Put this in general because my comments could apply to all variants and for those who want to boldly go where no hand has set foot! In my case I have been researching for the best plugs to put in my 55. To be frank, there appears to be huge lack of information on plugs but the fundamentals I need are:
Thread 14mm
Thread pitch 125mm
Reach 19mm 3/4 inch
Then Material, Gap and of course heat range etc.
I know most of us would rely on our retailers advice and the go to plug for M113 seems to be the NGK IFR8D10 which seems to be a very good Iridium electrode plug. Outside of that the confusion arises however because the retailers rely on the info from their suppliers and as I have found that what is compatible for one engine thru some sellers is not through others. Then there is the Part No fiasco whereby some manufacturers appear to have up to three different part numbers for the same plug. For example, the Bosch Double Iridium goes by the title 0242236599 or 9603 or FR7KII33X no less! Then there is the all important heat range. What NGK list as their 6 for the same heat Bosch list as 7 and none of the other manufactures seem standardised. Finally there is the price which can range from anything between 8 and 20 GBP for the same part numbers!
As we know, Iridium lasts longer, up to 100k miles apparently and it seems that Bosch have gone one step further with their Double Iridium plug where both the electrode and the Ground have Iridium elements. In fact they even do the same plug with what they call Pin to Pin whereby it has a small Iridium pin set into the Ground... but these do not appear to be available yet.
Getting info from Bosch UK or Europe is futile and I just got referred to a Bosch workshop or Eurocarparts who don't even supply their wonderful Iridium plugs! Wherever you are in the World therefore, an online search will glide you to the the USA (hurrah) portal! Bosch US only list one Part No for the SLK55AMG which is their super duper Double yummy Iridiums, the ones the one the UK suppliers do not recommend. Furthermore the ones the UK suppliers do recommend, Bosch do not! Go figure..?
So, who do we believe? In actual fact, all the plugs that both the retailers and Bosch list are identical in dimensions and the only difference is one has a heat range of 6 and the other 7 so it could be fuel grade related but you would imagine Bosch Worldwide would indicate a different spec for a different market. That said, so long as you are using premium fuel 99 or 97 RON I believe the ECU adapts the timing accordingly. Be interesting to hear what you supercharger guys use?
Here are a couple of links for anyone who's interested
www.boschsparkplugs.net
PS. Has anyone found a European or UK supplier for the famous Spark plug wire removal tool who will not charge an arm and a leg for shipping. And yes, I know I can bend a 17mm spanner
Thread 14mm
Thread pitch 125mm
Reach 19mm 3/4 inch
Then Material, Gap and of course heat range etc.
I know most of us would rely on our retailers advice and the go to plug for M113 seems to be the NGK IFR8D10 which seems to be a very good Iridium electrode plug. Outside of that the confusion arises however because the retailers rely on the info from their suppliers and as I have found that what is compatible for one engine thru some sellers is not through others. Then there is the Part No fiasco whereby some manufacturers appear to have up to three different part numbers for the same plug. For example, the Bosch Double Iridium goes by the title 0242236599 or 9603 or FR7KII33X no less! Then there is the all important heat range. What NGK list as their 6 for the same heat Bosch list as 7 and none of the other manufactures seem standardised. Finally there is the price which can range from anything between 8 and 20 GBP for the same part numbers!
As we know, Iridium lasts longer, up to 100k miles apparently and it seems that Bosch have gone one step further with their Double Iridium plug where both the electrode and the Ground have Iridium elements. In fact they even do the same plug with what they call Pin to Pin whereby it has a small Iridium pin set into the Ground... but these do not appear to be available yet.
Getting info from Bosch UK or Europe is futile and I just got referred to a Bosch workshop or Eurocarparts who don't even supply their wonderful Iridium plugs! Wherever you are in the World therefore, an online search will glide you to the the USA (hurrah) portal! Bosch US only list one Part No for the SLK55AMG which is their super duper Double yummy Iridiums, the ones the one the UK suppliers do not recommend. Furthermore the ones the UK suppliers do recommend, Bosch do not! Go figure..?
So, who do we believe? In actual fact, all the plugs that both the retailers and Bosch list are identical in dimensions and the only difference is one has a heat range of 6 and the other 7 so it could be fuel grade related but you would imagine Bosch Worldwide would indicate a different spec for a different market. That said, so long as you are using premium fuel 99 or 97 RON I believe the ECU adapts the timing accordingly. Be interesting to hear what you supercharger guys use?
Here are a couple of links for anyone who's interested
Bosch 9603 FR7KII33X 0242236599 Double Iridium Spark Plug
$8.17 Bosch 9603 FR7KII33X 0242236599 Iridium Spark Plug - Same Day Shipping. Free Returns. PayPal Accepted. Secure Online Ordering. Est. 1969.
www.boschsparkplugs.net
PS. Has anyone found a European or UK supplier for the famous Spark plug wire removal tool who will not charge an arm and a leg for shipping. And yes, I know I can bend a 17mm spanner
