Diesel vs Gas Truck Cost Comparison
Quick answer: A diesel truck pays for its purchase premium only if its yearly fuel saving covers the premium before you sell it. For example, driving 15,000 miles a year: a 22-mpg diesel at $3.80/gal costs $2,590.91/year in fuel vs $3,000.00/year for a 17-mpg gas truck at $3.40/gal — a $409.09 yearly saving, so an $8,000 diesel premium breaks even in about 19.6 years.
Is the diesel engine upgrade worth it? Enter your annual mileage, each truck's fuel economy and your local fuel prices, and this diesel vs gas truck cost comparison shows the annual fuel costs, yearly saving, and how many years until the diesel breaks even.
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Your results
Estimate only. Fuel prices change constantly — enter your current local prices. Resale value is not included.
How to use this calculator
Enter how many miles you drive per year, each truck's fuel economy in mpg, and your local diesel and gasoline prices per gallon. Add the diesel's purchase premium (what the diesel engine option costs over the gas version), any extra yearly DEF and maintenance cost, and how long you plan to keep the truck. Everything recalculates instantly.
How it works
Annual fuel cost = annual miles ÷ mpg × price per gallon, for each truck. Annual fuel saving = gas annual fuel cost − diesel annual fuel cost − extra DEF/maintenance. Break-even years = diesel purchase premium ÷ annual fuel saving. If the annual saving is zero or negative, the diesel never breaks even at your inputs. Total cost over N years: diesel = premium + N × (diesel fuel + DEF/maintenance extra); gas = N × gas fuel.
Worked example
15,000 miles/year; diesel 22 mpg at $3.80/gal → 15,000 ÷ 22 × 3.80 = $2,590.91/year; gas 17 mpg at $3.40/gal → 15,000 ÷ 17 × 3.40 = $3,000.00/year; fuel saving = $409.09/year. With an $8,000 diesel premium and no DEF/maintenance delta, break-even = 8,000 ÷ 409.09 ≈ 19.6 years.
Reference data
This tool consumes no external data table. Diesel and gasoline prices are pump prices that change constantly, so every fuel price in this calculator is a user input — no static price table is embedded, and no current or "average" pump price is claimed here.
Method & sources
Method: break-even years = premium ÷ (gas fuel/yr − diesel fuel/yr − DEF/maintenance extra/yr); totals computed over the user-entered ownership period. All prices and mileage are user-entered. Resale value is excluded as stated above.
- Fuel prices, mileage, fuel economy, premium, DEF/maintenance — all user-entered (no external source).
Frequently asked questions
How is the diesel truck break-even point calculated?
Break-even years = diesel purchase premium ÷ annual fuel saving, where the annual fuel saving = gas annual fuel cost − diesel annual fuel cost − extra DEF/maintenance. With an $8,000 premium and $409.09 of yearly fuel saving, break-even is about 19.6 years.
Why are there no default fuel prices in the calculator?
Pump prices change constantly, so no static price table is used. Enter your current local diesel and gasoline prices per gallon for a comparison that matches what you would actually pay.
What is included in the DEF and maintenance extra cost?
That input is the extra yearly cost of diesel exhaust fluid (DEF) plus any extra scheduled maintenance a diesel truck has over a gas truck, entered as a single annual dollar figure. Leave it at zero if you do not want to count it.
When does a diesel truck never break even?
If the annual fuel saving is zero or negative — the diesel's fuel cost plus DEF/maintenance is not cheaper than gas — the calculator reports that the diesel never breaks even at your inputs.
Does this comparison include resale value?
No. The comparison covers the purchase premium, fuel, and DEF/maintenance extra over your ownership years. Resale value can shift the math, but it is not included because it varies too much to model generically.