Parts Advisor Guides
Practical knowledge for the parts counter — clear, concise, and written for people who do the job.
How to Read a VIN Number
Learn what each of the 17 characters means — country codes, manufacturer IDs, check digit validation, model year decode table, and why the last 8 matter most at the parts counter.
Gross Profit vs. Markup Explained
Worked examples showing why 40% margin ≠ 40% markup, a conversion table from 20–50%, reverse calculation formulas, and real-world pricing scenarios for parts advisors.
NATO Phonetic Alphabet Guide
Full alphabet with pronunciation, the 10 most confused letters ranked by frequency, number codes, and tips for learning NATO fast on the job.
How to Read Tire Sizes
What every number on a tire means, the math behind overall diameter, the ±3% replacement rule, plus-sizing and minus-sizing explained, and speedometer impact.