I was using Tempest massive electrode spark plugs with my Franklin engine. I now use these ones on a O-360 engine. I removed the other brand of spark plugs and because of the angle and distance with baffles, it was very difficult to insert the socket and wrench on the rear spark plugs. While the overall dimension of the Tempest ones is the same, the areas where the socket fits is lower on the Tempests. Unsure if this is good or bad (the shorter socket I use graphs only half of that nut area), but it is for sure easier to put the socket in that tight area.

Never had an issue with Tempest plugs. I just replaced the existing Champoions and yes, of course youd expect a difference with new plugs, but the plane runs superbly now, and I dont believe you get any better product vs. Champion. The up-charge you pay is for their pedigree, vanity and heritage, but even Mike Busch will say in his books engines and Manifesto how hes never had nothing but a great experience with Tempest plugs....PS, same for the oil filters.

I love these plugs. I have an above mid TSMOH engine and was burning closer to 4 gal. an hour and getting pretty dirty plugs. I checked the resistance on my old Champions and the majority were either through the roof or about there, but certainly no 2 even close. When I purchased the Tempest Plugs I saved the box and labeled each with the starting resistance when still new. They are all very close. I track the map the placement of each plug and am very impressed by the stability of the resistance measurements. I will always buy Tempest plugs from now on. My Champions had only 126 hours on them.

A brand spanking new set of spark plugs solved all my problems. Ok, not all my problems... I still have the ex-wife and I am still expected to show up for work on a regular basis. But the stumble that I had when I advanced the throttle is gone and the engine runs smoother than it had in a long while. So, with those two things, my other problems are forgotten for a while. At least until I tuck her back in the hangar and close the hangar door and have to come back to reality.

We love our Tempest Plugs. Made in America too.

I have always had excellent service and quality products.

Good product. Arrived earlier than expected

Got 700 hr on these in my C172 O320 D2J before the center went football. Pretty good in my book.

Fast shipping from Spruce!

I had an intermittent stumble I was trying to sort out and replaced Champions that were only a few hundred hours old (previous owner) with these Tempests and problem solved. The resistance in those other plugs were different in every plug! These were all exactly the same. Happy.

Great plugs that always test good on resistance. More prone to rusting barrels than champion due to being polished rather than gslvinized. But work great.