Updated By
The DieselTechWork Team covers pay, career paths, and hiring for diesel and heavy equipment mechanics. Pay and employment figures come from the U.S. Bureau of Labor Statistics Occupational Employment and Wage Statistics program. Living cost comparisons come from Bureau of Economic Analysis regional price data. Statistics about job listings, such as how often listings ask for a CDL, come from listings posted on DieselTechWork.
DieselTechWork earns a commission on some links in this post at no extra cost to you.
Diesel mechanics earn a national median of $61,770 per year. Auto mechanics earn $50,620. That is an $11,150 annual gap, according to BLS May 2025 data (occupation codes 49-3031 and 49-3023). The training timeline is similar for both, but the work, the employers, and the long term trajectory differ. This guide compares them side by side.
Salary Comparison
| Diesel Mechanic | Auto Mechanic | |
|---|---|---|
| BLS Code | 49-3031 | 49-3023 |
| Median Pay | $61,770 | $50,620 |
| Median Hourly | $29.70 | $24.34 |
| Entry Level Pay | $44,500 | $34,660 |
| Top 10% Pay | $88,740 | $81,790 |
| Annual Salary Gap | +$11,150 | Baseline |
For a full breakdown of diesel pay across all 50 states, see our diesel mechanic salary by state guide.
Over a 30 year career, the $11,150 annual gap compounds to over $334,000 in total earnings difference before accounting for raises, overtime, or certification premiums.
Why Diesel Pays More
Three factors drive the gap.
Equipment Value - The vehicles diesel techs work on cost $150,000 to $200,000 new.
System Complexity - Modern diesel engines with DPF, DEF, EGR, and high pressure common rail injection require specialized diagnostic skills. The electronic systems are layered and misdiagnosis is expensive.
Workforce Size - There are roughly 825,800 auto techs in the U.S. versus 316,000 diesel techs, according to BLS 2025 employment estimates. The diesel side has the same shortage problem but a much smaller talent pool. Supply and demand works in diesel techs’ favor.
What You Work On
Diesel - Medium and heavy duty vehicles including semi trucks, delivery trucks, transit buses, school buses, construction equipment, and generators. The components are larger, the parts are heavier, and the work often involves outdoor or large shop bay environments. Many diesel mechanic positions are with fleets, meaning you work on the same vehicle types repeatedly and build deep specialization.
Auto - Passenger cars, SUVs, and light trucks. The vehicle variety is broader since you might see a Honda Civic followed by a Ford F-150 in the same morning. Most auto techs work in dealership service departments or independent repair shops. The individual repair value is typically lower but the volume is higher.
Training And Certifications
Diesel jobs typically require a high school diploma, while auto jobs typically require a postsecondary certificate, according to the Bureau of Labor Statistics. UTI’s automotive program runs 51 weeks and the diesel program runs 45 weeks, according to UTI’s published program lengths.
The certification paths split after training.
Diesel - The ASE T Series (Medium/Heavy Truck) and H Series (Transit Bus) are the standard credentials. Eight tests per series at $62 each, requiring two years of work experience. Master Medium/Heavy Truck Technician requires passing T2 through T8 with active status.
Auto - The ASE A Series (Automobile) covers eight test areas including engine repair, brakes, electrical, and HVAC. Same fee structure and experience requirements as the diesel side. Master Automobile Technician requires passing all eight.
Government fleet mechanic and transit positions almost universally require ASE certification for hiring or advancement, regardless of which side you work on.
Work Environment
Diesel - Larger shop bays or field service. Some truck mechanic roles involve road calls where you drive to a broken down vehicle. Parts are heavier, tools are bigger, and the physical demands are greater. Shift work is common in 24/7 fleet operations.
Auto - Climate controlled bays in most dealerships and chain shops. Standard business hours are more common, though evenings and weekends are typical in retail service. Less heavy lifting on average but more repetitive motion.
Job Outlook
| Diesel Mechanic | Auto Mechanic | |
|---|---|---|
| U.S. Jobs | ~316,000 | ~825,800 |
| Annual Openings | ~24,400 | ~66,200 |
| 10 Year Growth | 4% | 5% |
| Demand Driver | Retirements, fleet expansion | Vehicle complexity, retirements |
Auto has more total openings because the workforce is larger. Diesel has fewer openings but a smaller pool of qualified candidates competing for them. BLS projects approximately 24,400 annual diesel openings and 66,200 annual auto openings, driven primarily by retirements in both fields.
Electric Vehicle Impact - EV adoption is affecting the auto side faster. Passenger EVs require less mechanical maintenance (no oil changes, no transmission fluid, fewer brake replacements from regenerative braking). Class 8 electric trucks exist but represent a small fraction of the commercial fleet.
Career Ceiling
A diesel tech who earns Master Technician status and specializes in diagnostics can reach $80,000 to $90,000+ in high demand markets. Government fleet positions at this level include pensions, full benefits, and overtime. For state by state numbers, see our salary guide.
An auto tech with Master Technician status can reach $65,000 to $80,000 at top dealerships. Some flat rate techs exceed that based on volume. The path to shop foreman, service manager, or independent shop owner is well established but less common on the diesel side.
Browse open diesel mechanic jobs →
Get weekly diesel jobs and salary data →
Frequently Asked Questions
Do Diesel Mechanics Make More Than Auto Mechanics?
Yes. The national median for diesel mechanics is $61,770 per year compared to $50,620 for auto mechanics, a gap of $11,150 based on BLS May 2025 data. The gap is driven by higher equipment value, greater system complexity, and a smaller qualified workforce.
Is It Harder to Become a Diesel Mechanic?
Diesel jobs typically require a high school diploma, while auto jobs typically require a postsecondary certificate, according to the Bureau of Labor Statistics. The technical complexity of diesel work is generally considered higher due to emissions systems, high pressure fuel injection, and heavier components.
Can You Switch From Auto to Diesel?
Many foundational skills transfer including diagnostics, electrical systems, brakes, and HVAC. The main learning curve covers diesel specific systems like high pressure common rail injection, DPF/DEF aftertreatment, and air brake systems. Some employers hire experienced auto techs and train them on diesel equipment. If you're making that move, rebuild your resume around the work that transfers (diagnostics, electrical, brakes, HVAC) so a fleet hiring manager sees the overlap first. PopResume is a resume builder you can use for that.
Are Diesel Mechanics in Higher Demand?
Both are in demand. Auto has more total openings (66,200 per year) because the workforce is larger. Diesel has fewer openings (24,400 per year) but a smaller talent pool. The ratio of openings to qualified candidates tends to favor diesel techs in most markets.
Will Electric Vehicles Replace Diesel Mechanics?
Not in the near term. Class 8 electric trucks represent a small fraction of the commercial fleet. Diesel techs will eventually need to learn hybrid and electric commercial systems, but the occupation is not declining.
Last updated: September 2026. Pay data from BLS OEWS May 2025; jobs and openings from the BLS Occupational Outlook Handbook, 2025 to 2035. Diesel mechanic = 49-3031. Auto mechanic = 49-3023.