Leaded Petrol

[chillbrazill]

Have been looking a 230SL and asked about hardened valves, I was advised that 'a power plus valve' was fitted which 'feeds replacement tin rather than lead'.
Can anyone shed any light on what this is and what I should be looking out for or checking for on this or future cars.
Regards
Mike

[J. Huber]

If I follow -- I think it might be baloney. Back when we switched from leaded to unleaded in CA, rumor had it our cars would suffer. Mine hasn't... These cars run fine on unleaded.

James
63 230SL

[ja17]

Hello,

All Mercedes cars since the mid 50s used hardened valve seats and superior steel alloys for the valves. These cars do fine on high test unleaded fuels.

Joe Alexander
Blacklick, Ohio

[jameshoward]

In the interests of discussion...

My German mechanic who has worked on these engines for a long time believes that we should add a fuel supplement to each tank of unleaded - it's for cars that were built to run on leaded and one adds about 10ml per 10 litres of petrol. It's not that he feels they won't run on unleaded, but more that he feels the zinc in the additive (I think that's what it is) just helps keep the valves in good shape.

It's quite cheap so I do it anyway. He has a tendency to moan and lecture if I don't listen so it's probably easier than not doing so.

JH

[Rolf]

The "lead" in leaded gasoline was just that, lead. It was used to boost the octane rating.  We used to get railcars in loaded with lead and add it to the gasoline during blending. Older cars without the hardened valve sets love the lead. Cars with hardened valve seats don't need it as Joe mentioned earlier.

Rolf
1966 230SL Auto
1992 300D
1991 FLHS