Jeep Wrangler: TECHNICAL SPECIFICATIONS / FLUID CAPACITIES

Biodiesel Fuel Requirements

A maximum blend of 5% biodiesel meeting ASTM specification D975 is recommended for use with your diesel engine. If frequent operation with Biodiesel blends that are between 6% and 20% (B6–B20) is desired, the maintenance schedule is subject to shorter intervals...

ENGINE FLUIDS AND LUBRICANTS

CAUTION! Mixing of engine coolant (antifreeze) other than specified Organic Additive Technology (OAT) engine coolant (antifreeze), may result in engine damage and may decrease corrosion protection...

Other information:

Jeep Wrangler 2018-2026 Owners Manual: Cooling System Notes

NOTE: When the vehicle is stopped after a few miles/ kilometers of operation, you may observe vapor coming from the front of the engine compartment. This is normally a result of moisture from rain, snow, or high humidity accumulating on the radiator and being vaporized when the thermostat opens, allowing hot engine coolant (antifreeze) to enter the radiator...

Jeep Wrangler 2018-2026 Owners Manual: FUEL REQUIREMENTS — GASOLINE ENGINE

While operating on gasoline with the required octane number, hearing a light knocking sound from the engine is not a cause for concern. However, if the engine is heard making a heavy knocking sound, see a dealer immediately. Use of gasoline with an octane number lower than recommended octane can cause engine failure and may void the New Vehicle Limited Warranty...