Just finished my usual 800 mile highway run in my 1999 expedition with QSUD 10w30 and noted the oil level only dropped one sixth of a quart. The expy has about 177k miles.
Prior to this after the factory fill was drained the expy has only seen mobil 1 from 5w30 to 0w40 to my blend of 0w20ep/15w50. With any M1 it uses about 1 quart per 700 miles over the same route taken with qsud.
I was hesitant to use qsud but am really happy that i did.
Fuel economy same or slightly better with qsud.
Coolant temps also about same. 190 to 203 f with both qsud and m1.
Prior to this after the factory fill was drained the expy has only seen mobil 1 from 5w30 to 0w40 to my blend of 0w20ep/15w50. With any M1 it uses about 1 quart per 700 miles over the same route taken with qsud.
I was hesitant to use qsud but am really happy that i did.
Fuel economy same or slightly better with qsud.
Coolant temps also about same. 190 to 203 f with both qsud and m1.