i have a 2008 subaru tribeca and in an effort to increase mileage (19.1 mpg) i put in archoil 9100
it has been about 1000 miles and fuel mileage is now 19.3 mpg

this is not scientific

driving conditions have remained the same

engine seems smoother but that does not mean much

not sure if i would buy it again

just my thoughts

Steve