To sense and nonsense of a hydraulic floor jack this class the following comments:
In fact, not at least one does not need such a thing, if you have a decent original vehicle-specific board jack, for the upcoming biannual changing wheels.
The board jack (this is true at least for me known types) is actually much safer than the hydraulic universal jack, and the effort required to board jack's also bearable, especially since the problems when changing a wheel yes lie elsewhere, namely, for example, when loosening the tight every now and then bolts ...
Accordingly, an original jack is usually much more expensive than a small hydraulic universal trolley jack.
What remains is probably just the fascination of hydraulic ...
The principal problem in the use of a small floor jack are as follows:
The base plate:
this just is not specifically designed for the vehicle, as is the case with the board jack, but here there is a "universal support plates".
Strictly speaking, it means that the part fits anywhere really!
There is no flat bearing surface and certainly no padding.
A car so raised without further aids, lies with the whole load on only a very tiny bearing surfaces, which always leads to damage to the vehicle, at least on the paint / coating.
To avoid trying anything Protective under set (wooden boards, rubber mats, cardboard, etc.).
However, since the receiving plate is not flat, but somehow arched, and then provided with noses, all the action is always shaky!
No comparison therefore with a vehicle-specific car jack, which is provided depending on the car type, eg with a receiving claw one hand ensures a sufficient and flat supporting surface, on the other hand prevents slipping.
By the way, now and then you will find deals on rubber pads for Jack, but these are relatively expensive and do not fit well on these small devices (the receiving plate in this device here is about 6.5cm in diameter!).
My tip: a board, in which one of four grooves incorporated (eg simply with the drill, or any professional), which correspond to the tabs on the recording disk. Thus, the boards is much safer then ever on your plate ...
Moreover Another principle related problem:
When Rangierwagenheber recording point moves when lifting outwards. To compensate for this, would continue under the car the jack during the raising operation.
This only works in ideal conditions, such as on slippery workshop floor.
In practice, this usually does not work properly, since, for example, the wheels of the jack are small and, especially under load, barely able to overcome any unevenness in the floor (for example, the joints of paving stones).
Then there is the effect that the car is pulled outward while lifting.
The first leads to tensions, then also the slipping and / or damage lead.
So ensure the smoothest possible surface, possibly something suitable inferior!
The major professional car jack, for private use but far too expensive, too big, too heavy, etc., the disadvantages mentioned have not: they have large, flat, rubber-padded support plates and relatively large and high-quality wheels.
Ideal would be a small trolley jack with vehicle-specific recording, unfortunately, there's something not to buy.
Conclusion:
Normally, it is wrong to think that one reason alone need a car jack, because the board jack standard 'no good. Herstellerabhängig and in rare cases, there may be also negative examples where it does not, the board jack is apparently actually useless ...
Who uses a car jack, should be particularly careful. The part you can destroy a lot!
Be sure to also read the owner's manual of the car exactly where a car jack is not to be recognized and where such!