WESTERN STAR 4900
PowerObserved trucks and fleets, single-power-unit inspection outcomes, and failure groups grounded in the federal CFR section and BASIC reference.
Interpretation guardrail
These roadside results reflect operators' maintenance and duty cycle as much as the vehicle. They are not evidence of a manufacturer defect. OOS rates and failure frequencies are normalized per inspection, never presented as a raw count pretending to be a rate.
Violation detail is as of Oct 7, 2026; it is not current. Platform and cab labels appear only where external evidence established them. A missing label means “not established,” never “no.”
Observed model footprint
Attributed inspection span: Jun 12, 2023 – Oct 3, 2026.
Reported trucks sum FMCSA truck_units across distinct observed fleets after the existing plausibility clamp. It is operator context, not this model's production count, and never uses power_units or MCS-150 mileage.
Level-scoped OOS outcomes
Rates count OOS inspections only inside the same inspection-level population used by their denominator.
Top violation groups
Attributable vehicle violations grouped only by CFR section and BASIC category as of Oct 7, 2026. Frequencies are per 100 attributed inspections.
CFR 393.9 · Vehicle Maintenance: 9,906 violations; 1,225 marked OOS.
CFR 392.2 · Unsafe Driving: 7,007 violations; 47 marked OOS.
CFR 393.75 · Vehicle Maintenance: 4,362 violations; 2,763 marked OOS.
CFR 393.45 · Vehicle Maintenance: 3,618 violations; 887 marked OOS.
CFR 393 · Vehicle Maintenance: 3,416 violations; 1,884 marked OOS.
CFR 396.17 · Vehicle Maintenance: 3,111 violations; 1 marked OOS.
CFR 393.11 · Vehicle Maintenance: 2,697 violations; 74 marked OOS.
CFR 393.47 · Vehicle Maintenance: 2,527 violations; 151 marked OOS.
CFR 396.3 · Vehicle Maintenance: 2,151 violations; 1,252 marked OOS.
CFR 393.55 · Vehicle Maintenance: 2,122 violations; 1 marked OOS.
Established platform and cab splits
Only externally sourced labels are listed; the model rollup above still includes VINs whose labels are not established.
No platform or cab label is established for this model. That does not mean the model has no platform variants or cab configurations; it means this store has no sourced label to publish.