The Gladiator's 3.6L Pentastar V6 requires full synthetic oil — 0W-20 is the factory spec. Using the correct viscosity matters more than the brand; using conventional oil in this engine is a mistake.
The 3.6L Pentastar powers every JT Gladiator. It's a robust, well-proven engine with one known sensitivity: it requires full synthetic oil at all times. The tight tolerances in the Pentastar's variable valve timing (VVT) system are designed around synthetic oil's viscosity characteristics — conventional oil doesn't flow fast enough at cold start to properly lubricate the VVT actuators, and degraded synthetic causes sludging in the VVT passages more readily than the spec'd fluid.
Jeep's oil life monitor (OLM) uses engine parameters (temperature cycles, idling time, load) to estimate when the oil should be changed. For most drivers, this works out to roughly 7,000–10,000 miles between changes. For a Gladiator doing heavy trail work with sustained low-speed high-load operation, pull the interval in to 5,000–7,500 miles — the OLM doesn't fully account for trail-use abuse.
**Oil capacity:** 5.9 quarts with filter change. Have 6 quarts on hand — drain capacity varies slightly by how long the oil drains.
**Oil filter:** The Pentastar uses a cartridge-style oil filter (not a spin-on canister). The housing is on the front of the engine, passenger side, accessible from above with a 13/16" socket or the Mopar filter cap tool (PN: 4884899AC). Mopar's OEM filter fits correctly; WIX 57356, Fram Ultra XG10575, and Purolator Boss PBL14621 are compatible aftermarket alternatives.
Mobil 1 0W-20 (5 qt jug): ~$30–35. Industry-standard quality at a reasonable price.
Mopar OEM filter: ~$12–16 at the dealer or through online Mopar parts suppliers. The correct specification, not worth compromising on.
Full DIY kit (6 qt oil + OEM filter + new drain plug washer): ~$50–55. A dealer oil change on a JT typically runs $75–100 depending on location. DIY saves $25–50 per interval.
| Part | Vendor | Est. price |
|---|---|---|
| Mopar Oil Filter — PN 4884899AC (fits 3.6L JT) | Mopar | ~$14 |
| Mobil 1 0W-20 Advanced Full Synthetic (5 qt jug) | Mobil 1 | ~$32 |
| Pennzoil Platinum 0W-20 Full Synthetic (5 qt) | Pennzoil | ~$28 |
| Castrol Edge 0W-20 Full Synthetic (5 qt) | Castrol | ~$29 |
Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.