I would go with Tempest in a heartbeat. Here is the reason...The next time you clean your Champion plugs, do as the Champion Service manual requires and measure the resistance of the center conductor. You will be surprised how many of your plugs will be high resistance but still seem to work fine. I have found that some plugs will measure more than 100k ohms when a new Tempest is very steady at 1 k ohm, even after 500 hours. I think Champion has been sitting on their laurals for far too long without competition. I will never buy another Champion plug until they reengineer it. For what its worth..
