2003 Chevrolet Malibu: What is the oil type and capacity?

EacH2003 Chevrolet Malibu will be fitted with the same 3.1 liter V6 engine, so regardless of Your trim level, You'll be using the same type and amount of motor oil -- specifically, 4.5 quarts of SAE 5W-30 full synthetic. In warmer climates, it's possible to use SAE 10W-30 or SAE 5W-40 full synthetic motor oil, but this isn't recommended if You can avoid it. The reason for the recommendation against is because oils with higher weights equate to a thicker oil, which introduces friction into Your engine's operation. This can and will cause premature wear and tear over time, which can and likely will cause early engine failure. Therefore, stick with the manufacturer's recommended oil with the lowest weight, even if it costs a few more dollars per change; You'll save out in the long term.