i have a 96 civic hx and i was reading and saw that applying lucas fuel treatment could help to your mpg because i have not done a tune up i got it 2 years a go and has 161k so i dont know if i should add a bottle of lucas. if so how much and when do i know i need it?

 

If you haven't done a tune-up in 2 years then it's highly suggested you do. There is no "tune-up in a bottle" as it advertises. There will never be an additive as good as replacing certain components for a tune-up.
Lucas helps your car run smoother & it does give you better MPG..not much..but it does.
getting a tune-up shouldn't cost you too much...but avoiding a tune-up will.

BTW it cost about $5 for the small bottle(add whole bottle to full gas tank) and $11 for the BIG 32oz bottle which will last about a year(if you use 8 ozs every oil change).