Back when i got my 98 Stang, with 100000 miles back in August, i immediately changed the wires, plugs, and gave it a cold air intake. I used bosch platinum 1 plugs and just regular old wires that were 20 bucks. I'm at 105000 miles now.. I get pretty crappy mileage... i've never ran it to empty, but at 210 miles the gauge will be right above empty, doing lets say 80 percent city driving. (on a side note, does my car have a gas light? hahaha..)Few questions.1- What spark plugs are optimal for good fuel consumption and a smooth ride? 2- Should i dish out more money for "performance" spark plug wires, or just save it?3- Besides stuff like the plugs, wires, air filter and PCV valve, what else should I replace? Just got sweet new tires btw. Thanks!

Cap and rotor also. Bosch platinum is a good plug.Sounds like you did a good job already though. Run thicker oil in the summer 15/40 or 20/50 castrol GTX,my personal preference,and a federated oil filter.Have the tranny serviced as well. See what you get from there.Run Sunoco or Hess gas only depending where you are from if they have them in your area.

You might want to replace the fuel filter some times they wont show signs of be plugged up but you can bet your ass that with 105,000 miles it wouldnt hurt to change it i bet you will see a difference.