What is the compression ratio of the BRZ 22?

The compression ratio of the 2022 BRZ is 12.5:1.

This article explains what that number means for performance, why Subaru set it at this level, and how the BRZ's engine compares with its GR86 sibling and other sport cars in its class.

Understanding the compression ratio and its impact

The compression ratio measures the total cylinder volume when the piston is at the bottom of its stroke versus when it is at the top. In a naturally aspirated engine, a higher ratio generally improves thermal efficiency and can boost power output at higher revs, but it also increases the risk of detonation if fuel quality or timing isn’t optimal. The BRZ uses a 2.4-liter FA24D flat-four engine tuned for a lively, driver-focused character without forced induction.

Key effects of a 12.5:1 ratio

The following factors are most affected by this engine tuning:

• Higher thermal efficiency, aiding both performance and fuel efficiency in natural aspiration conditions.


• Strong response at higher revs, aligning with the BRZ’s sport-oriented driving feel.


• Detonation margins depend on fuel octane and engine timing; premium fuel is typically recommended to prevent knock.


• Engine components and intake/exhaust tuning are optimized to maximize power safely at the higher compression.


• Not designed for heavy boost; the 2022 BRZ remains naturally aspirated in its standard configuration.

In short, a 12.5:1 compression ratio helps the BRZ achieve a bright, responsive NA character while maintaining efficiency and reliability, provided fuel and timing are properly managed.

BRZ and GR86: shared engineering

The BRZ and its close cousin, the Toyota GR86, share the same fundamental engine and compression ratio, reflecting a joint approach to the sporty coupe formula. This shared setup emphasizes driver-focused performance without turbocharging in the 2022 models.

To illustrate the connection, here are quick notes about the engine and specs:

• Engine: 2.4-liter FA24D horizontally opposed boxer; naturally aspirated.


• Compression ratio: 12.5:1.


• Power: around 228 horsepower in US BRZ 2022 models, with variations by trim and market.


• Drivetrain: rear-wheel drive; manual and automatic transmissions available in various markets.

These shared figures underscore Subaru and Toyota’s collaboration on the BRZ/GR86 platform, prioritizing driver engagement and predictable, responsive handling over turbocharged output in the current generation.

Summary

The 2022 BRZ uses a 12.5:1 compression ratio on its 2.4-liter FA24D engine, chosen to balance natural aspiration, high-revving character, and efficiency. This ratio is shared with the GR86, reflecting a joint engineering approach that emphasizes driver-focused performance rather than forced induction. For enthusiasts, the result is a lightweight, rear-wheel-drive coupe that rewards precise throttle control and honest, engaging driving dynamics.

Is a BRZ faster than a wrx?

The Subaru WRX is generally faster in a straight line, while the Subaru BRZ is quicker around corners and has better handling due to its lighter weight and rear-wheel drive setup. The WRX has a turbocharged engine with more horsepower, while the BRZ has a naturally aspirated engine. However, the difference can be marginal in some situations, and overall lap times on a road course are often close. 
You can watch this video for a comparison of the WRX and BRZ's performance: 59sBen HardyYouTube · Feb 25, 2023
Subaru WRX

• Engine: Turbocharged 2.4L flat-four engine (271 horsepower) 
• Drivetrain: All-wheel drive 
• Performance: Quicker in a straight line due to more horsepower and torque, providing faster acceleration 
• Handling: Capable, but more focused on a powerful all-around performance, including confidence in various road conditions 

Subaru BRZ

• Engine: Naturally aspirated 2.4L flat-four engine (228 horsepower) 
• Drivetrain: Rear-wheel drive 
• Performance: Less powerful in a straight line, but the lower weight makes it feel agile 
• Handling: More nimble and precise, especially in corners and on twisty roads, thanks to its lightweight, RWD design 

Which one to choose

• Choose the WRX if: You prioritize straight-line speed, all-weather capability, and a more practical sedan with a powerful turbo engine for daily driving. 
• Choose the BRZ if: Your priority is a more traditional sports car feel with sharp handling, balance, and a focus on driver engagement on a winding road. 

How much horsepower does the 22 BRZ have?

The 2022 BRZ features an all-new, larger, 2.4-liter direct-injection SUBARU BOXER engine producing 228 horsepower while delivering a more than 15% increase in torque, at 184 pound-feet.

What year to avoid BRZ?

The Subaru BRZ years to avoid are 2013 and early 2014 due to significant engine issues like valve spring recall problems and potential oil consumption. While there were other recalls and issues in later years (such as a 2018 fuel pump recall), the 2013-early 2014 models are the ones most commonly cited as years to be particularly wary of. 
This video discusses the major problems in early models of BRZ/FRS/86: 58sShifting LanesYouTube · Apr 25, 2018
Years to generally avoid

• 2013 and early 2014: These model years had recalls and reports of significant problems, including:
  • Valve spring recall: An issue where valve springs could fracture, leading to engine failure.
  • Oil issues: Some models, particularly those produced before a certain date, had a tendency for oiling problems.
  • Engine tuning and ECU calibration: Early models had a less optimal engine calibration.
  • Other issues: Users report issues with power windows freezing, water leaks, and interior rattles. 

Other years to be cautious of

• 2018: This year had a fuel pump recall and a recall for the rearview camera not displaying properly.
• 2019: Some 2019 models were included in the 2018 fuel pump recall. 

What to do if buying a used BRZ

• Check for recalls: Before purchasing, use the VIN to check if any recalls have been performed. 
• Be prepared for oil consumption: The BRZ can burn oil, so check the oil level regularly regardless of the model year. 
• Consider newer models: Later model years, such as the 2017 and later, generally have fewer reported issues. 

What is the compression ratio of the GR86 engine?

The Toyota GR86 has a compression ratio of 12.5:1. This high compression ratio is a key factor in the engine's performance and is enabled by the use of both direct and port fuel injection (Toyota's D-4S system) to manage cylinder cooling and efficient combustion. 
You can watch this video to learn more about the GR86's engine, including its compression ratio: 51sTDTVGarageYouTube · Apr 2, 2022

• 12.5:1: The specific compression ratio is 12.5:1. 
• High performance: This ratio is designed to maximize power and efficiency from the naturally aspirated 2.4L boxer engine. 
• D-4S injection: To handle this high ratio, the engine uses a dual-injection system (Toyota's D-4S) which injects fuel both directly into the cylinder and into the port, helping to cool the cylinders and prevent knocking. 
• Premium fuel: The high compression ratio requires the use of premium (higher octane) fuel to avoid engine damage and ensure proper performance, as recommended by the owner's manual.