This is not exactly news, but news to me and the real deal based on my literature review. DENSO to Release Fuel-saving Spark Plug / News Releases| DENSO CORPORATION The "Twin Tips" (TT) are widely available now at the low price of $3 per piece. The only problem is they are not "long life" plugs. I suspect they will last up to 30,000 miles. Anyone tried them?
Both the Civic and Insight (G2) hybrids have dual plugs. This sounds like the same concept, but merged into one plug? Whenever they say "2% more efficiency" they are comparing to a standard car with no improvements. If placed into an already-efficient car like the Prius, it might only be 0.01% measurable improvement.
Interesting, I looked it up and looks like they have 2 spark plugs per cylinder. Not sure why. Now, the Denso TT plug is about having 2 tipped electrodes as opposed to the regular modern plugs that have one tipped electrode (center) and a ground strap that is not tipped (due to durability issues). The bigger the ground electrode is, the bigger inhibition in flame propagation (kernel quenching). This is why the double tipped spark plug is the holy grail of spark combustion.
The 4cylinder engine for the old Ford Ranger had dual spark plugs. It seems there have been many engines so equipped through the years. It appears Alfa Romeo was the first to do so, with others following. Igniting the fuel charge at two different points allows for a more complete burn. Which can improve power, efficiency, and emissions. As to this spark plug, I can see how the geometry of the electrodes can allow a greater exposure of the fuel charge to the spark. Part of that is due to the narrower electrodes. The electrodes on a long-life, iridium plug are already quite narrow. So I don't think any improvements compared to one of those would be as good.
Speaking of spark plugs are 2010 Prius had the plugs replaced at about 108,ooo miles or so. The plugs looked like they could go another 100,000 miles with no problem. I would not have replaced them until 200,000 miles if I knew they would look like that. .
They ignite in a staggered pattern, controlled by the computer, for a more efficient explosion. Just changed the plugs on our previous '06 Civic Hybrid, at 160000~ km, it's now with our son.
Your right, 2 spark plugs in one cylinder is nothing new. They had it back in the 60's-70's on some 2 stroke dirt bikes (off road motorcycles). The 2 strokes were famous for "fouling the spark plug" so I think Bull Taco came out with the first two spark plug race bike. A friends Dad had one. From my memory it was a 250 Bull Taco Pursang, both plugs were not in use at once, but he would simply pull the plug wire off the fouled one, snap it down on the 2nd plug, kick it back to life, and away he went. I was but a kid back then, with my Hodaka Ace 100. Good ole days!
Did they look like this? These are the OEM Denso Super Ignition Plugs from my RAV4. Long life "needle to needle" Iridium Spark Plug. This is the plug that the TT is a cheaper copy. Unfortunately the original SIP design is not available for prius yet.
Your post got me interested, I invested some time in google search and apparently the AC Delco Professional iridium doesn't have platinum wire ground electrode like you said. It just has a small platinum disc/plate (not wire), just like other double platinum or long life iridium plugs. Furthermore, it's made for AC Delko by NGK, so it's a re-branded laser iridium plug. Maybe you are talking about OEM plug? Possibly a re-brended Denso plug?
No, I didn't say they have a platinum ground wire. There's no pic in your post #11, so I looked up the Denso Super Ignition plugs. They didn't look like the drawing, so that's why I said the Delcos were close to your drawing in post #3. In other words, not just a plain ground, but a disc of platinum across from an iridium center electrode. I couldn't get the platinums any more, so I stuck the iridiums in the Buick.
Sorry the picture of my Denso SIP didn't show up. Here it is again: The drawing in the post #3 was from Denso TT, a cheaper version of SIP. The fine wire is less fine, 1.1 mm vs 0.55/0.7 mm for SIP. Here is how Denso TT looks: What's confusing, Denso TT in USA is platinum/titanium while overseas is nickel/nickel. Either way, none of those "needle to needle" advanced plugs are available for the gen 3 Prius.