Changed spark plugs.... MPG went up?

[chrisbruck]

Changed the original iridium spark plugs on my '04 LC at 124k. All looked fine and clean except 1 plug was finger loose. The coil rubber boot was more of a burnt brown than the grey color like the rest so I'm guessing a little compression was escaping. Used replacement factory Toyota plugs. Truck ran great before and I only changed to follow the regular maintenance schedule.

So, now with the new plugs I swear my MPG's have gone up 1-2 points. Is this all in my head or real?

Like I said, truck ran great before, even with the so called loose plug. Ran smooth and never a CEL.

Other's experienced this MPG gain with new plugs?

 

[2003lx470]

Recently changed spark plugs on my 03 LX 470 with 70K miles. I haven't notice any change in gas mileage but I am sure my engine appreciates the change.

 

[bdac]

I need to change my plugs. On a similar note I could swear that the engine runs smoother after an oil change.

 

[jemsec]

It even runs better after a good wash, wax and a little tire cleaner. Might add 2-3 MPG.