Spark Plugs gapped too much
#1
Driver School Candidate
Thread Starter
Spark Plugs gapped too much
So my 2012 IS350 that I recently bought has 56k miles and I decided to do the plugs that make the spark in the engine that makes the noise. So I was looking through threads and somehow came to the conclusion by someone’s post that seemed legit, or at least legit enough, that the gap was 0.039. The original plugs that I removed were gapped to 0.039. The OEM plugs that I bought off amazon were 0.043.
So I went ahead and gapped the iridium plugs to 0.039 and put the plugs in. Car started up, ran fine, no problems on the test drive, etc.
Came home, had the idea to check the owners manual to make sure. Bam... 0.043. So my question is...
Will having the plugs gapped to 0.039 as opposed to 0.043 really make that much of a difference? Gas mileage? Power?
Im new to the N/A scene but I know with tuning boosted engines it makes a massive difference. Any input would be great.
So I went ahead and gapped the iridium plugs to 0.039 and put the plugs in. Car started up, ran fine, no problems on the test drive, etc.
Came home, had the idea to check the owners manual to make sure. Bam... 0.043. So my question is...
Will having the plugs gapped to 0.039 as opposed to 0.043 really make that much of a difference? Gas mileage? Power?
Im new to the N/A scene but I know with tuning boosted engines it makes a massive difference. Any input would be great.
#2
Lead Lap
iTrader: (13)
So my 2012 IS350 that I recently bought has 56k miles and I decided to do the plugs that make the spark in the engine that makes the noise. So I was looking through threads and somehow came to the conclusion by someone’s post that seemed legit, or at least legit enough, that the gap was 0.039. The original plugs that I removed were gapped to 0.039. The OEM plugs that I bought off amazon were 0.043.
So I went ahead and gapped the iridium plugs to 0.039 and put the plugs in. Car started up, ran fine, no problems on the test drive, etc.
Came home, had the idea to check the owners manual to make sure. Bam... 0.043. So my question is...
Will having the plugs gapped to 0.039 as opposed to 0.043 really make that much of a difference? Gas mileage? Power?
Im new to the N/A scene but I know with tuning boosted engines it makes a massive difference. Any input would be great.
So I went ahead and gapped the iridium plugs to 0.039 and put the plugs in. Car started up, ran fine, no problems on the test drive, etc.
Came home, had the idea to check the owners manual to make sure. Bam... 0.043. So my question is...
Will having the plugs gapped to 0.039 as opposed to 0.043 really make that much of a difference? Gas mileage? Power?
Im new to the N/A scene but I know with tuning boosted engines it makes a massive difference. Any input would be great.
#3
Lexus Test Driver
iTrader: (2)
Because they are none wearing plugs, over the course of 60,000 mi it is likely it would get a better burn and slightly better fuel economy if at spec. That said, unless you checked all of them and set them, even plugs we pay a premium for (think pre-gapped), I've found them all over the map. Like from .037 to .045".
Rule is check and adjust them as needed as out the box has variability.
Rule is check and adjust them as needed as out the box has variability.
#4
Driver School Candidate
Thread Starter
Well I drove around for a day with them at 0.039 and it was a slight improvement. Definitely more pep and low rpm and smoother than before.
I then took out all the plugs and gapped them to spec, and WOW, huge difference in power, increased fuel economy by 2+mpg, engine was noticeably throatier. I’m glad I took the time to do it. Yea I agree, Increased gap means a bigger arc so more of a burn which explains the power and fuel economy. Not to mention my 56k plugs were worn out. Only takes an hour I encourage everyone to do it! Thanks for the input y’all.
I then took out all the plugs and gapped them to spec, and WOW, huge difference in power, increased fuel economy by 2+mpg, engine was noticeably throatier. I’m glad I took the time to do it. Yea I agree, Increased gap means a bigger arc so more of a burn which explains the power and fuel economy. Not to mention my 56k plugs were worn out. Only takes an hour I encourage everyone to do it! Thanks for the input y’all.
#7
Lexus Test Driver
iTrader: (2)
Gap is supposed to be 0.044".
Engine is happy with TT. Very responsive with new plugs.
The 4705 / IKBH20TT is the same heat range, reach, 0.4mm Iridium tip as the $16 plug. Both are rated at 80k to 100k mi...
Apparently paying an extra $7.50 for plug Gapped at 0.044 is BS! lol?
Engine is happy with TT. Very responsive with new plugs.
The 4705 / IKBH20TT is the same heat range, reach, 0.4mm Iridium tip as the $16 plug. Both are rated at 80k to 100k mi...
Apparently paying an extra $7.50 for plug Gapped at 0.044 is BS! lol?
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