My Mazda has 55k miles on it and is running very well. However I started to experience dry starts. This only happened when the car would sit overnight or for a long period of time. When I started the engine I would hear a knocking noise for 1-2 seconds and then it sounded fine. Well this had be worried considering that my car just came out of warranty, 50k miles. After researching I decided to make the switch to Castrol Syntec 5W30 full synthetic in combination with Lucas Synthetic Oil Stabilizer. My thought was the Lucas Oil Stabilizer would bond to the valves, lifters and camshaft and would eliminate the dry start. Well it did just that!! No more dry starts at all. Starts much smoother and no noise. Lucas has a great reputation and my experience backs it up!!