I just changed the spark plugs myself and i noticed my car is burning more gas than it used to. Is it because of the spark plugs? thanks!
If i installed new spark plugs incorrectly, will it change the fuel effecincy?
If you installed them with the wrong type of plug or the wrong gap on the plug or mixed up the wires or cracked the plugs, using the incorrect spark plug socket (without a rubber grommet in it) or haven't pushed the wires on properly,
YES.
If i installed new spark plugs incorrectly, will it change the fuel effecincy?
It is possible.
If the plugs weren't gapped properly, they might not be creating a hot enough spark to ignite the fuel/air mixture properly/fast enough.
Possibly the plug wires are now damaged. Sometimes damage to the wires is not visible, but still can have a serious effect on the efficiency of the ignition system. If the wires are old, simply moving them can cause damage.
If they aren't tight enough or the threads are stripped, it can cause a leak and loss of compression.
The wrong type of plugs can cause efficiency problems.
I Doubt changing your spark plugs would have any negative effect on your gas mileage. If anything it would be more likely to enhance it. I would suggest getting someone who knows how to install spark plugs properly to make sure you did it properly. Its not a hard job, and only takes a few minutes, but doing it incorrectly can affect many major parts of your engine.
wherever you bought the plugs ask them about the recommended gap for your plugs. In Autozone it shows that on their computer.
I was going to say what everyone here has already said
