Most jacks will hold the weight of the car on one side. Just jack it up to the minimum you need to get the tire off. Make sure the surface is solid..you will have no problem.
If you have it resting on a solid surface and crank it down so it doesn't sit too far off the ground, and no one is going to mess with it, you should be fine. I've left it overnight once. If it's close enough to the ground, worst case it slips off the jack a few inches, and as long as the jack falls clear, it won't do much to the wheel.
Mechanical jacks don't bleed off, so as long as it doesn't fall of the jack it will stay there as long as you want, Just make sure your on a flat even solid surface and you should be fine.
as long as its securely fixed on flat sound surface and no movements by passing vehicles that can wobble it or unbalance it then yes. ideally put few bricks or make some height with broken paving or anything else under a strong structure near suspension so it it did fall. it only an finch or three and onto a strong support point of car thus avoiding bodywork damage etc.
I'd get a big block under the axle, just in case. Plus, you NEVER work under a vehicle held-up with just a jack - ALWAYS have a second system.
Yes. Provided the car and jack are undisturbed it should hold forever.
YES
yes, it will be fine
So I blew my right back tire last night, but luckily I have an extra tire in my garage. The problem is tho, is that I have to remove my old tire and take it to the shop to get the new tire mounted on my rim, but I don't have any stands or any big enough objects to shove under the car to to hold it up until I come back with the new tire. Would my mechanical jack that came with the car be safe enough to hold the car up for an hour to 2 hours tops until I come back with my new mounted tire?
