Lost MPG after Tune Up on Honda VX

[SuperVX]

Hi Everybody,

Got a odd ocurrence with my VX. After a tune up of

• Mobil One 5w-30 oil change
• Fuel filter
• Cap and rotor
• Spark plugs (NGK ZFR4F-11)

My MPG DROPPED 7 Miles per gallon or about 15%
(From Nearly 50mpg to 43mpg)

What on earth has happened? I thought I'd see a little increase not a large decrease.

Please offer some insight if you can

Thanks