Dad and Son the mechanics

Wife calls me to tell me what a wonderful meal she has made and to hurry home. Can't believe it, my wife has cooked me a hot meal for a change. 5min later as I am driving home I am told not to come home but to now help the 18year old who's car is stranded on the roadside. I went over to my parents house where Joe was to give me an in depth problem description. Something about it took awhile to warm up and it drove like in 3rd gear while in 1st. He also had let the battery go mostly dead but was able get it started. Me being mechanically inclined and my son have taking 2 course of advanced car mechanics were looking at the possibilities, alternator, fuel pump or maybe a clogged fuel filter. Grandpa ever once in awhile from his chair would pipe in, "Did you try putting gas in it?" Joe countered he only had 150mi on a 350mi tank so that couldn't be it. After 30 min of diagnose, I called the tow truck anyway but to humor my dad we took some gas. As we are waiting for the tow truck, I told Joe to throw some gas in to kill some time. 2 min later his car fires to life and he speeds off. 2 hours of trouble shooting and a missed hot meal. I really would like to know what they're teaching in that mechanic school other than how to figure accurately how much your gas tank really holds, 11.31gal in this case. sigh