I gave them another 2 weeks, just to be certain that my mileage drop wasn't a mis-calculation. It wasn't. Highway mileage dropped from 29mpg to 26-27mpg. That can be expensive in the long run. So I went down to the local Bosch supplier and got a set of standard Bosch Super plugs & installed them last night. Will report on any mileage change with these.
Collin KC8TKA E320/97
I had exactly the same issue with my 1989 190E. Luckily I saved the receipt and got a full refund. Bosch copper cores seem to work best in that car.
This is a prime example of false advertising [in a way]. When you go to a auto parts store to get spark plugs, the Bosch catalog will say those are recommended by the manufacturer..... but nowhere does it say WHAT manufacturer!!! It is the spark plug manufacturer, in this example Bosch BUT they ALL do it!!. Not the automobile manufacturer. Mercedes says Bosch super copper core ONLY.
Mercedes NEVER ever recommends those Platinum 4's.
This can not be wright.
MB comes out of factory _with_ platinum plugs in it and you tell us they don't recommend them.
Reg: Harri
This can not be right.
MB comes out of factory with platinum plugs in it and you tell us they don't recommend them.
Reg: Harri
It depends on the engine, this owner has an older engine for which the old plug was specified - and that specification was never changed, despite new spark plugs being available.
I suppose E320/97 is with M112 engine and it is specifyed with platinum plug.
Reg: Harri
The 97 factory plug, as I understand it, was a standard Bosch Super.
I went into WalMart yesterday and was really surprized to see Bosch Platinum nd Platinum 2 on the shelf, for my car! (None of the parts stores I went to ever mentioned standard Platinum plugs.)
Collin KC8TKA
The real issue is two-fold. The Bosch +4 are resistor plugs, which the original coppers were not and so resistance was built into the plug wires in the older engines. So, using the new plugs in the older ingition systems is going to affect performance. Second, the spark from the +4 is not the optimum pattern for the older engines. The newer cars come with the newer plugs to optimize plug life and have the accompanying electronics to support it.
I can't imagine a '97 is considered and "older" engine. Are not the plug wires carbon filament? Aren't all current modern automobile plugs resistor plugs?
Collin KC8TKA
Which is it older M104 (I6) or newer M112 (V6)?
Reg: Harri
I've always wanted to know, is it an actual 1 or 2k resistor, or is a graphitic 'wire' used which has been made to have that resistance ... if I'm clear ... I hope so :-)
cheers
No, the '97 was the last year of the 104 straight six and its old Super plugs. I own a '97 and found no difference between the original Bosch and the new Bosch Platinum 2 plugs.
My earlier point was that the old Super plugs were specified when the car was built - fine - but is that specification ever reviewed and updated for newer technology? Or is the technology frozen in time?
Solid wire wires with a 1K or 5K resister on the end. Also the rotor has 3.2K built into it.
That is ALL the resistance that is required. Adding resister plugs is a no-no.
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