[g2BMW]

Not sure when the plugs were changed as I bought this car recently. But changed them anyways as the mileage was at 73k, got these
NGK (5992) ILZKBR7A-8G Laser Iridium Spark Plug,

The car regained quite a bit of power, the exhaust sounds deeper (not sure why) and I like it, but my mileage dropped a 1 or 2 mpg's!!! Any reason why?

[Knonsense]

right foot problems.

there's a thousand things that'll affect mpg's. most likely explanation is that you're driving incrementally harder because of the increased power and tone. could be that you just now turned on your AC, or otherwise drawing more power thru the alternator. could be you lost a few psi's in your tires. could be you drove with your windows down more often than windows up. hell, if you drive with three pedals, your shift point could've gone up 200 rpm's.

1-2 mpg's ain't a thing when you and your car are just getting to know each other.

[hetzle]

Originally Posted by Knonsense

right foot problems.

there's a thousand things that'll affect mpg's. most likely explanation is that you're driving incrementally harder because of the increased power and tone. could be that you just now turned on your AC, or otherwise drawing more power thru the alternator. could be you lost a few psi's in your tires. could be you drove with your windows down more often than windows up. hell, if you drive with three pedals, your shift point could've gone up 200 rpm's.

1-2 mpg's ain't a thing when you and your car are just getting to know each other.

This man is 100% correct, a 1-2 MPG discrepancy is impossible to pinpoint

[g2BMW]

Originally Posted by Knonsense

right foot problems.

there's a thousand things that'll affect mpg's. most likely explanation is that you're driving incrementally harder because of the increased power and tone. could be that you just now turned on your AC, or otherwise drawing more power thru the alternator. could be you lost a few psi's in your tires. could be you drove with your windows down more often than windows up. hell, if you drive with three pedals, your shift point could've gone up 200 rpm's.

1-2 mpg's ain't a thing when you and your car are just getting to know each other.

driving hasn't changed at all except to feel the new power initially. I didn't set the gaps on the plugs, would that make any difference. Technically it shouldn't have cuz there are no weird rpm drops or misfires or any strange idle.