Genuine Aisin ATF-0WS, the World Standard fluid that Toyota, Lexus and Scion units are actually built to run. Aisin is the OE supplier for these transmissions, so this is the same low-viscosity spec as Toyota WS at a shop-friendly price. One quart, right for a drain-and-fill top up.
If you are servicing a late-model Toyota, Lexus or Scion automatic, the fluid spec is not a suggestion. These transmissions are calibrated around Toyota WS, and Aisin is the company that builds the units in the first place, so their ATF-0WS is the same World Standard fluid coming straight from the original equipment source. Put a generic multi-vehicle ATF in one of these and you will feel it in harsh or hunting shifts, and you can shorten the life of the valve body.
This is a genuine low-viscosity WS formula. The thin, stable viscosity is what lets these boxes shift smoothly cold and still hold up at temperature, and it is a big part of the fuel economy these vehicles are rated for. It resists shift shock, keeps the friction coefficient where the calibration expects it, and flows cleanly in cold weather so first engagement is smooth.
One quart is the right unit for a drain-and-fill or to top off after a service. On a full fluid exchange you will want several. Always set the fill level using the transmission temperature procedure for your vehicle, since these units check level by temperature rather than a traditional dipstick.
| Type | Genuine Aisin ATF-0WS, meets Toyota WS (World Standard) |
| Fits | Toyota, Lexus and Scion automatics that specify Toyota WS fluid |
| Volume | 1 quart |
| Viscosity | Low-viscosity, fuel-economy formula |
| Source | Aisin, the original equipment transmission manufacturer for these units |
| Best for | Drain-and-fill service and top-ups; buy multiple quarts for a full exchange |
