Calculator
Keep or Replace My Car Calculator — Fix or Buy New?
The DriveCost keep or replace calculator evaluates the financial tradeoff between repairing your current car versus buying a replacement vehicle. By adding your estimated repair quote to your current vehicle's future running costs and comparing that sum against the net purchase price (price minus trade-in) and running costs of a replacement, the tool provides a clear break-even answer. In over 70% of cases, paying a $1,500 to $3,000 repair bill is significantly cheaper than taking on a new car payment and elevated insurance premiums.
How the Keep vs. Replace Decision Framework Works
When faced with a major repair bill — such as a blown head gasket, failed transmission, or air conditioning overhaul — drivers often react emotionally. A $2,500 repair bill feels like "throwing money into a money pit." However, from a strictly financial standpoint, past money spent on your car is a sunk cost and should be ignored. What matters is future cash outlay:
Path A (Keep & Repair): Future Cost = Immediate Repair Bill + (Current Car Energy + Maint) × Years
Path B (Replace Vehicle): Future Cost = (Replacement Purchase Price − Trade-in Value) + (Replacement Energy + Maint) × Years
The 50% Rule of Thumb for Vehicle Repairs
Automotive financial advisors often use the 50% Rule: If an estimated repair costs more than 50% of the vehicle's current resale value, or if total annual repairs exceed the sum of 12 months of new car payments, replacing the vehicle may be justified.
| Scenario Parameter | Path A: Repair Current Car | Path B: Buy Replacement SUV |
|---|---|---|
| Current Vehicle / Target | 2015 Midsize Sedan (110k mi) | 2024 Compact SUV (New) |
| Upfront Cash Required | $2,200 (Transmission repair) | $26,000 ($32k MSRP − $6k trade-in) |
| Annual Energy (15k mi/yr) | $1,980 (25 MPG gas) | $1,320 (37 MPG hybrid) |
| Annual Maintenance & Tires | $1,050 / year | $580 / year |
| Annual Insurance & Tax Difference | $1,100 / year | $1,750 / year (Higher value) |
| 3-Year Total Cash Outlay | $14,590 | $36,950 |
In this example, keeping and repairing your 2015 sedan saves over $22,000 over 3 years compared to buying a new vehicle, even though the new hybrid uses less gas and needs less maintenance!
When Replacing Your Car DOES Make Financial Sense
- Catastrophic Structural or Safety Failures: Severe frame rust, compromised airbag systems, or unrepairable electrical harness failures.
- Unreliable Transportation Threatens Income: If frequent breakdowns risk your employment or business, reliability carries financial value beyond repair bills.
- Extremely High Annual Mileage: If you commute 25,000+ miles per year, switching from a 20 MPG older vehicle to a 45 MPG hybrid or EV saves $2,500+ per year in energy, covering replacement costs faster.
Frequently Asked Questions: Keep vs. Replace
DriveCost multiplies your estimated annual gallons by the gasoline price you enter (or the national average). Estimated gallons = annual miles ÷ weighted MPG, where weighted MPG blends the EPA city and highway ratings using your city/highway driving split.
EPA ratings come from standardized lab tests at fueleconomy.gov. They are useful for comparing vehicles, but real-world economy varies with weather, traffic, speed, terrain, vehicle condition and driving style. DriveCost labels them "EPA-rated" and treats them as estimates.
Cost per mile = total annual operating costs ÷ annual miles. Operating costs include fuel or electricity, maintenance, tires and other recurring costs you enter. It excludes the one-time purchase price and depreciation.
Five-year energy cost is the annual energy cost multiplied by your ownership period. The full five-year ownership view also adds estimated maintenance, tires, depreciation and optional insurance/registration, using documented assumptions that are shown on the methodology page.