High idle on gas engines is probably to heat up the cat-converters quicker. Hotter cats work more efficiently. Emissions crap.

 

After having new Lariats, XLT's, diesels, 1/2 tons, 3/4 tons (but never an Eco), I ordered 2026 F350 7.3 with STX package and blacked out. It now has only 600 miles on it because I don't drive it in the sloppy salt. 1. I HATE the manual non-adjustable drivers seat. Sits way too high. 2. It's too loud - I mean exhaust loud. 3. Too much road noise. I get it - it's a work truck. I'll search for a thread on seat problem or start a new one as to the best fix.

 

I have owned a 17' lariat f250 with 6.7 ps
a 20 XLT F350 with 7.3 godzilla
a 23 Lariat F350 with 7.3 godzilla
and finally a 26' STX with 7.3 godzilla. The STX is my favorite over the other trim levels. Less stuff to potentially break. I saw where someone was talking about the led modules going out. I turned off my DRL so the "halo" doesn't burn in daylight while driving. I don't drive that much but if I can make something last longer I will.