Question about spark plugs

Is there a difference in a spark plug for a 90 and a spark plug for a 99?

I have a set of OEM Champion plugs I bought for my 90 and never used them, and now I want to give my 99 a tune up and figured I can use the one's I bought and save a few bucks. On the auto zone website they have a different part number but the specs are the same.

Any idea?

Thanks
-Mike

If you go to the Champion website, you can really get into the details of the spark plug. Heat range and all other details. Facts would be better than opinions. Opionios might come in when you decide whether a small heat range difference matters or not.

The facts we need to know to give informed opinions: Exactly what Champion plug do you have that you are considering using????

Assumption???????? 4.0?

they'll probably exchange them at your local import zone. Make sure they're the right PN, those guys make a lot of mistakes (personal experience with an oil filter... you can imagine that was fun with no back up vehicle)

Skreed said:

Is there a difference in a spark plug for a 90 and a spark plug for a 99?

I have a set of OEM Champion plugs I bought for my 90 and never used them, and now I want to give my 99 a tune up and figured I can use the one's I bought and save a few bucks. On the auto zone website they have a different part number but the specs are the same.

Any idea?

Thanks
-Mike

Click to expand...

There is a HUGE difference in the reach of the plug (also assuming 4.0) so I would not use them.

1990 RC9YC 14mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor','2','1')">Resistor, Copper Core, Projected Tip, Heat Range 9

1999 RC12ECC 14mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor','2','1')">Resistor, .290" Projected Core Nose, Copper Core, Heat Range 12

From the specs, it seems like you could use them. The heat range being 3 steps colder would concern me that the plugs could foul out pretty quickly.

Sorry 88 Wagonman, please enlighten me if I am ill-informed about the reach? Were you referring to the amount of porcelain that projects into the combustion chamber? I do believe that affects the heat range.

winterbeater said:

1990 RC9YC 14mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor','2','1')">Resistor, Copper Core, Projected Tip, Heat Range 9

1999 RC12ECC 14mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor','2','1')">Resistor, .290" Projected Core Nose, Copper Core, Heat Range 12

From the specs, it seems like you could use them. The heat range being 3 steps colder would concern me that the plugs could foul out pretty quickly.

Sorry 88 Wagonman, please enlighten me if I am ill-informed about the reach? Were you referring to the amount of porcelain that projects into the combustion chamber? I do believe that affects the heat range.

Click to expand...

87-90: RC9yc ------------91-98 RC12lyc--------- RC12EEC 99+
I guess it depends on your terminology, but if you look at the difference in heat range, they are not the same. Running the shorter\hotter plug can cause engine damage

I wouldn't run them.

Besides, 99+ Chryco changed the recommendation to NGKs for driveability issues.

Thanks for the info....not really a big deal, but I was trying to save a few bucks. If there's any question about it I'll just buy new ones, or maybe they will exchange them, don't have the receipt but I could always try.

If they are new, you should be able to exchange them at your local parts store..
Usually places will EXCHANGE stuff or give credit if you do not have a receipt.