75 TS Plugs?

[GTVeloce]

Hi all

I have just picked up 8 new plugs for the TS. I ordered Bosch FR 5 DC which is what I have used before. After I picked them up I noticed that some were FR 5 DC and some were F 5 DC. I have tried to do some research as to what the differences are and have not had much luck. Externally they appear the same and they should be the same heat range. The gap is 1mm different but that is easily resolved. Has anyone had any experience with the F 5 DC plugs? I searched the Bosch catalogue and they don't mention F 5 DC for any cars!

If there is no other differences then I'm happy to run them but would rather find out before I stick them in the car.

Thanks
Julian

[Darryl]

The R is with suppression resistor. It shouldn't matter much but it wouldn't hurt to try to be consistent (ie if you have 4 of each it would be good to run 1 R plug and one non-R/cylinder).

[GTVeloce]

Thanks Darryl. I got searching for info regarding suppresion resistors and came up with the following page which was quite interesting;
http://www.ngksparkplugs.com/techinfo/spark_plugs/faq/faqresistor.asp

I think I will take the non R plugs back and get the ones I want.