In the big scheme of things, no gimmick spark plug is going to make a difference in the performance of an OEM 1.5L Prius engine, compared to a new OEM spark plug. Not gonna happen. Now, if you install the gimmick plug to replace a 120k mile OEM plug, you may see some minute difference, but you would see the same difference if you installed new OEM plugs or even new $1 autolite plugs (the autolites would just need to be replaced sooner) As long as the ignition system is healthy and the spark plug makes the spark, there isn't going to be any difference in performance. Maybe a three prong plug will increase compression some infinitesimally small amount due to the extra prongs making the combustion chamber volume smaller. Now, if we're talking about a forced induction, high performance engine that can be prone to misfire due to high cylinder pressures, then anything that increases the chance of that spark occurring properly will be an advantage. The 1.5L Prius engine does not fall into this category.
FYI: Toyota specs a dual electrode plug for the 5VZ-FE 3.4 litre V6 used in their trucks from the late 90s to early 00s. I had that engine in my '02 4Runner, and to describe the performance as ponderous is being charitable. Many owners would come on the forum seeking help with misfiring, high RPM performance, and MPG loss. The first question we'd ask was, "Are you running single electrode plugs?" Second questions was, "Have you cleaned your MAF sensor?" I don't claim to know why that particular engine required dual electrode plugs, but it did/does. It's not a high performance engine. Just sayin'.
I have a neighbor who got an 02 Taco for pennies on the dollar due to the wrong plugs being used . The prior owner had a major servicing done and when they got it back it was all sorts of bad . It had 230k miles on it at the time and they were going to trade it in. My neighbor got it for trade in value . Tried swapping the plugs and that did the trick. Got 340k on it now and still matriculates down the road.
It's an interesting question. I wonder if it had anything to do with the one coil/two cylinder style ignition system it had. I think a lot of engines have used that, but many use the iridium plugs now. Our old 2003 Santa Fe has 3 coils/6 cylinders but uses iridium plugs. 90% of the plugs offered for those style engines are now fine wire iridium.
I didn't say that at all. That specific plug may compliment the design of the combustion chamber. It may also allow for some wear of one electrode while maintaining the ideal gap on the other one, allowing for longer plug life. Thinking that you can gain anything useful by replacing OEM plugs rated for 100K miles with a multi-electrode design is just being gullible. When both plugs are new, there is NOTHING inherently better about having multiple ground electrodes.
