twowheelin

Recently did a change out of my plugs at 50K miles. Here's what they looked like:



OEM NGK Plugs @ 50K Miles.

Original vs new plug

Enjoy!

ezshift5

Was the MPG improved following plug change?

On a prior V-6: got over 100,000 (NGK) and IIRC fuel economy was NOT an issue.



ez

twowheelin

No difference in MPG. Startup was a little more immediate and idle seemed a bit smoother (if that's possible...) after plug change.

Magnus Rostadmo

I have a friend who is running a local car parts store here in Norway. He is a Mercedes-freak and happens to know some guys at the Mercedes factory. In fact one of them was responsible of construction of the ignition system on the w204 - M271 EVO-engine.
So - when i ordered Iridium-plugs for my C200 (M271 Evo) he checked with the guy in Germany and was told that it should not run on Iridium type sparkplugs - i do not know the whole story behind why not, but something with the resistance requirement, low or high - do not know. So why several plug manufacturers prescribe Iridiums can be questioned. Surely it will run on them, but none of them are intended and well suited - as said by the MB-engineer.

He sent me the same plugs, NGK R, (without the blue MB-Star) -- similar to yours original i believe.

My old ones had run 113`km. They looked as yours with about 2 mm opening. The engine behaviour after swap where similat to what you described.