(Moved from WIKI to here)
Lowering Springs
Lowering springs are a common modification done to many performance cars. Alternatives to lowering springs include cut springs and coilovers. Or you could just leave things stock. That's no fun.
This post doesn't include Coilovers, we may do a different post for that!
Advantages
Lower center of gravity
Less weight transfer during cornering
Reduced rollover risk.
Aerodynamic Improvements
Disadvantages
Bottoming out
Scraping/rubbing with larger tires
Dealer might blame axle leakage on Springs and not warranty axles.
Springs
Note: Some manufacturers do not specify Base 500 vs Abarth vs 500C vs Abarth Cabrio. Lowering distance may vary. Often different vendors quote different lowering values for the same spring. When possible I got lowering values from the manufacturer. I believe (but could be proven wrong) all of these springs are progressive. Manufacturers don't necessarily report spring rates, or they report an average or maximum rate rather than progressive rates. Caveat emptor.
List of Common Springs for US Models:
Manufacturer / Model Lowering & Spring Rate (If Published) Stock Not Low / Front 195 - Rear 220 lbs./inch Eibach Pro-Kit 0.7 Front / 1.2 Rear (Abarth) / 1.0 Front / 1.4 Rear (Base) Eibach Sportline 1.3 Front / 1.5 Rear (Abarth) / 1.0 Front / 1.4 Rear (Base) Front 150 - Rear 195 lbs./inch AST Suspension 1.2 Front / 1.2 Rear H&R PN 29054-4 / 1.2 Front, 1.2 Rear (Base 500 / 500C) H&R PN 29054-6 / 1.0 Front, 1.3 Rear (Abarth), 1.2 Rear (Abarth Cabrio) NeuF by NeuSpeed 1.2 Front, 2.0 Rear / Front 220 - Rear 225-250 lbs./inch Vogtland 1.0 Front, 1.4 Rear - Users report 0.75 inch. (MadFiat's Recommendation) Madness V1 "Approximate 1.4 inch" / 119.9 to 234.1 lbs front, 119.91 to 199.90 lbs rear (Older version) Madness Sport 0.7 (Abarth) - Rates - Front 119.9 to 234.1, Rear 119.9 to 199.9 (is this the same as V1? Unclear) Madness Sport Plus 1.4 Front, 1.8 Rear (Abarth) - Rates - Front 97 to 194.1, Rear 159.8 to 199.9 lbs. Megan Racing 1.0 Front, 1.7 Rear
Final Thoughts
Should you put lowering springs on your Fiat / Abarth?
If you value ride comfort, then absolutely not. While some other cars can be lowered without sacrificing significant amounts of ride comfort, that is absolutely not true of a Fiat 500. There isn't much suspension travel stock, and even mild lowering results in a bumpy ride. Driving around town it will be jarring - especially if you are a heavier driver or carry adult passengers.
For handling on smooth pavement such as autocross or track days, a mild drop can be beneficial. If you value appearance and style, then springs are a quick ticket to low-town as well.
Ultimately, however, you will see better handling improvements by focusing on other improvements such as a stiffer rear torsion bar, rear shocks, front chassis braces, front tunnel brace and tires. If all you want to do is level your ride on an Abarth, you can even consider cut springs on the back of the car -- if done correctly. On a Pop/Sport/500 T, you can swap to an Abarth suspension to get a bit of lowness without losing much ride quality.
Also it is recommended with any springs to upgrade your shocks as well. The more aggressive the drop you select, the more important a shock upgrade becomes.
