Re: gap on their spark plugs
Originally Posted by GreaseMonkey
It won't make a difference at all. Stick to what the factory recommends.
1 wk ago I pulled plugs and increased size of gap from .048 to .050. Plugs were looking like they had just been installed a few mi. ago. Recently had TSB 18-031-07 performed and I was impressed w/the results. Lower cruise rpm, even better and smoother acceleration, and better mileage. Around town now I can accelerate @ 1350 rpms. Before TSB it took at least 1550 rpm to accelerate even the slightest amount from 25 to 30 mph. 1st tank after regapping plugs jumped to 29.3 mpg.
When I looked up info on APP5224 plugs I saw that they fit a Cadillac CTS and the recommended gap for that application was .050. I decided to try it and could not notice any detrimental changes to the way the car starts or runs. I saw on the internet that if a coil on plug system does not overheat then the gap is not too large. I took the car for a 1/2 hr. run on the highway @ 70 mph and all 4 coils were cool to the touch. Imho .050 gap is not too large. Could it be made larger? Maybe, but @ over 29 mpg almost all city/suburban driving I am happy compared to what other 2.0 CVT owners are reporting for gas mileage.
Now that temp has cooled down to 20 deg. in the am here in E. Mass. perhaps the.050 gap may be a little large. Caliber now cranks for a second or two first start in the am , but still starts instantly after the first start. Larger gaps do help with mpg. The reason the factory gaps the plugs at .040 is to allow the plugs to wear without needing to be replaced right away. Larger gap and APP5224 Autolite double platinum plugs do not automatically mean more power, but they do provide smoother response to small throttle inputs while cruising at speeds above 20 mph.
Bright Silver SXT 2007, Security Group, CVT, Sunroof, Fog Lamps, 6 CD Changer, SIRIUS Radio,Alloys
Last edited by vmfa323; 11-29-2008 at 12:18 PM.