How to Budget for Truck Maintenance Per Mile

Repairs don't show up on a schedule, but the money for them can. A maintenance budget turns every future brake job, clutch, and overhaul into a small cost per mile that you set aside as you go. Then the big bill is a withdrawal, not an emergency.

The idea: every repair has a per-mile cost

Item cost per mile = what the job costs ÷ miles between jobs.

A $2,500 brake job every 250,000 miles costs you $0.010 a mile. You don't pay it that way, since you pay all $2,500 on one day. But the truck uses up a cent of brakes every mile it runs. Add every item together and you have what upkeep really costs per mile.

Reserve per mile = sum of all items per mile + an allowance for unplanned repairs.
Monthly reserve = reserve per mile × miles you run in a month.

Build your list

Start with the work you know is coming. For each item, write down the cost and how many miles apart it happens.

• PM service: oil, filters, grease, and inspection
• Brakes and drums
• Clutch
• DPF cleaning and other aftertreatment work
• Injectors
• Coolant, belts, and hoses
• An engine overhaul fund
• Anything else your truck has: APU, reefer unit, trailer brakes, and so on

For costs, use your shop's quotes or your own invoices. For intervals, use your engine and component makers' recommended service intervals and your own records. Every truck, duty cycle, and route is different, so a number from someone else's truck is only a guess for yours.

Then add an unplanned allowance, a few cents a mile for breakdowns, road calls, tows, and parts that fail early. Look at the last year or two of your unplanned repair bills and divide by miles to set it.

Worked example

These costs and intervals are made up to show the math. Replace them with your own.

• PM service: $450 every 25,000 mi = $0.0180/mi
• Brakes and drums: $2,500 every 250,000 mi = $0.0100/mi
• Clutch: $3,000 every 500,000 mi = $0.0060/mi
• DPF cleaning / aftertreatment: $900 every 200,000 mi = $0.0045/mi
• Injectors: $4,000 every 500,000 mi = $0.0080/mi
• Coolant, belts, hoses: $800 every 150,000 mi = $0.0053/mi
• Engine overhaul fund: $30,000 every 800,000 mi = $0.0375/mi

The planned items add up to about $0.089 a mile. Add an unplanned allowance of $0.05 a mile, and the reserve is about $0.139 a mile.

At 10,000 miles a month, that's $0.139 × 10,000 = about $1,393 a month, or about $16,720 a year. Move that into a separate account every month and don't touch it for anything else.

Notice the overhaul fund is the biggest single line. It's also the one people most often skip, because it's years away. Skipping it doesn't make it cheaper. It just means the money won't be there when you need it.

Check it against what you actually spent

If you've had the truck a while, there's a quicker way: last 12 months of maintenance and repair bills ÷ miles run in the same 12 months. If you spent $18,000 over 120,000 miles, that's $0.150 a mile.

That's your real number, but it only knows about the past. A truck that just had a big job will look cheap until the next one comes due, and an aging truck usually costs more each year. Run both methods and budget with the higher one.

Keep records, because you have to anyway

Federal rules require motor carriers to systematically inspect, repair, and maintain the vehicles they control, and to keep records for each vehicle. Those records show the nature and due date of inspection and maintenance work, plus the date and nature of repairs done. The records must be kept for a year, and for six months after the vehicle leaves the carrier's control (49 CFR 396.3). Each vehicle also needs a periodic inspection at least once every 12 months, with proof of it on the vehicle (49 CFR 396.17).

Those same records are what make your maintenance budget accurate. Log the date, mileage, work done, and cost of every job. After a year, you'll have real intervals and real costs for your own truck.

Put the number to work

• Build your list in the truck maintenance cost per mile calculator.
• Tires are a separate reserve. Work them out with the tire cost per mile calculator.
• Put your maintenance reserve into the cost per mile calculator so every rate you accept pays for the repairs it causes.

Update the reserve whenever you get new quotes, change trucks, or your miles change a lot.