Spark plugs - Toyota Nation Forum : Toyota Car and Truck Forums

tneumeister · 08-17-2010, 04:37 PM

My 2000 Corolla has a sticker under the hood that says to use only "Twin-grounded spark plugs". The owners manual says to use only iridium-tipped plugs. The two part numbers listed in the manual are for single-ground iridium-tipped plugs. Nobody makes a "twin-grounded, iridium-tipped spark plug". Should I use a twin-grounded platinum or a single-grounded iridium-tipped plug?

teppista881 · 08-17-2010, 05:52 PM

Definitely go with the iridium plugs listed in the manual, and only those.

ilovecorollale · 08-17-2010, 07:16 PM

You will run great on single tips but i do really wonder and would like to buy those double tips and see if there's any difference in them.

BigTDogg (MA) · 08-18-2010, 12:27 PM

Quote:

Originally Posted by ilovecorollale

You will run great on single tips but i do really wonder and would like to buy those double tips and see if there's any difference in them.

Go for it, they'll run like crap, and you'll reinstall your iridiums. Double tips are gimmicks, nothing more, nothing less.

ilovecorollale · 08-18-2010, 01:09 PM

Quote:

Originally Posted by BigTDogg (MA)

Go for it, they'll run like crap, and you'll reinstall your iridiums. Double tips are gimmicks, nothing more, nothing less.

So i suppose you have tried it before then???

BigTDogg (MA) · 08-18-2010, 02:00 PM

Quote:

Originally Posted by ilovecorollale

So i suppose you have tried it before then???

Bingo, Bosch plugs to be specific. Lesson learned, NGK Iridium only.

**TOYOPARTSMAN** · 08-18-2010, 02:10 PM

Go with factory plugs. They are designed for that engine, the iridiums last 120K. I will also tell you that I have seen more engine runs rough, missing, lack of power, etc issues solved by just putting back in factory plugs after someone put in Bosch, or other brand.

CorollaRollin98 · 08-18-2010, 04:30 PM

dont ever buy bosch plugs, they suck horribly for out engines, NGK or Denso

teppista881 · 08-18-2010, 07:42 PM

Glad to see the regulars on the forum agree about at least one thing!

tneumeister · 08-21-2010, 10:29 AM

Thanks guys. Put in NGK single-ground iridiums and it's running fine. Still can't find a human being that can tell me why the recommended plugs are single-ground and the sticker under the hood warns to use only double-grounded plugs.

all2baka · 08-21-2010, 12:03 PM

If you're using Denso or NGK platinums, they'll be double-grounded while iridiums will be single.