What Is the LML Duramax Turbo? Applications & Specs
The LML is the 2011–2016 6.6L Duramax, and it was the first Duramax generation to pair a variable-geometry turbo with a full SCR (DEF) emissions system.
Quick answer: The LML factory turbo is a Garrett-sourced variable-geometry turbocharger (VGT), commonly cited around 397 hp and 765 lb-ft from the factory. It uses the same vane-and-actuator operating principle as the later L5P/L5D turbo, just on an earlier, smaller-frame platform.
Applications
The LML VGT is the factory turbo on 2011–2016 6.6L Duramax engines in Chevrolet Silverado HD and GMC Sierra HD trucks. True North Turbos builds a 63.5mm drop-in replacement that covers the full range, supporting up to 700WHP.
How the variable geometry works
Like other VGT-equipped diesels, the LML turbo uses a ring of pivoting vanes instead of a wastegate. An electronic actuator adjusts vane angle to control boost and exhaust braking — closing them for quick spool and strong low-end torque, opening them to flow more air at higher load.
What changed from earlier Duramax generations
The LML introduced a full SCR/DEF emissions system alongside the DPF carried over from the LMM, and is generally regarded as having a stronger factory bottom end than the earlier LLY/LBZ/LMM engines. See LML vs LLY/LBZ/LMM for the full comparison.
Known weak points
- Vane sticking from carbon/soot build-up, the same VGT wear pattern seen on later Duramax turbos.
- Actuator wear over high mileage.
Covered in more depth in LML Duramax Turbo Problems.
Frequently asked questions
What years does the LML cover?
2011–2016 model year Chevrolet/GMC 6.6L Duramax trucks.
Is the LML turbo a VGT?
Yes, a Garrett-sourced variable-geometry turbo using an electronic actuator, similar in principle to the later L5P/L5D turbo.
Can the LML turbo be upgraded?
Yes — True North Turbos' 63.5mm drop-in supports up to 700WHP while retaining a direct-fit installation.