Keeping a High-Mileage 6.7 Cummins Alive: What to Check at 50K, 100K, 150K and 200K Miles Category News A 6.7L Cummins with 150,000 miles is not automatically worn out. In fact, many owners keep these engines working well beyond 200,000 miles. What matters more is what happened during those miles: towing, idle hours, fuel quality, oil... By Car Division, 8 October, 2026