Guide for Selecting and Buying the Right Struts for Your Vehicle

Author: superspares  

Struts serve multiple purposes, including improving a vehicle's handling while turning or braking. At the same time, struts play an important part in the overall comfort level of both driver and passengers. Unlike a shock, which cushions the vehicle from bouncing up and down too much, a strut also provides side-to-side stability.

A strut's stability results from a combination of factors, including the spring rate of the strut, the weight transfer, and its ability to dampen any shocks experienced. Spring rate is the rate at which the strut spring responds to the force exerted on it, a factor largely determined by the amount of weight the vehicle carries. Weight transfer is the ability of a strut to transfer weight during stops, acceleration, and turns. Too soft of a strut and the vehicle dips, lifts, or canters deeply when sufficient force is applied. Too hard of a strut and there will be no reaction at all, having an effect on overall vehicle control.

The ability of a strut to dampen the forces involved in the movement of a vehicle from point A to point B is also important. Dampening is the ability of a strut to settle a vehicle back to a normal state after reacting to a shock, whether from acceleration, braking, turning, or driving across a rough patch of road.

When searching for struts, buyers should check into available product options before making a purchase. They should also learn about the different types of struts, where they are installed on a vehicle, standard strut sizes, and product terminology. They should also decide where to buy struts, such as at local auto part stores or online marketplaces like Superspares.

Discover Struts

When replacing struts, shoppers need to keep in mind the exact strut they need based on specific criteria, and they should know the different types of struts and the sizes available.

Strut Terms

To truly understand how a strut works, shoppers need to understand some of the terms associated with struts. The table below lists some important strut terms.




The stroke is a measure of the strut that fits into the spring leg

Extended Length

The total length of the strut, including the spring leg and the shock absorber

Shock Absorber

The shock absorber fits into the spring leg and helps dampen the shock from the road


In a coilover strut, the coil is the spring that fits over the shock absorber and helps further reduce shock

Spring Leg

Contains the cushions and springs that make up the main body of the shock absorber

Even though most struts function along similar principles, they attain their goal through different means. The above terms give shoppers insight into struts to help them choose the right strut for their needs.

Types of Struts

The three main types of struts are coilover, gas, and pneumatic. All three operate on the same principle of reducing the shock of over-the-road travel by dampening the shock produced through springs, oil, and gas. The table below details all three types of struts.

Strut Type


Coilover Strut

Coilover, or MacPherson struts, are shock absorbers with a spring encircling the top of the strut for increased dampening

Gas Charged Strut

Also known as a gas strut, these struts are fitted with oil like a pneumatic strut, but also have gas in the strut; the gas improves the performance of the strut by reducing foaming

Pneumatic Strut

Contains oil that creates pressure within the strut, dampening the the shock from driving; also called a hydraulic strut

Always service or replace gas-charged struts in pairs to prevent twisting caused by uneven loading. When replacing struts, it is also imperative that the same type of struts be used to replace worn or damaged ones.

Strut Placement on Vehicle

In addition to the different types of struts, there are also struts for different parts of the suspension system. This includes the front and rear, as well as the left and right side of the vehicle's suspension as listed in the table below.

Strut Locations


Front Strut

Helps dampen the shock produced from braking, especially the forces produced from sudden stops

Rear Strut

Keeps the back end of the car from bottoming out from a high rate of acceleration

Left-Side Strut

Helps dampen the shock produced when turning left; also keeps the vehicle from rolling too much in a turn

Right-Side Strut

Helps with vehicle roll in a turn; dampens the shock produced from right turns

When replacing struts, pinpoint the correct strut, or struts, to replace. Damaged, leaking, or worn struts should be replaced as soon as possible. This helps prevent strut failure and keeps vital vehicle components, such as tires, wheels, and the suspension, from being damaged.

Standard Strut Sizes

Remove the current strut to determine the correct strut size needed. Shoppers should note if the strut is a brand name or a standard strut. They should also copy down any numbering or lettering printed on them. Shoppers can also measure the strut from the top shaft to the bottom of the strut mount with a tape measure. They should then extend the shock all the way by pulling on the tube body and measure this length from the top shaft to the strut mounting bracket.

Shoppers can then either take their measurements, any lettering or numbering on the strut, and even the struts themselves to an auto part store to identify replacements, or use just the measurements, lettering, and numbering if shopping online. This information will allow shoppers to determine the correct strut for their vehicle if they want to buy struts online. The following sections contain common sizes for coilover, gas, and pneumatic struts.

Coilover Struts

The following table contains both the stroke and extended lengths of some coilover struts.

Stroke Length

Extended Length

60 millimeters

195 millimeters

160 millimeters

405 millimeters

210 millimeters

500 millimeters

260 millimeters

605 millimeters

300 millimeters

700 millimeters

360 millimeters

795 millimeters

When shopping for coilover struts, shoppers should be sure to get the correct size of strut for their vehicle.

Gas/Pneumatic Struts

The following chart contains the diameter of both the shaft and tube of gas and pneumatic struts.

Shaft Size

Tube Size

6 millimeters

15 millimeters

8 millimeters

18 millimeters

10 millimeters

21 millimeters

14 millimeters

28 millimeters

When replacing struts, vehicle owners need to make sure to purchase the right size struts. The wrong size strut can cause a failure with the suspension and damage the vehicle and the strut.


Making sure struts are in good working order keeps a vehicle in safe operating condition. Damaged or leaking struts can fail when a driver least expects it. They can also make the ride in the vehicle less than desirable, and can even damage components such as tires, wheels, and the vehicle suspension.

When replacing struts, shoppers should make sure to measure them for size, preferably in millimeters. This includes both the strut stroke length and the extended strut length. They should also note any numbering or lettering printed on the strut. This will help shoppers pick the correct sized struts for their vehicle. When picking a strut, shoppers should make sure to choose strut types that match their current struts, unless they are replacing all of the struts. If they unsure about what struts are right for their vehicle, shoppers can consult an auto parts store salesperson or mechanic.

But before buying struts, remember to investigate the available options and learn about the different types of struts, where they are installed on the vehicle, product terminology, and how to buy struts safely and securely.