Why we publish almost no cross-reference numbers
Converter tools return a size family, not an equivalent. We publish a Fram or Wix number on about 3% of our vehicles, and here is the error we found in our own data that explains why.
What Is My Oil Filter?
OEM oil filter lookup
Blog
Reviews, deep dives, and product news on oil filters, motor oil, and vehicle maintenance.
Your oil filter is shared with two dozen other cars. Your oil isn't.
149 filter part numbers cover every vehicle we list. One of them fits 27 models across two makes — and the cars sharing it do not share an oil grade.
The Chrysler, Dodge, Jeep and Ram oil grades that quietly changed
Four Mopar engines were specified on one oil early in their lives and a different one later. Here are the model years where each changed, straight from FCA's own owner's manuals.
Cartridge or spin-on? Why the answer isn't about your car's age
Cartridge filters aren't simply 'the new way'. In our data the split is 901 spin-on to 599 cartridge, and some cars offer both in the same model year depending on which engine they left the factory with.
0W-20, 5W-30, 0W-16: what the numbers mean and why yours is not a suggestion
The two numbers on a bottle describe two different things, and only one of them is about how thick the oil is when your engine is running. Here is what each part means, with the grades our data actually shows.
How often, really? Oil-life monitors, fixed intervals, and severe service
Most new cars no longer have a mileage-based oil change interval at all. Here is what the monitors actually measure, what the published maximums are, and how to tell whether your driving counts as severe.
Welcome to the What Is My Oil Filter blog
What we'll publish here: filter teardowns, explainers on grades and intervals, and notes on when OEM part numbers change mid-year.