I've had two hand pumpers(too slow or too small) then I got small 12v jabsco unit. Still not satisfied with speed. I you want to change piping hot oil think metal tank. The two I've been looking at for some time now (I'm a lazy, cheap SOB) are 6-1/4 Gallon Oil Extractor
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=46149
and Jabsco Porta Quick Oil Changer
http://www.jthelectronics.com/product/31416.html
Spend the money from the get go it's a great tool. Many uses, lawn mowers, snow blowers, rear ends, brake res. etc.....