Most gas engines tody have 7500 to 10000 mile change intervals . No
diesel machanic will ever reccomend you go more than 5000 on a diesel -
epecially if you tow frequently with it.
Diesel engines run hotter ( a lot hotter) and break oil down faster -
that's why you have an oil cooler. . I would never go more than 5000
between oil changes no matter what. I normally go 4000 although Ford
reccomends if I remember 7500.
A gas engine takes about 5 - my diesel takes 14 quarts almost three
times as much.
The oil filter on a gas engine cost a few bucks on my diesel truck it
cost about 20 bucks. The fuel filter on a gas engine needs changed
about every 50 thousand miles and cost a few bucks. The fuel filter on
my diesel has to be changed every 15,000 and cost about 20 bucks.