sparkplug heat range WR7DC/W5D
 

Bought new Bosch plugs WR7DC because Bently listed that number. I now have the plugs out, the old ones are W5D and look good (tan)but worn. now looking up inside engine cover I spot sticker which says W5D. then to make matter worse B. Anderson says 225T30W5D. I now can visually see porcelin goes deeper into shell on the wr7dc..anybody have a heat range chart so I can see what I am dealing with here, the auto parts store has no idea.

Take them back! The 'W' means 14 mm, 'R' means built-in resistor -- irrelevant! The '7' or '5' is the heat range, and most important number! The 'C' at the end means copper core, basically irrelevant, too.

The store should have some W5DC or WR5DC plugs that are current replacements for the ones that camwe out ... if not, find another store that does!

------------------
Warren Hall
1973 911S Targa
1992 Dodge Dakota 5.2 4X4 parts hauler

The WR7DC is not the correct plug for your 82SC. That listing is an error in Bentley, and pertains to the 3.2 Carreras. A "7" is 2 heat ranges hotter than the W5DC you should be running.

------------------
'81 SC Coupe (aka: "Blue Bomber")
Canada West Region PCA
The Blue Bomber's Website