OnStar One Fleet, 48 months

Years 2025–27 Models 4 Factory citations 13

Query this via API →

Also described as OnStar One Fleet, 48 months of service

Also documented for Cadillac Chevrolet GMC

Documented applications

Enclave — VSS-S (2025–2027)

2025–2027 Factory-verified

O on all trims; fleet plan; the 2025 guide names it OnStar One Business Plus

GM factory document — 2025 buick all new enclave fleet order guide, p.34.
GM factory document — 2026 buick enclave fleet order guide, p.32.
GM factory document — 2027 buick enclave fleet order guide, p.32.

Encore GX — VSS-F (2020–2027)

2025–2027 Factory-verified

Preferred, Sport Touring, Avenir: O; the 2025 guide names the plan OnStar One Business Plus

GM factory document — 2025 buick encore gx fleet order guide, p.38.
GM factory document — 2026 buick encore gx fleet order guide, p.36.
GM factory document — 2027 buick encore gx fleet order guide, p.34.

Envision — E2XX (2021–2027)

2025–2027 Factory-verified

2027: all trims: O; the 2025 list reads OnStar One Business Plus - 48 Months of Service; the 2026–2027 lists name the plan differently

GM factory document — 2025 buick envision fleet order guide rpo codes, p.1.
GM factory document — 2027 buick envision fleet order guide rpo codes, p.1.
GM factory document — 2027 buick envision fleet order guide, p.27.

Envista — VSS-F (2024–2027)

2025–2026 Factory-verified

all trims: O; the 2025 list calls it OnStar One Business Plus, 48 months of service

GM factory document — 2025 buick envista fleet order guide rpo codes, p.1.
GM factory document — 2025 buick envista fleet order guide, p.27.
GM factory document — 2026 buick envista fleet order guide rpo codes, p.1.
GM factory document — 2026 buick envista fleet order guide, p.26.

This page aggregates every documented appearance of R8Z in the Buick reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.