The service maintenance is "calling" for spark plugs change on W166 63AMGs every 5 years or 50K miles. My ML63 is almost 7.5 years old, but still has only 30K miles. I have no issues (knock on wood), but what do members with 63s and low mileage do/did regarding spark plugs change?
(As a side note, my dealer "insisted" on transmission oil/filter change when car was 4.5 years old but had only 12K miles (service manual is "calling" for transmission service on 63AMGs every 3 years or 30K miles. However, they did not "insist" on spark plugs replacement when last served with them when car was 6 years old and had 24K miles).

 

Do the services now. That’s what I would do.

 

I would do my mileage and not time. Spark plugs are not like tires or oil that are affected by time.

 

Just received quote from my friendly MB dealer. $695 LABOR ONLY. Parts are extra, which I already have, otherwise additional $270. Total install with their parts over $1K with tax. My non authorized large German cars only service dealer - $375 labor. Insane difference.

 

That's pretty standard. A good indy will be 1/2 or less of stealer ship. 1/2 labor rate and they will use OE equivalent parts that are not necessarily in a Mercedes box so half or less on the same parts.

I just changed plugs and coils on my ML63, not bad at all. About 2 hours or so working methodically. You just need the special 12pt wobble socket and a short extension, and a torque wrench. About $100 for plugs and the socket.