Grilling Tip #5. Grease the Grill
No one likes their meat sticking to the grates when grilling. Too many times when grilling chicken I've left skin on the grill. One way to help prevent this is by greasing the grill before starting.
Some say you should only use a wadded paper towel dipped in some oil and applied to the grates with tongs but I still like using a spray oil. Either way, if your grill is clean, hot and greased before you start cooking, you have a much better chance of not having any sticking problems.
If you are cooking something that has been marinated in oil or using an oil based rub, you really don't have to grease up the grill. It's a bit redundant. What type of oil you ask?
As I said earlier, I typically use Pam or some generic version of it but if I were using oil on a paper towel, I'd most likely use Canola, Grape Seed or Safflower Oil. There's no reason to use an expensive olive oil to lubricate a grill. As soon as it hits the hot grates, it looses its expensive taste.