What owners learn the hard way, before you buy.
Free calculators for wrenching and modding, and a VIN decoder that pulls recalls straight from NHTSA. For each car generation we also write one sourced report: weak spots, rust, prices, and what to fix in the first 90 days.
Free tools
- VIN Decoder & Recall CheckYear, engine, plant, recalls and complaint count from a VIN.
- Tire Size Calculator & ComparisonCompare two sizes: diameter, sidewall, speedo error.
- Wheel Offset & Fitment CalculatorPoke and inner clearance from width, offset and spacers.
- Gear Ratio & RPM CalculatorSpeed in each gear and cruising RPM.
- 0-60 & Quarter Mile CalculatorEstimate 0-60, ¼-mile ET and trap speed.
- Tire Date Code (DOT) DecoderHow old are those tires? Decode the DOT week/year.
The reports
One report per generation (an NA Miata and an NB Miata are separate reports). Each one covers buying (what to check, what to walk away from, what it should cost) and owning (what breaks, what to fix first, which upgrades are worth it, what fails on track). Every fact is stored with its sources. First up is the NA Miata, in research now.