We have a 2002 GTP with 109,000 miles. We bought the car a few months ago and I'm guessing the oil is conventional. The engine runs great but I'm thinking about running a synthetic blend motor oil. I've heard full synthetic is awesome motor protection, helps the motor run cooler, offers better protection at cold start up etc. However I have also heard that it should start to be used at a certain mileage and can lead to oil leaks. Common sense tells me a blend may be the way to go to get the best of both worlds. We plan on keeping the car for a while and want to keep the engine well maintained and running well. The only mod we have put on the car now is Intense K&N cold air intake (fender well) Planning on headers, smaller pulley and PCM next year. Thoughts and your experience would be greatly appreciated.