Floor jacks and bottle jacks are the most popular types of jacks used for automotive work. Both rely on a hydraulic system to do its job. In this article, I will tell you all about them so you can learn more about these tools.
Basics: Floor Jack and Bottle Jack
What Is a Floor Jack?
Floor jacks are tools designed to lift vehicles for maintenance and duties like tire replacement. They use a hydraulic system to raise and lower the tray or saddle, the part that gets in contact with the vehicle to lift it. They are operated by a handle that is used to apply or release hydraulic pressure to the cylinder, raising or lowering the vehicle.
What Is a Bottle Jack?
Bottle jacks are portable hydraulic systems made to lift heavy objects for maintenance or repair. The load stands on the top of the piston called “saddle”. It’s operated by a handle to raise the piston and a release valve to lower it.
Image: A large truck lifted up with a bottle jack for maintenance work.
1. Design and Shape
- Floor Jack: They come in different sizes and shapes, but they all have a horizontal piston attached to a base with wheels (that’s why some people also call them trolley jacks). The tip of the piston pushes a bell crank which has a long arm connected to the tray or saddle. The arm uses horizontal force to lift the load vertically.
- Bottle Jack: They have a bottle shape, hence their name. These devices are basically hydraulic pistons laid vertically. It has a relatively small base, and the main cylinder is attached straight to the saddle.
2. Working Principle
Floor and bottle jacks work on the same principle. They use hydraulic fluid, which is incompressible, and use Pascal’s Law and leverage to multiply the force the user applies to the handle and easily lift heavy objects.
P = F/A
Pressure (P) equals force (F) divided by the area (A) on which it acts.
In other words, in a hydraulic system, the pressure applied to a piston produces an equal pressure increase on the other piston. Suppose the second piston has an area 5 times bigger than the first; then the force on the second piston would be 5 times greater; however, the pressure exerted on the second piston is the same as the one on the first and smaller piston.
Both jacks store hydraulic fluid in a reservoir. As you move the handle up and down, the fluid is pumped by the plunger piston and passes through a check valve to the ram cylinder. Pressurized fluid reaches the ram cylinder, which transfers it to the ramp piston, the component that lifts the load. Both systems have a release valve that, once open, releases the fluid pressure, making the ramp piston go down.
3. Lift Range and Capacity
The jack’s specifications determine the lift range and capacity. If a jack is rated to lift 2 tons, it wouldn’t be safe to try to lift heavier things.
Floor jacks have lower initial height when compared to bottle jacks which makes them easier to reach beneath vehicles with low ground clearance. But what is interesting is that, given the same weight ratings, bottle jacks are less bulky than floor jacks, and takes less storage space in your vehicle. Besides, because of their vertical disposition, they often get higher than the horizontal and bulky floor jacks.
There are different sizes of bottle and floor jacks, from small, portable units to heavy-duty jacks made to lift trucks, in the case of floor jacks, and heavy machinery and even house foundations, in the case of bottle jacks.
You can find domestic and semi-professional floor and bottle jacks that can lift 2 or 3 tons, and professional versions of both types which can lift from 4 to 20 tons. However, you won’t find floor jacks with a lifting capacity of over 20 tons, but you will find bottle jacks capable of lifting up to 50 tons.
4. Differences in Size and Weight
Bottle jacks are more effective than floor jacks, mostly because they have a bigger piston (remember Pascal’s Law), and they don’t have to carry the weight of the trolley, wheels, and all the structure floor jacks have. That’s why a bottle jack is considerably smaller than a floor jack with the same load capacity.
5. Stability and Safety
Floor jacks have a wider base and are more stable than bottle jacks on all surfaces. Besides, floor jacks have a bigger contact surface with the vehicle, which makes them more stable.
Professional floor jacks, also called service jacks, have two pistons and safety pins to prevent the vehicle from falling if something goes wrong with the jack or if someone accidentally tries to lower it while you are working underneath the vehicle.
Bottle jacks base has smaller surface area which could be an issue when you place then on uneven surface. Stability issues aside, both systems use the same hydraulics, and even though bottle jacks seem more robust, floor jacks’ hydraulic systems are equally safe given the same weight ratings.
6. Durability and Longevity
It depends on the manufacturer and price range of the tool, but in general, floor jacks have longer life expectancy than bottle jacks. This is mainly because floor jacks are well built, and bottle jacks use lighter, thus less durable materials, sacrificing longevity to save weight.
Bottle jacks are usually cheaper than floor jacks in all price ranges and specifications.
You can get a cheap 2-3 Ton bottle jack for $25 to $30 whereas the latter will cost you at least double the amount.
Most folks think of getting a power tool such as an impact wrench or impact driver to make the tire change process easier. In my opinion, a bottle jack is a much better investment since lifting your car or truck with the mechanical scissor jack is going to be the toughest part of the process.
