Total Complaints
1 filings
GMC B6 MEDIUM DUTY · model year
1991 GMC B6 MEDIUM DUTY
1 NHTSA complaints for this specific cohort.
NHTSA overall rating
Not crash-tested
New Car Assessment Program
The 1991GMCB6 MEDIUM DUTY carries 1 consumer safety complaint in NHTSA's Office of Defects Investigation database for this specific model-year cohort. Within that volume, owners reported 0 crashes, 0 fires, 0 injuries, and 0 fatalities. No NCAP 5-star crash-test rating is available for this model year in the federal database.
Component-level analysis is where model-year complaints become actionable: the top complaint category for the 1991 B6 MEDIUM DUTY is engine and engine cooling:engine with 1 filings. Concentration in one or two component groups is the classic signature of a systemic defect; a flat distribution usually reflects normal aging, warranty complaints, or isolated build-plant variability.
NHTSA currently has 2 investigation files overlapping the 1991 B6 MEDIUM DUTY. Owners comparing this cohort against neighboring years should pair the counters above with the complaint-by-year trend on the parent model page — a spike in a single year often tracks to a platform refresh, a new transmission supplier, or an updated ECU calibration. Use the related-complaint feed below to read raw owner narratives before deciding whether any pattern here affects your specific use case.
1
Complaints
0
Crashes
0
Fires
0
Injuries
0
Deaths
Crashes Reported
0 reports
Source
NHTSA ODI
Federal complaints database
Complaints vs. fleet median (215)
At or below the fleet median complaint volume.
Complaints by Component
| Component | Count |
|---|---|
| ENGINE AND ENGINE COOLING:ENGINE | 1 |
Recent Complaints
20030409ENGINE AND ENGINE COOLING:ENGINE
THE VEHICLE EXPERIENCED ENGINE FAILURE FOR THE SECOND TIME. HE STATED THAT THE FIRST TIME WAS 11/99. THE ENGINE HAD 118,000 MILES. HE STATES HE ASKED THE MANUFACTURER FOR ASSISTANCE AND THEY DECLINED BECAUSE OF A TECHNICALITY. HE ALSO STATED THAT THE MANUFACTURE SHOULD REPLACE HIS ENGINE BECAUSE HE SAID THAT WHEN HIS ORIGINAL ENGINE WAS REPLACE THE MECHANIC USED PARTS FROM THE OLD ENGINE. *NLM
Compare 1991GMCB6 MEDIUM DUTY to Similar Vehicles
NHTSA Investigations
Frequently Asked Questions
How many complaints does the 1991 GMC B6 MEDIUM DUTY have?▼
The 1991 GMC B6 MEDIUM DUTY has 1 NHTSA complaints, 0 crashes, 0 fires, 0 injuries, and 0 deaths reported.
What are the most common problems with the 1991 GMC B6 MEDIUM DUTY?▼
The most-complained component for the 1991 GMC B6 MEDIUM DUTY is ENGINE AND ENGINE COOLING:ENGINE with 1 complaints. Other frequently reported areas include various components.
Is the 1991 GMC B6 MEDIUM DUTY safe to buy?▼
Review the complaint history, crash and fire reports, safety ratings, and recall status on this page to make an informed decision. No NHTSA crash test rating is available for this model year. Compare with other model years using the links above.
Where does this data come from?▼
All complaint, recall, and safety rating data is sourced from the National Highway Traffic Safety Administration (NHTSA). Complaints are filed by vehicle owners through NHTSA's Office of Defects Investigation.
Vehicle Safety Guides
Data as of 2025. Sources: NHTSA Office of Defects Investigation (ODI) complaints database, NHTSA recall campaign API, NHTSA NCAP crash-test ratings, and NHTSA FARS for fatality cross-reference.
Read our methodology — how this data is sourced, computed, and verified.