1989 Mercedes Benz 300e Spark plugs

MERV7

MEMBER
1989 MERCEDES BENZ 300E
6 CYL
2WD
AUTOMATIC
25,000 MILES

I need to replace the spark plugs BCP5ES/Y
The shops keep offering me BCP5RES and claim the Y's only come in R now.
They tell me they are the same.
How can they be the same if they have a different number.
I know the electronic ignition module on this model costs thousands if it fails. I have no desire to put in plugs that might upset it. They tell me the R is only to suppress ignition noise in later model electronic equipment like the radio. Do you have any real knowledge about this?
Thanks
Merv

1 Reply

GFIMOTORCARS

MECHANIC
673 POSTS

There are constantly updates made to automotive parts to increase efficiency and operation. This is one of those cases. The spark plugs were more than likely updated for this reason. A concern for many spark plug manufacturers is electrical interference with vehicle components. They are telling you that the R is for noise supression of the circuit. This is more than likely the case as many times spark plugs can cause electrical interference with other components, like the radio. The number to be concerned with is the BCP5. The rest of the number is describing updates and changes to the BCP5 model of plug.