From old-school gauges to AI-powered assistants, modern car diagnostics blend mechanical know-how with cutting-edge tech. Whether you’re a weekend DIYer or a pro, mastering both tools and process can ...

Julia Kagan is a financial/consumer journalist and former senior editor, personal finance, of Investopedia. Chip Stapleton is a Series 7 and Series 66 license holder, CFA Level 1 exam holder, and ...