There is no substitute for product or service knowledge. Any source of information should be considered. A benefit is what the product or service does, and what the buyer gains from the feature. A benefit is the specific outcome of the feature. A feature is something the product or service already has.
Benefits are what motivate people to buy.
If those tires are HP 90's, and are proven to reduce accidents by hugging wet roads, then we have the benefit of those tires. Stress that the reader is less likely to have an accident, if he buys the tires. The experts say that the emotion most often used to manipulate people to buy is fear, and the thousand variations of it. Walk a mile in the buyers' shoes. The image, if used, is near the headline.