There's nothing inherently wrong with Vaseline (I use it for all of my laser resurfacing patients before their skin is healed to help keep normal tissues fluids from drying out and forming a scab) on your scar, but your scar is dry because it has no normal sweat or lubrication glands, and must be moisturized from adjacent skin or from what you put on it. Vaseline is petroleum jelly, and will not evaporate or be absorbed, so it sure seems to work. But it's greasy and messy and stays on the surface. Consider a slightly thinner oil such as Vitamin E oil (available in a jar or in Vitamin E capsules), and gently massage the scar with the oil. This helps the scar soften, the lymphatics to grow in the healing tissue, and any local swelling to diminish, while absorbing into the tissue and moisurizing the scar.
Any commercial skin lotion is also a suitable alternative or additive, but must be applied frequently until the scar heals, matures, and becomes lubricated from its neighboring skin. Consider Eucerin, Vaseline Intensive Care, Nutradern, Lubriderm, etc. Whatever is cheapest and does not irritate your skin or your nose (many lotions have scent added) is the best.
Also, remember to keep the scar out of the sun, as ultraviolet can permanently darken a maturing scar. A Chap stick or lip balm with sunscreen added (highest SPF the best) is another easy-to-use moisturizer, but also one of the greasier ones (see Vaseline above!).