Hi olpos and all -

The last 3.0 engine I tore down (late '87 model) had a dropped valve that actually stuck into the piston, like a sword in stone. The carbon build-up was incredible, and the previous owner used regular fuel.

Pinging or not, carbon build-up is not good for piston rings, cylinder walls, nor the valve train (not to mention the catalytic converter).

My W124 book shows that some 2.8's and 3.0's have 10.0 compression ratio, as well as 9.2, and the 2.6 as having 9.2.

I have the 2.6, and you can bet that premium fuel will always enter my fuel tank. 91 to 92 octane is the average in my area, but 93 can be located.

I believe limeyb spoke the truth.

__________________
'87 300E | 2.6 engine
Artic White - Navy blue interior, chrome rims, very clean and sharp!
91 300E
89 300E


The rest of my collection are just cars and trucks...no more "automobiles"...