Learn About Car Fluids

Plain-English guides to the fluids that keep your vehicle running. No jargon, no sales pitch — just the information you need.

Synthetic vs Conventional Oil

What's the actual difference, when does it matter, and is the upgrade worth the extra cost?

What Oil Weight Numbers Mean

0W-20, 5W-30 — what do those numbers mean and why does your car need a specific one?

What Happens If You Use the Wrong Oil?

Used the wrong weight or type? Here's what actually happens, when to worry, and when to relax.

Not Sure What Your Vehicle Needs?

Use our free lookup tool — just pick your year, make, and model.

Find Your Oil Type