications. Always verify with your vehicle handbook or a qualified mechanic. This is a reference tool, not professional advice.
Recommended Accessories for the 2018 Porsche 911 Carrera S Cabriolet
Frequently Asked Questions
What engine does the 2018 Porsche 911 Carrera S Cabriolet have?
It's fitted with a 3L 6-cyl turbo premium gasoline engine, paired with a automatic (am-s7) transmission.
What is the fuel economy of the 2018 Porsche 911 Carrera S Cabriolet?
The most efficient configuration returns around 29 mpg (UK) combined, or 24 mpg on the US EPA cycle. Across all configurations the UK combined figure runs from 28 to 29 mpg.
How much does the 2018 Porsche 911 Carrera S Cabriolet cost to fuel per year?
The US EPA estimates about $3,400 a year in fuel for the most efficient configuration, based on 15,000 miles of mixed driving and national average fuel prices. Your own cost will depend on mileage and local prices.
Does the 2018 Porsche 911 Carrera S Cabriolet have any recalls?
NHTSA lists no safety recall campaigns for the 2018 Porsche 911 Carrera S Cabriolet as of 6 October 2026. Recalls can be issued years after a model is sold, so it is still worth checking your own VIN.
What are the most common problems reported for the 2018 Porsche 911 Carrera S Cabriolet?
Among the 1 owner complaints filed with NHTSA, the most-reported areas are Electrical system (1 complaint). Complaints are unverified owner reports, not confirmed defects, and raw counts rise with how many cars were sold.
How much interior and luggage space does the 2018 Porsche 911 Carrera S Cabriolet have?
EPA measures interior passenger volume at 68 cubic feet (about 1,926 litres) and luggage volume at 5 cubic feet (about 142 litres). These are US EPA interior-volume figures, which are measured differently from the UK boot-capacity numbers manufacturers quote.
Is the Porsche 911 Carrera S Cabriolet's fuel economy good for a coupe?
Yes — it returns around 29 mpg (UK) combined, against a same-body-style average of roughly 25 mpg among the coupes we track, making it one of the more efficient options in its class.