Methodology
How our calculators work, what data we use, and the limitations you should know about.
Last updated: February 2026
Overview
AutoSpecs Daily provides 40+ free automotive calculators covering car payments, affordability, insurance estimates, fuel costs, depreciation, and more. This page explains what data sources we use, how our calculations work, and important limitations to be aware of.
Important: All calculator results are estimates. They are not financial advice, insurance quotes, or binding offers. Actual costs will vary based on your specific circumstances, location, credit history, and other factors. Always consult with qualified professionals for important financial decisions.
Data Sources
Our calculators and guides rely on the following publicly available data sources:
Vehicle Fuel Economy
Source: U.S. Environmental Protection Agency (EPA) — https://fueleconomy.gov
MPG ratings for city, highway, and combined driving. Used in our fuel cost, electric vs. gas, and city vs. highway comparison tools.
Vehicle Safety Data
Source: National Highway Traffic Safety Administration (NHTSA) — https://nhtsa.gov
Safety ratings, recall information, and crash test data referenced in our buying guides.
Loan & Payment Calculations
Source: Standard Amortization Formulas
Our payment, affordability, and loan calculators use standard financial amortization formulas. Interest rates are user-inputted, not sourced from specific lenders.
Insurance Estimates
Source: Industry Averages & State Minimums
Insurance calculators use national and state-level average premium data from published industry reports. These are estimates only — actual premiums depend on your driving record, credit score, coverage choices, and insurer.
Depreciation Models
Source: Historical Market Data
Our depreciation calculators use standard depreciation curves based on historical vehicle resale data. Actual depreciation varies by make, model, condition, mileage, and market conditions.
Vehicle Pricing
Source: Manufacturer MSRPs & Market Listings
Pricing referenced in our guides comes from manufacturer suggested retail prices and publicly available market listing data. Prices change frequently and vary by region.
Calculator Accuracy & Limitations
Our calculators are designed to provide useful estimates to help you plan and compare options. They have inherent limitations:
- - Loan calculators assume fixed interest rates and standard amortization. They do not account for variable rates, balloon payments (unless using our balloon payment calculator), or lender-specific fees.
- - Insurance calculators provide rough estimates based on averages. Your actual premium will differ based on your profile, history, and chosen insurer.
- - Fuel cost calculators use EPA-rated MPG, which may differ from your real-world driving conditions.
- - Depreciation calculators use general curves and cannot predict market anomalies or model-specific trends.
- - All calculators are educational tools, not financial advice. Consult with qualified professionals before making major financial decisions.
Buying Guide Research
Our buying guides are researched using the following approach:
- 1Market data review: We analyze current listing prices and availability for vehicles we recommend.
- 2Reliability research: We reference published reliability data, common failure points, and owner feedback from automotive communities.
- 3Specification verification: Vehicle specs (MPG, dimensions, features) are verified against manufacturer data.
- 4Honest limitations: We note when we are relying on estimates, averages, or data that may not reflect your specific situation.
How We Keep Data Current
We review and update our data sources regularly. Calculator formulas are reviewed when industry standards change. Buying guides are updated when model years change, pricing shifts significantly, or new reliability data becomes available. Each piece of content shows its last-updated date so you can assess its currency.
Questions About Our Methodology?
If you have questions about how a specific calculator works or what data sources we use, please contact us.
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