Under normal circumstances I do the same. Pull the plug Friday night. Let it set till am. You are correct. Most lube huts are flat rate and need to turn volume. Thats why its fast. 2-3 hours I'm greasing door latches, cleaning batteries. I probably jack every wheel up and check bearings 3 times a year.
Your greatly mistaken if you think that. They operate on volume and profit pennies like the mega fleets. Just alot of pennies when you have 500 stores 24 hrs a day staffed with low paid lube techs.
Whatever. You have my truck for 30 minutes but charge me for 3 hours is profit. Shop rates are about 125/hr now and these places are charging about 400 for an oil change now. You do the math.
I just started buying my own oil, and took it to a local car mechanic. He did the change with my parts for $100 with a full chassis grease. Did this after loves asked for $600 for a full synthetic oil change. My total cost was $400
use valves and hoses and buckets and a pump and you can do it anywhere, no drips (if you use the hose clamps!!), just need a hardware store to recycle the oil EZ drain valve EZ OIL DRAIN VALVE EZ drain hose attachment STRAIGHT HOSE END two five gallon buckets with a good lid lock/seal and pour spouts, hand pump, some clear hose and a couple hose clamps from home depot next time i'm gonna get a mini drill powered inline pump, got to work smart
You'll be pumping forever with that POS. I used to do it that way. Then I got the lid with a handle pump built in and was still PIA. Now, I have a wide mouth funnel I put at the oil fill neck between the block and air pimping and just slowly dump the oil in. Such much easier and faster.