The Link Between Age, Mileage, and Cost-Per-Mile

Fleet data consistently shows that as vehicles accumulate mileage and age, their maintenance costs tend to increase. In a study conducted by Argonne National Laboratory, light-duty gasoline pickups (such as the Ford F-150) experienced M&R costs that started at around $0.06–$0.08 per mile in the first year and rose to $0.30–$0.34 per mile by year 15. This pattern wasn’t limited to pickups—similar trends were observed in SUVs and sedans, with average M&R costs of approximately $0.18 per mile over 150,000 miles.

Deferred vehicle replacement can exacerbate these costs. A fleet audit by the South Florida Water Management District noted that postponing vehicle replacement led to more units meeting replacement criteria each year—along with a steady rise in repair costs.

Heavy-duty fleets aren’t immune either. According to the USDA’s Agricultural Marketing Service, fleets extending truck lifecycles saw repair and maintenance costs hit a record $0.196 per mile in 2022, largely due to deferred replacement and extended service periods. The longer a truck stays in service, the more frequent and expensive its repairs become—further reinforcing the age-mileage-cost connection.

Utilimarc Data Insight: How Age and Mileage Affect Maintenance Costs

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At Utilimarc, we took a closer look at the real-world impact of vehicle age and life-to-date (LTD) mileage on maintenance costs, using data from our client fleets with F-150-equivalent trucks.

The chart below illustrates average maintenance cost per mile (including parts and labor) based on a vehicle’s age and LTD mileage:

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In this heatmap:

• Green cells represent “sweet spots” where maintenance costs are low.
• Red cells indicate higher-cost scenarios—vehicles that are more expensive to operate.

For example, a 4-year-old pickup with 50,000 miles costs about $0.16 per mile to operate. But a 12-year-old truck with just 80,000 miles jumps to $0.37 per mile, despite the lower mileage.

Recognizing Patterns

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Looking across each row (same age, different mileages), the changes are relatively minor. For instance, a 5-year-old vehicle costs $0.20 per mile whether it has 40,000 or 100,000 miles.

In contrast, moving down each column (same mileage, increasing age), costs rise significantly. This suggests:

Age may be a stronger driver of cost-per-mile than mileage.

Why? One reason could be survivor bias—problematic high-cost vehicles often exit the fleet before reaching high mileage. Another reason may be aging components, which become more expensive to maintain over time, regardless of how much the vehicle is driven.

Should It Stay or Should It Go?

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This data challenges a common assumption in fleet management: that low-mileage older vehicles are cheap to keep. In reality, older units—even with low miles—can be more expensive than expected.

That’s why a cost-per-mile strategy, grounded in actual data, is critical to effective lifecycle management. It ensures decisions aren’t made solely on odometer readings, but on the true economics of keeping a vehicle on the road.

Cost Isn’t Always Linear: What the Broader Data Tells Us

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While older, high-mileage vehicles generally cost more to maintain, that doesn’t mean the relationship is perfectly predictable.

Argonne’s analysis also showed that while M&R costs increased steadily up to about 100,000 miles, the curve “flattened between 100,000 and 200,000 miles”. This anomaly is often due to “survivor bias”—vehicles that would incur extremely high repair costs are often retired before those expenses are ever logged.

This creates an illusion that costs plateau at high mileage when, in reality, extreme costs are simply removed from the dataset. It’s a key reason why cost-per-mile metrics based solely on age and miles can underestimate the true cost of keeping aging vehicles in service.

Operating Conditions Matter—A Lot

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Beyond age and mileage, fleet operating conditions are critical to understanding lifecycle costs. A study from West Virginia University highlighted several environmental and operational factors—including region, vehicle usage patterns, and seasonal temperature fluctuations—that significantly affect a vehicle’s duty cycle and corresponding repair costs.

A vehicle driven in stop-and-go urban routes, or used for frequent towing or off-road travel, will likely wear faster and incur higher per-mile costs than a similar vehicle used in steady highway conditions—even if both have the same mileage. Harsh climates, terrain, and aggressive driving cycles can accelerate component wear and lead to inconsistent cost trends across a fleet.

This variability means not all older vehicles are costlier, and not all younger vehicles are cheaper. Well-maintained, lightly-used units may stay cost-effective beyond their expected service life, while others may become burdensome far earlier.

Smart Lifecycle Planning: Balancing Age, Mileage, and Real-World Data

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To control costs, many public and private fleets use structured lifecycle planning. For example:

• The U.S. GSA recommends replacing gas pickups at 7 years or 65,000 miles, and diesel pickups at 8 years or 150,000 miles.
• The Texas Comptroller allows earlier replacement for high-cost vehicles, and extended use for low-cost ones.
• The City of Hamilton tracks over-age assets, highlighting cost and downtime issues in their 2024 Asset Management Plan.

These policies emphasize that replacement decisions shouldn’t rely solely on age or mileage thresholds. Instead, the best strategies evaluate:

• Maintenance cost history
• Utilization rates and reliability
• Total cost of ownership
• Downtime and operational impact

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Final Takeaway

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While age and mileage are helpful indicators, they don’t tell the full story.

Utilimarc’s data and national research both point to a clear conclusion: vehicles become cost-inefficient not just because of how far they’ve driven—but how long they’ve been on the road.

The best fleet strategies combine predictive data, cost-per-mile trends, and practical context to make timely, cost-effective replacement decisions.

If you're ready to take the guesswork out of lifecycle planning, we’re here to help. Contact us to get started.

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