Volvo multi-ground spark plugs - why?

[L.E.V]

Up until now, I have only used single electrode plugs in my 98 S70 N.A..I've used the 2 plugs specified in the manual for the majority of miles on the car which is currently 242k...I've had no issues at all using Champion 344 aka RC9YC, along Bosch 7555 copper core plugs which are made in Germany..back in January i bought Bosch fr7dpp fine wire platinum on clearance from Rock Auto...both throttle response and acceleration is a bit better with platinum plug as opposed to copper but not by leaps and bounds...also my highway mileage is up a slight bit as well...i pour Pennzoil 10w40 yellow bottle along with a Mann oil filter...no issues at all with the new Bosch platinum single electrode plugs nor with the old school copper core plugs...

 

[rekit]

My 2001 Tacoma v6 5Vz has a reminder on the underside of the hood to use double electrode plugs always, and they come from the factory with ngks on one side and densos (if I remember right) on the other, probably because the coils are on the passenger side and has another (long) lead going to the drivers side. But you won't see that in the replacement charts I've seen. Same plug all around. All I know is they work either way, I could not tell any difference.

 

[ElectroMechanoMan]

Aircraft use a similar design spark plug and have for years. In that case I believe it was another level of redundancy along with 2 separate ignition systems. I can’t really understand any advantage in a car. Single electrode plugs have worked just fine in almost all applications.

 

[KevinMalone]

A puzzler that seems to contradict Volvo's approach:

BMW specs a multi-ground Bosch ZGR6STE2 plug with nickel core and nickel grounds (30k mile life) for the high performing N54:

https://www.boschsparkplugs.net/bosch-zgr6ste2-0242140507-super-spark-plug

Meanwhile the plebeian N52 gets fancy fine tip double platinum spark plugs, such as the Bosch FR7NPP332:

My takeaway is to just go with what's specified, since the engineer responsible is probably smarter than you!

 

[nthach]

So Toyota uses a similar plug on the earlier Lexus D4-S V6/V8s(2GR-FSE/4GR-FSE/1UR-FSE/1UR-FXE/2UR-GSE) and the 3.5L 2GR-FKS/FXS V6 used before the Camry/Sienna became a hybrid and the Highlander/RX/Tacoma got downsized to a turbo 4. It’s a special Denso FK20HBR-8 or NGK equivalent. It’s a tri-ground plug designed to handle carbon buildup. 60K replacement. Toyota went back to a single ground strap plug on the M20A-FKS/FXS 2.0L and A25A-FKS/FXS 2.5L I4s with 100K replacement.

 

[KevinMalone]

So Toyota uses a similar plug on the earlier Lexus D4-S V6/V8s(2GR-FSE/4GR-FSE/1UR-FSE/1UR-FXE/2UR-GSE) and the 3.5L 2GR-FKS/FXS V6 used before the Camry/Sienna became a hybrid and the Highlander/RX/Tacoma got downsized to a turbo 4. It’s a special Denso FK20HBR-8 or NGK equivalent. It’s a tri-ground plug designed to handle carbon buildup. 60K replacement. Toyota went back to a single ground strap plug on the M20A-FKS/FXS 2.0L and A25A-FKS/FXS 2.5L I4s with 100K replacement.

Fascinating. Found this in the Denso spark plug manual:

This could explain BMW's choice of spark plug for the N54 since it has direct injection

 

[ammolab]

One of the outboard manufactures used them and Kawasaki used a similar plug in the 1971 Mach III I had back in the day.

I had a 1970 Mach III and it used those

surface gap plugs