It's almost time for a new set of spark plugs. Anyone change theirs yet? With what? I suppose I'll go with what the manual says (don't have it with me). Any thoughts that indexing may help MPG? I indexed my plugs on my V12, and it actually was noticable.
Just wondering how easy/hard it was on the HCH I. Wires too?

Thanks for any input.

I've heard the plugs are numbered according to how the hole in the head was threaded...to allow the gap to face a certain direction.
If this is true remember you can't put the plug from Cyl 2 into Cyl 4 etc. (Unless those two cylinders had the same number stamped onto them)

Efficient drivers do it better.
1003 miles a tank personal record. 74MPG calculated. HCH1 CVT

Which car do you own that has a V12? (waits with curiousity)

VRRRRROOOOOOMMM!!!! hehe, how do you keep tires on it? ok, I am done, Kudos to you though!

'94 Jaguar XJ12, 6.0 L V12. Gets considerably less MPG than the HCH ; )
I checked prices on the OEM spark plugs (NKG IFR5G-11K, and Denso SK16PR-L11).
They are VERY pricey! I wasn't expecting to pay ~$13 per plug!!! Wow.

I replaced my plugs not long ago. 2003 HCH that I got used. Didn’t do anything special, just replaced them. Got AC Delco equivalent to the recommended plugs from NAPA. They were a little pricy (about $8 each) but not $13! They looked the same (tapered center electrode, etc.) Didn’t loose any performance . . . may even have gained some FE, but I don’t know how old the other plugs were (I assume they were pretty old, car had close to 100,000 at the time) and how much that affected things.

kernk

No one mentioned there's EIGHT spark plugs on this engine (dual-plug heads).
Anyone know how to remove the 'snorkel' thingie that covers the front 4 plugs?

The "snorkel thingies" (and I believe that is the proper technical term) cover the back four plugs as well . . . the non-technical term for “snorkel thingie” is ignition coil (I think – or something like that, I am guessing). Anyway, just undo the nut on the snorkel thingie, detach the wires that are clipped on to it and pull it off.

You will need a very long extension for your socket wrench (I put two extensions together to make a long enough one), because the plugs are WAY down in there! If you don’t have a rubber gripper in your plug socket you will never get the things out . . .

Not the coil 'thingies', but the air intake thingie.

Anyone have any pics so that I can see what you are talking about?

The plastic cover that says IMA (as I think you know) just pulls off. The forward plastic cover had two bolts (which were under the first plastic cover) and then you just pull real hard and it comes off too. it is held down by two "pins" that fit through rubber rings at the bottom - pulling pretty much straight up works fine. I just removed the hose/tube from the air cleaner where it attached to the front cover (again just pull it out) . . . I didn't remove it from the air cleaner housing. That was all I removed to get to the plugs.

I hope I am being of some help . . .