Valvoline
20w50
sae 5w30
5w20...use synthetic
Synthetic 5W-30 motor oil. Use pennsoil, castrol, or GTX. Also depends what year it is. From 80's-2000, 10-30. From 2001-present, 5-30.
Use an oil viscosity of 5W-30 or 10W-30--your preference.
you should use 5W20 for winter. It's best for cranking in winter.
The exact weight oil recommended by Hyundai. The brand is your choice, as all major brands are good. I personally use Pennzoil.
Open the owners manual that came with this brand new car and read it. It will tell you exactly what weight oil and how much to use.
Castrol Edge with Titanium which I believe is one of the best oils available.
I use 10w-40 in mine, but I can't find a definite answer. In other words, it hasn't blown up yet!
The answer is use 10W-30 for engine oil in the 2003 Hyundai Tiburon GT.
Hyundai recommends SAE 10w40. On a car this old I recommend you use a High Mileage oil.