Okay so we needed a pump to drain the oil out of a boat and this one had the best reviews and it actually proved itself. We didn't warm up the motor so it took longer to drain but it did a heck of a job, got all the oil out, wait time was probably around 20 minutes because the oil was cold. It did not overheat at all. The flow was a little weak but better slowly but surely!

Bought this to change the oil (7 qts) in my 2016 Genesis.
I don't know what other people are complaining about.... this isn't THAT slow..
Wish I would have timed it, but after reading the "complainers" reviews I was pleasantly surprised..
I did find that the short clear connecting tube (also works as a sight glass to see you have flown) will collapse under vacuum... I cut it to just long enough to make a snug connection, and have just about 1\4 inch of gap between the tubes.
I used the nylon tube down the dipstick. Take the time to straighten it out...use a hair drier\heat gun (or carefuly over the gas flame on the stove lol}
Also, be sure to have a slight angle cut on the end, so it's not down flat sucking against the bottom of the oil pan.
I do agree, the cables could have been a little longer for my car, but I made it work.
Use your jumper cables.
Also, be sure to drive the car around the block and couple times to thin the oil down...
I ran it into a gas can that I had in the garage... I wasn't used to needing much more than a milk jug .
Then used the spout to pour it into the jug\bottles the new oil came in.

Completely happy with my purchase!
Didn't have to run around sourcing all of the other parts...

Worked perfectly to pull the oil out of 2012 Chevy Sonic. This little pump extracted all of the oil in about five minutes. The flexible tube works best as the copper tube can't bend enough to get to the bottom of the oil pan.

Pump worked great. Suggest warming engine to roughly 120*F to thin oil and enable faster pumping. I connected refrigerator ice maker tubing (8 mm ID hard wall tubing) to the flexible/soft feed line tubing that came with the pump. The hard 8mm water tubing (also commonly used for pneumatic controls) slid right down my oil dip stick tube down to bottom of my oil pan in my VW. It pumped out 6 Qts in about 10 minutes. Really slick. The battery connector wires could be a bit longer for some cars but reached my battery fine. I mounted on a small board, kept the tubing attached and intend on using for all my oil changes. Hopefully this it will continue working for years to come. You never know with a cheap little pump like this. It appears to be a single diaphragm pump run off a tiny cam on the 12 V motor. Should try to find a replacement diaphragm while pump is still being made

The pump itself sounds horrible, like it's full of rocks, but it works very well. I used it to transfer diesel fuel from an underground tank through about 50 feet of 3/8" copper tubing. Given that scenario, it would pump 5 gallons in about 20 minutes. There is no mechanical on/off switch and the intake spout works well with 3/8" tubing.