I was told many years ago "take the car down the freeway and let it rev in a
lower gear then tune it "
So I use  real synthetic oil and do as above besides making sure the coolant
is up to date ,the tyres are at least a recommended pressure or above.It
seems many cars never get a good work out ,and I dont mean thrashing around
,I mean a decent responsible rev out through the lower gears .I am amazed
when neighbours ask me to tune up of fix their cars at the filth around the
motor as well as on the electric's .One guy had a distributor which was so
warn it was backfiring as the rotor his the poles in the cap .He had just
returned from a months holiday ,the trip just there and back was 1800 klms
let alone the runabout mileage, all this with loose gas as in LPG fittings
and a backfiring dizzy.