Coilovers vs Height-Adjustable Springs: Which Should You Buy?
Coilovers vs Height-Adjustable Springs: Which Should You Buy?
Coilovers vs height-adjustable springs is one of the most common questions we get, and the honest answer is: it depends on what your car came with and what you want it to do. Both get you a lower, better-controlled car with real ride height adjustment — but they go about it in fundamentally different ways. This guide lays out how full coilover systems like our TL-ONE and TL-PRO compare with our TL-HAS height-adjustable spring kits, so you can pick the right tool instead of the trendy one.
What Each One Actually Is
Full coilovers: TL-ONE and TL-PRO
A coilover system replaces your dampers and springs entirely. Thunder Lane coilovers are built around 46 mm electroplated, fully rebuildable monotube bodies, and each set ships with its own CVP + PVP dyno graphs. The TL-ONE is single-adjustable with 20 clicks of rebound; the TL-PRO is a true 3-way — independent rebound plus low-speed and high-speed compression — with remote reservoirs. Every kit is valved to your declared use: street, track, time attack, autocross, drift or rally.
Height-adjustable springs: TL-HAS
A TL-HAS kit takes the opposite approach: it keeps your factory dampers and replaces only the springs with height-adjustable hardware. That means your car's adaptive damping and driver-assist systems keep working exactly as the factory intended — no error lights, no lost comfort modes — while you gain real control over ride height. We currently build TL-HAS kits for the BMW G8X M2/M3/M4 and the Porsche 911 (991/992), both at $1,200.
Damping Adjustability vs Keeping Factory Adaptive Dampers
This is the real fork in the road. With coilovers, you take manual control of damping — one rebound knob on TL-ONE, three independent circuits on TL-PRO — and you give up whatever electronic damping your car had. For a dedicated performance build, that's a feature: you tune the damper to the spring, the tire and the track.
With TL-HAS, you deliberately keep the factory dampers. On modern cars with genuinely good adaptive damping — a G8X M3 or a 991/992-generation 911 — that electronics package is doing sophisticated work hundreds of times a second, and it still functions fully with a TL-HAS kit installed. If your car's adaptive dampers are one of its best features, throwing them away to gain a manual knob can be a step sideways, not forward.
Ride Height Control: Both Deliver
Here's the part people miss: you don't need coilovers just to set ride height. Both approaches give you genuine, adjustable height control — coilovers via their threaded bodies, TL-HAS via height-adjustable spring hardware on the factory dampers. Either way you can close the wheel gap, level the stance, and fine-tune corner to corner. The difference is everything else that comes along with the height adjustment.
The Cost Difference
There's no way around it: a full coilover system is the bigger investment. You're buying complete rebuildable damper assemblies, custom valving and dyno documentation, and the price reflects that. A TL-HAS kit is $1,200 — a fraction of a full system — because your car's factory dampers stay in service and keep doing the damping. If your dampers are healthy and good, TL-HAS is remarkable value; if they're worn out or you've outgrown them, that money is better put toward a coilover system that replaces them properly.
Who Should Pick Which?
Pick TL-HAS if…
- You daily drive a modern car with adaptive dampers you actually like, and want an OEM+ result.
- You want ride height control and a tighter stance without touching the factory electronics or driver aids.
- You want the smallest sensible investment: both current kits are $1,200.
Pick TL-ONE or TL-PRO coilovers if…
- You're building a dedicated track, time attack, autocross, drift or rally car and need damping you can tune yourself.
- Your factory dampers are tired, or you've reached the limit of what they can do.
- You want rebuildable hardware with dyno graphs that can be revalved as the build evolves.
Our honest steer: if you're on adaptive dampers and the car is primarily a road car, start with TL-HAS. If the car is a serious track tool, go straight to TL-ONE or TL-PRO.
Built to Order, Either Way
Whichever route you choose, nothing here comes off a warehouse shelf. Every Thunder Lane kit — coilover or TL-HAS — is hand-assembled in Poland, built to order with a 4–6 week lead time, covered by a 6-month warranty, and ships free to the US, Canada, Mexico and Central America. Coilover spring rates are finalized with you before production begins.
FAQ
Do TL-HAS kits disable my adaptive dampers or driver aids?
No. TL-HAS kits keep the factory dampers in place, so adaptive damping and driver-assist systems continue to work as designed.
Can I lower my car with both options?
Yes — both coilovers and TL-HAS kits give you genuine adjustable ride height. The difference is whether damping stays factory (TL-HAS) or becomes manually adjustable (coilovers).
Which is cheaper?
TL-HAS, clearly — both current kits are $1,200, while a full coilover system is a significantly larger investment because it replaces the complete damper and spring package.
What cars are TL-HAS kits available for?
Currently the BMW G8X M2/M3/M4 and the Porsche 911 (991/992), with both kits built to order.
Talk It Through With Us
Still on the fence? Tell us what you drive and how you drive it — we'll give you a straight answer, even if it's the cheaper one. Start with the TL-HAS collection for OEM+ builds, or the TL-ONE and TL-PRO collections for full coilover systems.
