[svx_commuter]

I think it may be wise to slow down and not drive so hard. The coolant level should not be changing that much. After a couple of warm up and cool down cycles the engine should be solid with coolant and no air. No matter how hot it gets the coolant should not be overflowing out of the expansion tank with solid water in the system. A head gasket leak will overflow the expansion tank. I have added Suabru coolant conditioner to my coolant in the hopes of helping with that problem.