I change mine around every 5,000 miles. Seems to have worked out for the last 512,000 miles or so.

 

Would a time frame also enter into the equation? I'm only doing about 5K per year.

 

That's about what my wife does. I change hers once a year.

 

Mine is also 5-6K per year on the truck. Change oil in the fall and store for winter.

 

Every 3 to 5k because I can. Motocraft oil. the Sumitomo or fumitomo drain valve whatever the name is, works like a champ as well.

 

my '97 every June
my "99 service truck every other June
my '97 my father drives every other June
my 2000 excursion every June
my '95 that my Son drives every June
I have run my '97 up to 15,000 miles and the report said to re test in 5,000 miles, my '97 almost always tows heavy. pic in sig is 27,000+ lbs hauled 2 times a year 500 miles in all mountains.
I run rotella T6 in everything

also have a '91 wrangler
'80 CJ7
'53 MJ
'80 K10 sport
my son also has a toyota
my father has 2 other trucks
so nothing gets too many miles on it