this is the initial test with 5/8'' i.d. heater hose. when the car warms up, the vacuum effect will eventually collapse the hose quite a bit. in the end, i swapped it out to 5/8'' inside diameter reinforced vacuum rated hose. bought a min 10' length from a laboratory supply company. i've drained it 3 or 4 times in about 4k miles in 2018. In total it's strained several ounces of oil - maybe 6oz total over these 4,000 miles. the vacuum hose is clear and no puddling on outlet side.