Dual-Mode Exhaust, sometimes referred to as active exhaust and by several other terms, is a General Motors technology that enables a vehicle to alter the sound and performance of its exhaust system.
How It Works
The dual-mode exhaust system features electronically-controlled valves that can be in one of two positions: opened and closed. When the valves are closed, exhaust gasses are carried via their typical path through the mufflers. When the valves are open, however, exhaust gasses bypass the mufflers under acceleration for improved performance and greater sound levels.
It’s worth noting that, in some cases, the valves open automatically, regardless of original flap position, when the engine speed reaches or exceeds 3,500 RPM.
Benefits
Dual-mode exhaust carries two primary benefits:
- Sound: more aggressive exhaust note
- Performance: added power or torque due to less exhaust back-pressure, resulting in higher levels of performance
Augmentation
In recent years, GM began to augment the dual-mode exhaust system with sound piped into the cabin, both inductively (from the engine) and digitally (via the vehicle’s speaker system). The latter of these, the digital augmentation via the vehicle’s speaker system, has been tuned to work in conjunction with dual-mode exhaust. This has resulted in the system offering more personalization options, such as a “stealth” mode to a more aggressive “track” mode, in newer implementations of the system.
Also Known As
Though GM typically refers to the feature described here as dual-mode exhaust, it can also be referred to as:
- Active exhaust
- Variable mode exhaust
- Performance variable mode exhaust
- Dynamic exhaust system
- Two-mode exhaust
RPO Identification
A dual-mode exhaust system has traditionally carried the GM RPO code NPP. It’s worth noting that NPP is not an acronym for anything.
Vehicle Applications
GM’s dual-mode exhaust has been or is currently offered on the following vehicles:
Chevrolet
- Camaro
- Fifth-generation (2009 – 2015)
- Optional on SS
- Standard on SS 1LE, ZL1, Z28
- Sixth-generation (2016 – 2024)
- Optional on LT, SS
- Standard on 1LE, ZL1
- Fifth-generation (2009 – 2015)
- Corvette
- Corvette C6
- Corvette C7
- Optional on C7 Stingray
- Standard on Grand Sport, Z06, ZR1
- Corvette C8
- Optional on C8 Stingray and C8 E-Ray
- Standard on C8 Z06, C8 ZR1, C8 Zora
- Silverado 1500 (2024 – present)
- Standard with 6.2L L87 engine
- Tahoe (2024.5 – present)
- Standard with 6.2L L87 engine (expected)
- Suburban (2024.5 – present)
- Standard with 6.2L L87 engine (expected)
Cadillac
- CTS-V
- Second-generation
- Third-generation (2016 – 2020)
- ATS-V
- First-generation (2016 – 2020)
- CT4-V
- CT4-V Blackwing
- CT5-V
- CT5-V Blackwing
- Escalade-V (2023 – present)
- Escalade-V ESV (2023 – present)
Buick
- No current implementations of dual-mode exhaust
GMC
- Sierra 1500 (2024 – present) with 6.2L L87 engine
- Standard with 6.2L L87 engine
- Yukon (2024.5 – present)
- Standard with 6.2L L87 engine (expected)
- Yukon XL (2024.5 – present)
- Standard with 6.2L L87 engine (expected)