Evansaero

I've been putting this off only because I hadn't felt a need other than the mileage on my car.

I have 113,800K miles and in the last 2562 miles I averaged 18.8 with combined city/hwy driving

Spent 2 hours and it should have been more like 1 hour...

Pulled one side at a time. It took a lot of torque to get them out and my first thought was these plugs must be original.

The passenger side had several oily threads on some of the plugs, pretty consistent on the deposits with a reddish-brown color.
Installed NGK IFR6D10 and didn't replace any wires or coils. Nothing feels different after the change so as far as I feel its a job well done

The next task to tackle will be the value covers. Maybe lol

tensleep80

Wow, those were stuck in there pretty good it looks like.

Stephen04E55

definitely appear original...the MB logo on the plug is indicative of an OE plug. I am doing mine soon on my C55 and they are likely OE as well.

Evansaero

Congrats Stephen on picking up a C55! Very Nice Find!

and just to follow up on my plug change MPG hasn't changed a bit but that's kinda what I was expecting

Stephen04E55

thanks..I didn't have time to switch all of the plugs but I did cylinder 1 and the 91K plugs were original NGK with the MB logo.