How to Choose the Oil and Fluids for a Hyundai Sonata
- 1). Run SAE 10W30, 10W40 or 10W50 engine oil in normal temperatures. Cold climates may require 5W30 or 5W40, while hot climates need 20W40 or 20W50.
- 2). Maintain your transmission at regular intervals with Hyundai Genuine Parts automatic transmission fluid, Diamond ATF SP-III or SK ATF SP-III for automatic transmissions. In a manual transmission, use Hyundai Genuine Parts manual transmission fluid, 75W90 API GL-4 viscosity.
- 3). Mix one part clean, distilled water with one part ethylene glycol antifreeze. Using antifreeze with a non-ethylene glycol base may lead to premature corrosion.
- 4). Top off your power steering fluid reservoir with PSF-3 type fluid.
- 5). Refill both brake fluid and hydraulic clutch fluid with DOT or DOT 4 brake fluid, or equivalent. For your own safety, don't use non-recommended brake fluids, and remember that vehicle fluids such as transmission fluid, brake fluid and antifreeze are generally not interchangeable.
Source...