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Spark plugs poser

Question : I drive a 1996 Honda Civic SO-4 manual non V-tec. The standard spark plugs are NGK BCPR5E-11. I changed to NGK BKR5E-GP and the fuel consumption suffers. Why is this so?

Previously, my Wira 1.6XIi did not have this problem, and the Daihatsu Ascent 1.6, Perodua Kelisa and Kenari are OK with that plug. Does the Honda Civic have a special-design combustion chamber? What is the meaning of the alphabets beside the number of the spark plug?

Two-stroke motorcycles and some super bikes are using aluminium block, whereas some use only cast iron block. My Honda and the other B-Series engines are aluminium block. What are the pros and cons of aluminium and cast iron blocks?

Answer : The BCPR5E-11 is interpreted as:

B - 18 mm thread diameter

C - 5/8" hex socket size

P - Projected insulator type

R - Resistor type

5 - Heat range (2 is hot, 10 is cold)

E -19 mm thread reach

11 -1.1 mm plug gap

The difference between the BCPR5E and the BKR5E is shown by the K letter which indicates that it has a projected tip and that may be the reason for the drop in fuel consumption. The projected tip may be moving the igniting point of the air-fuel mixture such that you are not getting complete combustion and a loss in power, and this is affecting fuel consumption. This is the only explanation I can give assuming everything else is the same.

Many years ago before technology improved for the casting of thin-walled aluminium castings, it was normal to use cast iron blocks because the technology was there and cast iron was cheaper. However, today you will notice that except for heavy duty diesels, almost all engines are cast in aluminium.


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