2021 Honda Odyssey — Fluid Type & Capacity Specs

Quick reference

Fluid	Type/Spec	Capacity
Engine Oil	0W-20, API SP / Honda HFS-4	5.7 quarts
Engine Coolant	Honda Type 2 Coolant	7.3 US quarts
Transmission Fluid	Honda DW-1 Automatic Trans. Fluid	3.5 quarts (drain/refill)
Brake Fluid	Honda Heavy Duty Brake Fluid DOT 3	As needed
Power Steering	Electric (No Fluid)	N/A
Washer Fluid	Honda Windshield Washer Fluid	0.9 US gallon

Engine Oil

The 2021 Honda Odyssey, equipped with the 3.5L V6 engine, requires 0W-20 engine oil that meets or exceeds the American Petroleum Institute (API) SP classification. Honda also specifies the use of their Honda HFS-4 oil, though any API SP 0W-20 oil is acceptable. The engine oil capacity with a filter change is approximately 5.7 quarts (5.4 liters).

Maintenance Interval: Honda recommends changing the engine oil and filter every 7,500 to 10,000 miles or every 12 months, whichever comes first, under normal driving conditions. This is part of Honda's Maintenance Minder system, which will illuminate a "B1" service code when an oil change is due. For severe driving conditions (e.g., frequent short trips, extreme temperatures, towing), more frequent oil changes may be necessary.

Pitfalls: Always ensure the correct oil viscosity (0W-20) and API SP rating are used. Using a different viscosity can impact fuel economy and engine longevity. Using oil that does not meet API SP standards may not provide adequate protection against low-speed pre-ignition (LSPI), a common issue in modern direct-injection engines.

Engine Coolant

All 2021 Honda Odyssey models utilize Honda Long-Life Antifreeze/Coolant Type 2. This is a silicate-free, OAT (Organic Acid Technology) coolant, identifiable by its blue color. It is pre-mixed and does not require dilution. The total system capacity is approximately 7.3 US quarts.

Maintenance Interval: Honda typically recommends replacing the engine coolant every 120,000 miles or 10 years, then every 60,000 miles or 5 years thereafter. This interval can vary based on driving conditions.

Pitfalls: Never mix Honda Type 2 coolant with other types of coolant (e.g., green conventional, yellow HOAT, or other colors). Mixing different coolant chemistries can lead to compatibility issues, gelling, reduced corrosion protection, and internal engine damage. Always use Honda Type 2 coolant or an equivalent OAT coolant that explicitly states compatibility with Honda vehicles. Do not use tap water for dilution if you are using concentrated coolant; only use distilled water.

Transmission Fluid

The 2021 Honda Odyssey is equipped with a 10-speed automatic transmission that requires Honda DW-1 Automatic Transmission Fluid. The drain and refill capacity is approximately 3.5 quarts (3.3 liters). A full dry fill capacity (e.g., after a transmission overhaul) would be significantly higher, around 7.9-8.4 quarts. For routine maintenance, only a drain and refill is typically performed.

Maintenance Interval: Honda's Maintenance Minder system will indicate when a transmission fluid change is due, typically around 60,000 to 90,000 miles, depending on driving conditions. For vehicles used for towing or in heavy city traffic, more frequent changes may be advisable.

Pitfalls: It is absolutely critical to use only Honda DW-1 Automatic Transmission Fluid. Using aftermarket "universal" ATFs or fluids designed for other manufacturers can lead to shifting problems, premature transmission wear, and costly damage. Honda transmissions are particularly sensitive to the correct fluid properties.

Differential Fluid

The 2021 Honda Odyssey is a front-wheel-drive (FWD) vehicle and therefore does not have a separate rear differential or a transfer case. The transaxle assembly (transmission and differential combined) uses the Honda DW-1 Automatic Transmission Fluid discussed above to lubricate the differential components integrated within the transmission case.

Maintenance Interval: No separate service interval for differential fluid as it shares fluid with the automatic transmission.

Pitfalls: N/A

Brake Fluid

The 2021 Honda Odyssey requires Honda Heavy Duty Brake Fluid DOT 3. The system capacity is "as needed" during servicing, as it's a closed system unless a component is replaced or a flush is performed.

Maintenance Interval: Honda recommends inspecting the brake fluid level and condition at every service interval. A full brake fluid flush is typically recommended every 3 years, regardless of mileage. Brake fluid is hygroscopic, meaning it absorbs moisture from the air, which reduces its boiling point and can lead to corrosion in the brake system.

Pitfalls: Never use DOT 4 or DOT 5.1 brake fluid unless specifically indicated. While DOT 3, 4, and 5.1 are glycol-ether-based and generally compatible, DOT 5 is silicone-based and incompatible with DOT 3/4/5.1 systems. Mixing incompatible fluids can cause severe damage to the brake system seals and components. Always use fresh fluid from a sealed container. Brake fluid absorbs moisture rapidly once exposed to air.

Power Steering Fluid

The 2021 Honda Odyssey utilizes an electric power steering (EPS) system. Therefore, there is no power steering fluid reservoir or associated fluid to check or replace. The system is electronically controlled.

Maintenance Interval: N/A

Pitfalls: N/A

Washer Fluid

The 2021 Honda Odyssey uses Honda Windshield Washer Fluid. The washer fluid reservoir capacity is approximately 0.9 US gallon (3.4 liters).

Maintenance Interval: Check and top off as needed. It\