What spark plugs would the Techs recommend:

1. Copper Core
2. Platinum Core

Stay with original equipment design. I believe that's copper core plugs for your car.

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95 E320 Cabriolet, 159K

Search the past forum threads. I think you'll see there are some varied views on copper vs. platinum vs. iridium vs. dilithium crystals, etc.

There is no such thing as platinum core. The two basic design architectures are copper core - nickel electrode, and copper core - platinum electrode. Some platinum electrode plugs are considered "high performance" and others are "long life". The later typically are "double platinum" with a platinum button welded to the ground electrode.

Mercs from your era typically use non-resistor plugs, and resistor plugs might not perform as well. Most manufacturers do not offer proper non-resistor plugs for Mercs, but Bosch does, and they are usually not too hard to find.

Consult your owner's manual and use the recommended Bosch Super plugs for your engine. These are copper core nickel electrode type. They should have a list price of no more than $2.50 each and should nominally last for 30K miles.

My 2.6 calls for the Bosch H9DC or H9DC0. The OEM plug was the Bosch H9DC0. The "0" suffix indicates a heavy duty electrode. They are harder to find and cost more.

Duke

There is a lot of marketing hype about spark plugs. As usual, misguided hopes which result just cost us money, and don’t produce real results.

In my testing, the Bosch +4 and the NGK 3’s only advantage is allowing 4, or 3, opportunities for a single spark path, the one better path at any given time get the nod. That may explain some good impressions about the plug, (i.e., a spark path more easily presents itself) but I ask, at what cost? …and why? …when far better spark technology is available. This technology makes marginal most of our mussing about plugs. However, I would recommend NGK because they have the finest ceramics, are well made and are not too costly.

MB spark is amongst the highest energy in the first place. However, ever seen most sparks at the plug? Add the effect of compression, and things seem even less impressive. The bottom line is that we are trying to affect as many air-fuel molecules at one time to effect a positive ignition each and every time. Nothing more, nothing less.

The way to affect the most air/fuel molecules is with increased energy, not increased duration. A stringy spark lasting a longer time still affects only a fraction of the air/fuel molecules than the massive plasma sphere produced with a peaking capacitor. It ignites the leanest and richest of mixtures, and one does not have to use costly spark plugs with multiple spark pathways. Install DirectHits and stop worrying about the performance of your sparkplugs.

i have a 190e-1993 but 1.8 litre uk spec car.

i can confirm that the spark plugs are bosch h7dco-or beru 14k-7duo or champion s9ycc.-this is for a uk car.-so i guess it would be best to go for bosch h9dco as per some of the other responses you have had so far from the u.s.

you will probably be able to get the bosch plugs from the fastlane link at the top of this website,and be able to see exactly what you are buying as they have the pictures as well.