When choosing a bottle jack for any purpose, you must factor in a few considerations in order to get the best jack for the job. When it comes to a bottle jack, size really is important; the jack must be able to fit under the object being lifted in order to work. Conversely, if you choose a bottle jack that is too small, it could be dangerous if it lifts the object at all. Most jacks of this type have the lifting capacity clearly marked on the jack, and it is important to match the size of the jack to your lifting needs. The position of the handle on the body of the jack is critical to the ease of positioning the jack and being able to work the handle.
All bottle jack designs are not equal. When searching for the best jack for a specific purpose, size and lifting capacity must be considered. If you purchase a jack that is physically too large to fit under the project, you have purchased a jack you cannot use. This is also true with the lifting capacity of the bottle jack. In order to get the best jack for the job, you must ascertain that the lifting capacity is at least as great as the weight it will be called on to lift.
For an all-purpose jack, you may wish to choose a small version to use as an emergency aid. You will need to factor in the lifting height that will be required of the jack. While most bottle jack designs incorporate an adjustable threaded section that allows the jack to be extended for maximum lift, these can often be fragile in an inexpensive jack. If you are attempting to save money on the purchase, buy a jack that does not require maximum height adjustment. This may be the difference in a successful lifting action and a broken bottle jack that allows the vehicle to drop, which could injure you or the vehicle.
You also may want to purchase a jack that can be stored in any position. Many jack manufacturers advise the jack not be stored on its side. Electing to ignore this suggestion could result in leaking hydraulic fluid from the jack, as well as an inoperative jack when it is needed. To get the best bottle jack for your needs, you may wish to choose a jack that has a rubber grip on the handle. Some versions of the bottle jack use a plain steel handle that can become very slippery in the rain. Oil and grease on your hands may also make it difficult to twist the plain steel handle in order to release the jack and lower your vehicle.