The paper deals with both unreferenced and fundamental issues referring to passive suspensions of road vehicles that still equip the one billion vehicles running on the globe.

The following topics are addressed.

– Are analytical methods useful for early stage design of suspension systems?

– Why suspensions are shaped as we know them? Is there a simpler architecture?

– Are indoor tests useful to refine the design of suspension systems?

The respective answers to such questions state what follows. Analytical methods are very useful for understanding the actual behaviour of suspension systems as quickly available hints on performance and parameter setting can be obtained. The suspension that we see implemented in road vehicles is the simplest possible (a theoretical proof will be given). Indoor tests are very useful even at early stage design of suspension systems and allow the validation of analytical formulae, at least for what concerns the trends related to the tuning of suspension parameters.