UPDATE: For those that don't want to read through the 2348972347892 pages of this thread, we have found that the following plugs seem to work best in the 1.4-Liter engines:
-BKR8EIX-2668 (iridium plugs), expect ~10-15k regaps on these, ~40-50k overall life.
-BKR7E-4644 (nickel/copper plugs), expect 15-25K out of these plugs, with a regap or two required at 5-8k intervals on stock tune.
-FR7BHX-S (ruthenium) - this is the latest recommendation for a combination of long life and drivability.
Set initial gaps @ .028". Higher gaps will start to blow-out as the gaps increase.
So for what it's worth, some of you may remember that I was saying I had hesitation that felt like timing pull, even on 93 octane during winter months. I believe I got that one taken care of with a new stock ECU tune from Chevrolet, as for the most part, it behaved much better after that.
However, with the AC on fan speed 3, and especially 4, on a hot day (85+), and even sometimes just randomly when it's not that hot, I'd feel a strong timing pull from 1850-2750 RPM...jerky acceleration and the car just felt...slow. Pinging right off the knock sensor, about 3-4 times per gear under acceleration. With the AC off, it's fine unless I'm sitting at a light for a while.
I ordered the copper NGK version of the same heat range plug that's in the car (BKR7E) and dropped them in today. Perfect day to test - lots of traffic, lots of stoplights, AC on fan speed 3/4, and 94 F outside.
Once the ECU "adjusted" after a few seconds, I could not get the car to jerk WHATSOEVER. Very happy. Acceleration is smooth from a stop all the way up to 5500 RPM, and the car drives like what I feel like it was made to drive like.
I don't know why this made a difference, other than my experience that turbo cars do not like platinum plugs and perhaps iridium have the same effect on them. The old plugs look like they're burning just fine and are clean.
EDIT:
Many of us have found that the .035" gaps are a little bit optimistic - our cars will start to blow out after not too long as the gaps grow. I'd recommend starting in the .028-.030" range. Check your plugs again after 10,000 miles and readjust.
![Image]()
![Image]()
Old iridiums
-BKR8EIX-2668 (iridium plugs), expect ~10-15k regaps on these, ~40-50k overall life.
-BKR7E-4644 (nickel/copper plugs), expect 15-25K out of these plugs, with a regap or two required at 5-8k intervals on stock tune.
-FR7BHX-S (ruthenium) - this is the latest recommendation for a combination of long life and drivability.
Set initial gaps @ .028". Higher gaps will start to blow-out as the gaps increase.
So for what it's worth, some of you may remember that I was saying I had hesitation that felt like timing pull, even on 93 octane during winter months. I believe I got that one taken care of with a new stock ECU tune from Chevrolet, as for the most part, it behaved much better after that.
However, with the AC on fan speed 3, and especially 4, on a hot day (85+), and even sometimes just randomly when it's not that hot, I'd feel a strong timing pull from 1850-2750 RPM...jerky acceleration and the car just felt...slow. Pinging right off the knock sensor, about 3-4 times per gear under acceleration. With the AC off, it's fine unless I'm sitting at a light for a while.
I ordered the copper NGK version of the same heat range plug that's in the car (BKR7E) and dropped them in today. Perfect day to test - lots of traffic, lots of stoplights, AC on fan speed 3/4, and 94 F outside.
Once the ECU "adjusted" after a few seconds, I could not get the car to jerk WHATSOEVER. Very happy. Acceleration is smooth from a stop all the way up to 5500 RPM, and the car drives like what I feel like it was made to drive like.
I don't know why this made a difference, other than my experience that turbo cars do not like platinum plugs and perhaps iridium have the same effect on them. The old plugs look like they're burning just fine and are clean.
EDIT:
Many of us have found that the .035" gaps are a little bit optimistic - our cars will start to blow out after not too long as the gaps grow. I'd recommend starting in the .028-.030" range. Check your plugs again after 10,000 miles and readjust.
Old iridiums
