AT4X Off-Road Lifted Suspension Package, 2" factory lift, Multimatic DSSV dampers and jounce control dampers

Years 2023–27 Models 3 Factory citations 13

Also described as Suspension, off-road, with 1.5 inch liftSuspension, off-road, with 2 inch factory lift and Multimatic DSSV dampers

Also documented for Chevrolet

Documented applications

Sierra 1500 — Next-Generation (2027)

2027 Factory-verified

Pro, Elevation, AT4, Denali, Denali Ultimate: not offered; AT4X: included in the trim group

GM factory document — 2027 gmc next generation sierra 1500 retail and fleet fleet order guide, p.24.
GM factory document — 2027 gmc next generation sierra 1500 retail and fleet fleet order guide rpo codes, p.1.

Sierra HD — T1XX (2020–2027)

2024–2027 Factory-verified

only in: 2500 HD; AT4X; front lift with control arms, ball joints, knuckles and DSSV dampers, rear lift with spacer block, DSSV dampers, half shafts and 3-stage leaf springs from the 3500; 2024: GM Authority 2024 changes page (factory-installed 1.5 inch lift); AT4X: S; Pro, SLE, SLT, AT4, Denali, Denali Ultimate: not offered

GM factory document — 2025 gmc sierra 2500 hd retail and fleet fleet order guide rpo codes, p.1.
GM factory document — 2026 gmc sierra 2500 hd retail and fleet fleet order guide rpo codes, p.1.
GM factory document — 2027 gmc sierra 2500 hd retail and fleet fleet order guide rpo codes, p.1.
GM factory document — 2025 gmc sierra 2500 hd retail and fleet fleet order guide, p.12.
GM factory document — 2026 gmc sierra 2500 hd retail and fleet fleet order guide, p.11.
GM factory document — 2027 gmc sierra 2500 hd retail and fleet fleet order guide, p.9.

Sierra — T1XX (2019–2026)

2023–2026 Factory-verified

the upfitter lists read "Chassis package, high performance lifted"

GM factory document — 2023 gmc 23 sierra 1500 electrical body builder sm en us 2022oct12, p.16.
GM factory document — 2024 gmc 24 sierra 1500 sm electrical body builder esid 23dec12, p.19.
GM factory document — 2025 gmc my25 sierra 1500 electrical bbm, p.17.
GM factory document — 2025 gmc sierra 1500 retail and fleet fleet order guide rpo codes, p.1.
GM factory document — 2026 gmc sierra 1500 retail and fleet fleet order guide rpo codes, p.1.

This page aggregates every documented appearance of ZRX in the GMC reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.