New spark plugs and WORSE gas mileage...
09-12-2005
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New spark plugs and WORSE gas mileage...
Recently I put in some Denso Iridium IK20's in replacement of my stock spark plugs. The car does perform more smoothly, however my gas mileage has decreased about 3-4mpg instead of increasing by this number. I'm pretty sure I installed the plugs correctly.
Possible problems: I got some new tires on a day after I put the spark plugs in. 205/40/17 --> 215/40/17. I don't think the small amount of extra rubber could cause my mileage to decrease THAT much, could it? I run super huge sidewall tires on my stock steelies (195/65/15) and my gas mileage is usually about 32-34 still. Before I got my new tires and spark plugs in I got 32-34mpg also. When I calculated my fillup last night I only got 29.
Any ideas?
Possible problems: I got some new tires on a day after I put the spark plugs in. 205/40/17 --> 215/40/17. I don't think the small amount of extra rubber could cause my mileage to decrease THAT much, could it? I run super huge sidewall tires on my stock steelies (195/65/15) and my gas mileage is usually about 32-34 still. Before I got my new tires and spark plugs in I got 32-34mpg also. When I calculated my fillup last night I only got 29.
Any ideas?
09-12-2005
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Tire Pressure (Hot) is at 35psi.
I'm running 17's. But I'm comparing the gas mileage to when I had the 205/40/17's.
Maybe I screwed in the spark plugs too tight, or too loose...
Tire Pressure (Hot) is at 35psi.
I'm running 17's. But I'm comparing the gas mileage to when I had the 205/40/17's.
Maybe I screwed in the spark plugs too tight, or too loose...
09-12-2005
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ha finally it gets proven. Use stock double platinum! If you checked tire pressure (should be 30psi cold, never measure hot), and made sure the plugs are torqued (with a proper torque wrench) to 13ft/lbs, then its the plugs that are the problem. I've gotten my highest mpg using stock plugs.
09-12-2005
#6
heee....gearbox seems to be happy with it. LOL
well, again, my .02..
first, re-torque the plugs to 18N-m.....
then, check ur tire pressure in cold morning, adjust it to....31psi Front, 30psi back....
ACTUALLY....i did these...and seems like it's getting a better mileage now....and less engine noise at 3000~4000 rpm.....
before, it was a bit "growling" at that range..
well, again, my .02..
first, re-torque the plugs to 18N-m.....
then, check ur tire pressure in cold morning, adjust it to....31psi Front, 30psi back....
ACTUALLY....i did these...and seems like it's getting a better mileage now....and less engine noise at 3000~4000 rpm.....
before, it was a bit "growling" at that range..
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