8. Maintenance and Repair
All types of jacks need periodic maintenance.
The hydraulic mechanism of both jacks needs to have its oil changed. It’s also important to check the reservoir and cylinder for damage, cracks, and leaks that can make the system fail.
The type of hydraulic oil and changing intervals should be in the user’s manual; if it doesn’t, it’s important to regularly check the tool for oil leaks and change the oil about every two years. In some jacks, you can just top the oil when necessary.
Additionally, floor jacks have other moving parts like the wheels, the lifting arm, and others that need to be greased and shouldn’t be neglected.
Jacks are built tough; however, always use jack stands when you work underneath your car to prevent the vehicle from falling in case of failure or an accident.
Pros and Cons of Floor Jacks
- Practicality: Floor jacks are lower than bottle jacks, which makes them ideal for lifting vehicles with low ground clearance, including sports cars and lowered vehicles. There are special ultra-slim models made to fit underneath the lowest cars.
- Stability: Floor jacks have a broad and stable base which helps them to be steady even on uneven surfaces. This also contributes to safety since it’s pretty difficult for a vehicle to fall from a floor jack.
- Durability: Even when they have more moving parts than bottle jacks, they have extended service intervals. With proper care, they can last for ages. Besides, they are built from tougher materials than bottle jacks.
- Easy to move: When you are using it in your garage or shop, it’s easy to move them from one car to the other thanks to their wheels. Besides, you shouldn’t try this at home, but a good floor jack with a proper set of wheels can be handy when you need to move an engine or a transmission inside your shop, and you don’t have much help available.
- Quick operation: Thanks to their stability and long handles, you can lift a vehicle with just two or three up-and-down movements.
- Price: Floor jacks are more expensive than bottle jacks.
- Size: They are quite large, which makes them hard to maneuver, mostly when you need to reach hard-to-access areas underneath a vehicle. They also don’t leave much space to work underneath the vehicle in case you need to work near them. Not to mention that sometimes you can’t find enough room to maneuver the handle.
- Hard to carry: Floor jacks can be difficult to fit in small trunks.
- Limited Lift: Because of their design, sometimes they can’t lift vehicles as high as similarly rated bottle jacks.
Pros and Cons of Bottle Jacks
- Affordable: They are inexpensive and cheaper than floor jacks, and even the cheapest models are reliable and useful.
- Compact and light: Thanks to their design, they are light and easy to carry. They don’t use much space and can be hauled in tight trunks or inside spare wheel holes. They also are lighter, which makes them easy to transport.
- High Lift Capacity: They are taller, which helps them to lift vehicles even higher than floor jacks. This quality makes possible to lift off-road vehicles and light trucks, even with a medium-sized model.
- Unstable: Bottle jacks have a narrow body which makes them unsteady unless they are used on even and flat surface.
- High Clearance Height: As bottle jacks have their piston built vertically, they are taller than the lowest floor jacks, making them unsuitable for lifting vehicles with low floor clearance.
Best Use Cases for Each Type of Jack
Here are some specific use cases where a one type of jack is more suitable than the other.
Situations Where A Floor Jack is Ideal
- When you need to work fast and safely.
- To work with vehicles with low ground clearance.
- Whenever you have enough room to move the jack.
- Where the resting surface is uneven (e.g., off-road trails).
- When you want to move the vehicle, machines, or other heavy items.
- If you own a car repair shop.
Situations Where a Bottle Jack is Ideal
- If you don’t have much room to work. I.e., you have sufficient ground clearance but not enough space around to bring in a larger jack.
- When you are on a budget.
- For construction industry.
- If you drive an SUV or a medium truck.
- When you don’t have much room in your luggage bay.
- Roadside Emergencies: To replace a flat tire or to lift the vehicle for repair. (they are still more stable than scissor jacks that come with most vehicles)
From my experience, I think you should take with you the jack that you can carry depending on your vehicle. I prefer floor jacks, but I also understand that if you own a big SUV with 21″ rims, it would be ridiculous to carry a big 4-ton floor jack in your trunk, just in case you have a flat tire. It’s a matter of common sense and practicality. I recommend having both for professional or DIY use, mostly if you work on the floor and even if you have a car lift.
Bottle jacks are very useful for doing some repairs, like removing and reinstalling a transmission or a differential, for example. You can reach beneath those parts easily with a bottle jack and use more than one if needed. Having both jacks and different sizes of bottle jacks can make a mechanic’s life easier.
Back to Contents
- Basics: Floor Jack and Bottle Jack
- Pros and Cons of Floor Jacks
- Pros and Cons of Bottle Jacks
- Best Use Cases for Each Type of Jack