should i use oil that suits a gas cars as my car is gas or should i use normal oil. also what type of oil (specs) does ford recommend for me to use in my 1998 EL?

if the engine is in very good nick, no rattle at start up and doesn't drink any oil, then go 15/40, pennzoil make a good gas 15/40 oil, $30.

otherwise go thicker like 15/50 or 20/50.

mines on gas and i use motul 15/50 and ryco filter, did use penrite before but my engine didn't like it, roughness through accelartor pedal and didn't rev freely. the motul has fixed this, but it is not cheap at $45 for 5 litres.

use a gas oil if you can as they have some additives that are required as gas runs hotter.

do a search as oils have been talked about plenty of times before.