What This Calculator Is Really Estimating
Car wear and tear has two sides: financial wear and mechanical wear. Financial wear is mostly depreciation. Mechanical wear includes tires, brakes, engine usage, corrosion exposure, and maintenance habits.
Current Value vs Depreciation
The old version displayed “depreciation,” but the formula actually returned estimated remaining value. This version separates the two:
This is clearer because a car bought for 25,000 and estimated at 12,000 has depreciated by 13,000.
Why Mileage Unit Conversion Matters
The calculator uses mile-based wear benchmarks internally. If you enter kilometers, the value must be converted to miles:
The old version multiplied kilometers by 1.60934, which made the mileage too high and inflated wear estimates.
Wear Categories
| Category | What it represents | Main influences |
|---|---|---|
| Depreciation | Estimated loss in financial value. | Age, mileage, vehicle type. |
| Maintenance reserve | Planning amount for annual repairs and service. | Vehicle type, mileage, road conditions, maintenance habits. |
| Tire wear | Approximate tire life used. | Mileage, road type, alignment, driving style. |
| Brake wear | Approximate brake service life used. | City driving, hills, towing, driving style. |
| Engine wear | Rough usage-based engine-life estimate. | Mileage, age, oil changes, heat cycles, maintenance. |
Common Mistakes
- Using vehicle age alone and ignoring mileage.
- Using mileage alone and ignoring maintenance history.
- Assuming a percentage score proves the actual mechanical condition.
- Ignoring corrosion from salted roads.
- Forgetting that city driving can wear brakes faster than highway driving.
- Comparing luxury and economy cars with the same maintenance-cost assumptions.
When to Be Careful With the Result
The estimate becomes less reliable for vehicles with accident history, engine swaps, major repairs, extremely high mileage, track use, towing use, flood damage, rust, or incomplete maintenance records.
Frequently Asked Questions
Is this a real car appraisal?
No. It is a simplified educational estimate. Real appraisal depends on make, model, trim, market demand, damage history, options, region, and inspection condition.
Why does road type affect wear?
City driving increases braking and heat cycles. Rough roads and off-road use can increase suspension, tire, and underbody wear.
Why do salted roads matter?
Salt exposure can accelerate corrosion on body panels, brake lines, suspension parts, fasteners, and underbody components.
Why does maintenance routine affect engine wear?
Delayed oil changes, filter changes, coolant service, and other maintenance can increase wear and reduce long-term reliability.