I have installed a set of the new Paltinum +4 in my 85 190E. It seems to run better than the copper core plugs that were in it when i bought it. I have heard some negative things about using platinum plugs in MB's. Some have said that only the older ones won't run right with platinums, but none could give me a definate reason as to why. Has anyone heard the same and what plug would you recommend? Thanks in advance!