Doumb Spark Plug Question for Early 911
 

I went to order a set of plugs for my stock 1973.3 (CIS) 911T. In the past I have used Bosch W5DC plugs with good sucess but decided to try the NGK's.

On speaking to the fellow on the order desk, he told me that he thought they were better and I should give them a try. I said ok and they shipped me a set of NGK BP5ES plugs.

Looking at the NGK Web site, I am now confused if the correct plug was selected. This APPEARS to be a much hotter plug than what am am currently using.

Anyone have any comments about this?

Thanks!

I believe Bosch and NGK heat ranges are numbered in opposite directions. Bosch get hotter with higher number, NGK get colder with higher number.

Harry,

The NGK 5's are too hot for your car. I would use 6's.

Steve,

That's what I was afraid of.

The NGK number is in relation to its heat dissipation capability, so the higher the number then the lower CHT. Looks like you already figured this out.SmileWavy

I was looking what tyle of plugs for my '71 911T and at the NKG site the

Standard is BP7ES and the
Iridium IX is BPR7EIX

http://www.ngksparkplugs.com/part_finder/car_truck_suv/results.asp

The same showed also for the '73

http://www.ngksparkplugs.com/part_finder/car_truck_suv/results.asp

I hope these links work.

BPR7's in my 77. i just looked at them yesterday. they looked very good.