With a growing number of Dark Horses hitting their first or second oil change, I've been seeing a lot of confusion in threads here and on other forums — wrong oil viscosity, wrong capacity, and people struggling with the filter. Let's clear it all up in one place.

The right oil: Ford specs 5W-30 full synthetic for the Dark Horse's 5.0L Gen IV Coyote. The OEM filter is the Motorcraft FL-500S. Don't get tripped up by info from older Mustang threads — the standard GT traditionally used 5W-20, but the Dark Horse is rated for 5W-30. Always verify with your owner's manual or the sticker under your hood.

Capacity gotcha — 2024 vs. 2025: The 2024 Dark Horse takes 10 quarts with a filter change. The 2025 model was revised down to 9.5 quarts. Small difference, but overfilling is bad news for any high-revving V8 — measure carefully and check the dipstick after running the engine for a minute to let everything circulate.

The filter access trick: The FL-500S is buried in a tight spot. The easiest DIY method is to turn your wheels to full lock and access the filter through the wheel well opening — no need to remove the splash shield. Use a cap-style filter wrench, not a strap wrench. Takes a couple extra minutes but saves a lot of frustration.

Track day rule: Ford's standard interval is 7,500 miles or 12 months for street driving. But if you're doing any track time, change the oil after every event, full stop. Sustained high-RPM running shears oil viscosity far faster than the intelligent oil-life monitor accounts for. If your oil looks dark brown to black after a track day, it's done.

What's your setup? Running OEM Motorcraft oil and filter, or have you switched to a different full synthetic? And for anyone who's tracked theirs — how often are you changing between events?