XRAY - Model racing cars

What scenarios would I use each one??
And would you use them together??

And I know you don't change your oil on the PSS what about springs??
Would you run standard springs or progressive springs (or would that defeat the purpose)

ARS - for medium to high grip asphalt tracks with little or no bumps

PSS - for most asphalt tracks where you need a more aggressive feel and more overall grip. We tend to use either 2.7 springs all around or 2.5-2.8 springs being our 2nd option. We use a shock oil range between 550-600 usually

PSS will work there for sure.

ARS you can try, I think it will work because there are 180 corners and ARS is better for this style of tracks as it increases steering