From the time my car is up on ramps to the time it is off the ramps is usually about 20 minutes. I pull it up on the ramps, put the new oil filter and new oil in front of the car, pull the plug, wait until it turns from a stream to a drip, plug it up, pre-fill the filter as much as it will allow without pouring out when I put it on and attach the filer, fill the engine with the new oil, wait about a minute for the oil to hit the bottom of the pan, put the oil cap back on, start the engine and as soon as the oil pressure light comes off, I pull off the ramps, idle it in neutral for about a minute while the new oil circulates and while I check for leaks and put the ramps away and I take it for a 5 minute drive, come back shut it off for a bit and verify the level is correct. I don't take more than an hour from the point that I decide to start working to the point that I am on to better things.