Vehicle report
1978 MACK RM400
This model year
What the record shows
The 1978 Mack Rm400 is the 2nd model year of a nameplate NHTSA records from 1977 to 1981.
The federal record holds 22 service bulletins for it.
Counts are reports, not rates. A complaint is something an owner chose to file; it is unverified and unadjusted for how many of these cars were sold, so the useful comparison is against other model years of the same car. Recalls and investigations carry more weight because a manufacturer or regulator acted on them.
Reading this report
Complaint counts are reports filed with NHTSA, not failure rates. A common model collects more of them than a rare one that breaks more often.