Height adjustable spring (H.A.S) kits are hugely popular suspension upgrades that allow you to adjust the ride height of your vehicle without the need for a full coilover setup. Think of H.A.S kits like a regular lowering spring that has a range of lowering rather than just a fixed ride height.
In recent years, height-adjustable spring kits have become extremely popular among car enthusiasts thanks to their blend of performance and practicality, combining the adjustability of a coilover system with the everyday convenience of traditional lowering springs. Most enthusiasts lower their vehicles to improve looks and handling but aren't after a Nurburgring lap record and don't want the harshness that coilovers often bring to daily driving.
What is a Height Adjustable Spring Kit?
A height-adjustable spring kit is a suspension upgrade that allows you to fine-tune your vehicle’s ride height by adjusting the position of the springs on the struts. Unlike fixed lowering springs, these kits include threaded spring perches or sleeves that let you raise or lower the car to your preferred height, improving aesthetics, stance, and sometimes handling—all while often retaining your factory dampers.
How Are Height Adjustable Spring Kits Different From Lowering Springs & Coilovers?
Height-adjustable spring kits differ from lowering springs and coilovers in how they control ride height and suspension performance. Lowering springs offer a fixed drop with no adjustability, while coilovers combine adjustable springs with matched dampers for full control over ride height and damping. In contrast, height-adjustable spring kits let you fine-tune the ride height like coilovers, but they’re designed to work with your car’s original dampers, offering flexibility and adjustability without replacing the entire suspension system.
How Do Height Adjustable Spring Kits Work?
Height-adjustable spring kits work by using threaded collars or adjustable perches that sit on the suspension strut, allowing the spring’s position to be raised or lowered. By turning these adjusters, you can fine-tune the ride height of your vehicle without changing the springs themselves.
The typical range we see on most height-adjustable spring kits is usually between 20mm to 50mm of adjustment, depending on the vehicle and kit design.
One of the best things about opting for a H.A.S kit over a lowering spring is that you can change your mind. If you're tired of scraping on speed bumps, you can simply increase the ride height back to a more practical level. They really are the best of both worlds.
Benefits of Height Adjustable Spring Kits
- Customisable ride height
- Improved stance and aesthetics
- Enhanced handling (with limitations)
- Retention of factory comfort (compared to full coilovers)
- Retention of factory electronic damper control functions (EDC)
- Ride height can be tweaked and changed for different applications
Things to Consider Before Buying
- Impact on ride quality and suspension wear
- Need for proper installation and alignment
- Legal considerations (e.g., UK MOT and ride height regulations
- More expensive than traditional lowering springs
- Not as adjustable as a full coilover kit
Can I Install Height Adjustable Springs At Home?
Yes, you can install height adjustable springs at home if you have the right tools, mechanical experience, and a safe working environment. The process involves removing your suspension struts, compressing the springs, and fitting the adjustable components—so a spring compressor, torque wrench, and jack stands are essential. However, if you're unsure or inexperienced, we'd recommend professional installation to ensure correct fitment, safety, and proper alignment.
Common Questions We Get About Height Adjustable Spring Kits:
Are they good for daily use?
Yes, height-adjustable spring kits are well-suited for daily driving. They let you customise your ride height while typically retaining factory ride comfort, making them a practical choice for both everyday use and weekend drives.
Will they void my warranty?
In most cases, fitting a height-adjustable spring kit won't void your entire vehicle warranty, but it could affect coverage related to suspension components. It's always best to check with your vehicle manufacturer or dealership before installation.
Will I need new dampers?
Not usually. Most height-adjustable spring kits are designed to work with your car’s original dampers. However, if your shocks are worn or old, upgrading them at the same time can improve performance and longevity.
How often should they be serviced?
Height adjustable springs themselves require minimal maintenance, but it’s a good idea to check them during routine servicing—especially for cleanliness and correct adjustment. If you live in a harsh climate, occasional cleaning of the threads can help prevent corrosion or seizing.
Which brands offer the best value?
AST ALS (Adjustable Lowering Springs) and KW H.A.S (Height Adjustable Spring) kits are two top-rated options. AST ALS kits are known for premium build quality and compatibility with a wide range of performance vehicles. KW H.A.S kits offer smooth height adjustability, excellent corrosion resistance, and are TUV-approved, making them a solid choice for both performance and daily comfort.
Final thoughts: Yes or No?
Height-adjustable spring kits offer the perfect balance between style, practicality, and performance. They allow you to fine-tune your vehicle’s ride height for improved stance and clearance, all while keeping the comfort and reliability of your original suspension setup. With easy adjustability, minimal maintenance, and compatibility with stock dampers, they’re a smart upgrade for drivers who want more control without going full coilover.
If you’re looking for a suspension solution that’s daily-driver friendly, customisable, and built to last, a high-quality adjustable spring kit—like those from AST or KW—is a great choice.
