The oil doesn't stay in the filter after engine has been shut off, this causes engine oil deficiency at start up next time for a short time,eventhough there is an anti drain rubber ring in the filter, but still, the oil inside wouldn't be contained long, in contrast the upper facing ones like Hondas are always full of oil, so whenever you start the car again, the oil needs no time to fill the filter first in order to get to the engine, minimized the engine dry run time.