[Godders]

I bought a MV7201 Fluid Evacuator Plus (http://www.mityvac.com/pages/products_fee.asp), shop around and you should pay a bit less than £100 delivered

There's a few reasons why I chose this over the Pela extractor, and any other :

• The capacity (8.5l) allows for the '8 to be drained in one go without the need to empty several times for each drain.

• The external vacuum pump is not likely to get contaminated (the Pela has it internal to the main tube)

• There is a small 'foot' on the base that can be lodged between the tyre and floor to stop it falling over as they get top heavy when full and could be knocked over

• The build quality of the Mityvac seems better

I was always sceptical about these devices and bought it to do an interim oil and filter change between services. On my first few changes I did remove the sump plug on all the cars I did and got no other oil out of the sump, plus I did the reverse experiment and drained from the sump plug and managed to get more out with the Mityvac, though it was a very small amount.

I've now done several changes on numerous cars and found changing oil, and filter, is now a breeze and takes significantly less than an hour and does not requires the jacking up of the car, removing the belly pan etc. Disposal is a breeze too as you can pressurise the cylinder and pump it back out. To clean, once empty just suck in some brake cleaner and give it a swirl around and pump out the waste.

My theory is, many cars now have oil filters that can be replaced from the top of the engine so the sumps are probably engineered so you can 'change from the top' and to have the lowest point below the dipstick tube to get most of the oil out, also with modern oils there shouldn't be too much sludge or contaminants in the engine.