What is the compression ratio of the Lexus IS 350?
The Lexus IS 350 uses a 3.5-liter V6 with a compression ratio generally around 11.8:1, with variations depending on the generation and market (roughly 11.6:1 to 12.3:1 across different engine variants).
Understanding compression ratio
The compression ratio is the mathematical relationship between the volume of air-fuel mix in a cylinder when the piston is bottom dead center and the volume after compression at top dead center. It influences both power and efficiency, as well as how the engine tolerates fuel grades and knock. In the IS 350, the ratio reflects two generations of the 3.5-liter V6 family and the use of direct injection in later variants.
IS 350 engine generations and their compression ratios
The IS 350 has used two main variants of the 3.5-liter V6 over its history. Variations in compression ratio arise from the engine family (older non-direct-injected versus newer direct-injected designs) and regional calibration. The following figures summarize typical ranges associated with those engines.
- 2GR-FSE (earlier 3.5L V6 variants): approximately 11.6–11.8:1
- 2GR-FKS (direct-injected 3.5L V6 variants): approximately 12.0–12.3:1
Exact figures can vary by model year, market, and vehicle specifications. For a precise value, consult the engine specification sheet for your VIN or the official Lexus technical documentation.
Why the numbers matter
A higher compression ratio can improve thermal efficiency and power potential but may require higher-octane fuel to prevent knocking. The IS 350’s shift from non-direct-injection to direct-injection variants typically correlates with modest adjustments to the compression ratio, aligning performance with emissions and fuel economy targets for different generations.
Summary
In short, the Lexus IS 350’s compression ratio sits in a narrow band around 11.6–12.3:1, with commonly cited figures near 11.8:1 for older, non-direct-injected versions and closer to 12.0–12.3:1 for newer direct-injected variants. For the exact number on a specific car, refer to the official Lexus specifications for that VIN.
