Hello everyone. I've got a fresh batch of German Castrol Syntec in my trunk but I'm having second thoughts of putting it in suddenly. With the fact that I'll be going to the track several times and also on the dyno to PCM tune in the next month or so, and I drive my 1998 GTP fairly brisk on a regular basis, should I be putting in something a little thicker to protect it during the warm weather? Its been on my mind to go get some Mobil 1 15w50, even though the engine is rated for 10w30 oil. Any advice for the best engine protection?