The USGA tests all new driver heads to ensure that the COR does not exceed acceptable standards. This means that the amount of spring in the clubface is no more than what is allowed. What this also means is that manufacturers of golf clubs that advertise exceptional increases in distances with their clubs are either not telling the truth or they are misrepresenting the benefits of getting the proper shaft with proper loft. They're telling you that all you need to do is buy their club and get 30 yards more off the tee. That's a lie. I can't emphasize enough the benefit of going to a quality club fitter and have them "fit" you with the proper shaft (the engine of the swing) to match the driver head loft and lie that is best for you. Don't just buy into the nonsense that a club can give you more distance. It takes a proper fitting.