WHEELS 'N CUSTOMS TECHNICAL GUIDE: LOWERING SPRINGS COMPARISON & COMFORT

When you decide to lower your car with a set of high-quality lowering springs, you inevitably end up with the two leading German spring specialists: Eibach and H&R Spezialfedern. Both manufacturers have supplied absolute OEM and motorsport-quality parts for decades, including official German TÜV certification. Yet they follow a fundamentally different philosophy when it comes to stiffness, progressive spring rate and the number of millimetres lowered.

In our workshop in Nijkerk we hear the same questions every day: "Should I choose the comfortable Eibach Pro-Kit or the deeper Eibach Sportline?", "Are H&R springs really that much firmer than Eibach?", "How do I prevent my car appearing lower at the rear than the front (the infamous droopy rear)?" and "How many millimetres can I safely lower on my original factory dampers?" In this in-depth practical guide the chassis specialists at Wheels 'N Customs compare the three most popular spring sets in detail.

Although all three sets are designed to bring the body closer to the tarmac, they cater to a completely different type of driver:

Why does one lowering spring soak up a speed bump smoothly while another feels immediately firm? The secret lies in the winding of the high-grade silicon-chrome spring steel:

• Linear Springs (Motorsport): The distance between all coils is identical. The same extra force is required to compress the spring by each additional millimetre. This is fantastic on a mirror-smooth circuit, but on public roads it produces a bouncy and uncomfortable ride.
• Progressive Springs (Eibach & H&R road springs): The coils at the top are closely spaced (soft range), while the lower coils are much further apart (stiff range).
  • Small imperfections: On cobbles, manhole covers and gentle undulations only the soft, comfortable upper section compresses. The car feels like it has a factory suspension.
  • Sporty cornering & hard braking: As soon as the body compresses deeper, the soft coils come into contact with each other and the solid, stiff lower section takes over the load. The suspension stiffens immediately, strongly reducing body roll.
• The Subtle Difference Between Eibach and H&R: Eibach uses a longer, smoother comfort zone in the initial spring travel. H&R builds its progressivity up faster to a stiffer level, so an H&R spring feels 'tighter in the springs' from the first millimetre of travel.

A common frustration among drivers who fit an arbitrary lowering kit: technically the car is lowered by exactly 30 mm front and rear, but visually the car looks like it’s leaning backwards as if the boot is full of cement bags. In Germany this phenomenon is known as the Hängearsch.

Can lowering springs be combined trouble-free with your original factory shock absorbers? The answer depends directly on the number of millimetres lowered and the current mileage of your dampers:

When your car rolls off the ramp with new springs, it is often still a fraction higher than expected. Always keep the two golden rules below in mind:

• Spring Settling-In (Settling): New spring steel and the rubber spring seats need approximately 500 to 1,500 kilometres to definitively 'settle' under the full vehicle weight. During this period the car typically sinks another 3 to 6 millimetres. Therefore judge the final stance only after at least two weeks of intensive driving!
• Mandatory 3D Laser Alignment: Lowering causes the control arms to automatically pull the wheels into a more negative camber and the toe often shifts towards slight toe-out. Without a professional 3D alignment the inner edges of your tyres can be completely worn down to the steel cord within 5,000 km. Always have the wheel geometry professionally corrected after installation.