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Why do you want a colder plug? That is old school chevy tuning stuff.


I guess partly because I'm an old school Chevy tuning guy.

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The VR4 runs the same plug as the NA engines.


Not exactly. It does run the same heat range as the sedans. The Montero was spec'd with a heat range 5 and the sedans were spec'd with a heat range 6 which is a colder plug than the Montero.

BPR5ES-11 = Montero

BPR6ES-11 = Diamante SOHC

BKR6ES-11 = Diamante DOHC
BKR6ES-11 = 3000GT non-turbo
BKR6ES-11 = 3000GT VR-4 turbo

In NGK terminology, the following are the codes

1st Character
B = 14mm hex size

2nd Character
P = projected insulator type
K = 5/8" projected tip

3rd Character
R = resistor type

4th Character
2 = hot -> <- 12 = cold

5th Character
E = 3/4" thread reach

6th Character
S = standard center electrode type

7th (and 8th if used) Character
11 = .044" gap

I agree that the heat range 6 plug with the standard gap should work fine. I did get detonation in the prior engine with heat range 5 plugs, but that wasn't the only issue. In this case, I was trying to get some extra insurance until the tune was finished..... but too much insurance isn't always a good thing.

Frank