I want to use my car as a daily drive.I bought Wossner pistons,which when you install them gives you 8:1 CR.As you know stock CR is 8.5:1.So I am wondering,should I go for little higher CR than 8:1 in order to have a better driveability in lower RPM?What is the highest CR that this pistons are capable ?

Higher CR is better for off boost torque, but you won't be able to run as much boost(your engine will be more susceptable to knock on lower octane fuel). And for a forged engine, that doesn't really make sense.

I run standard CR of 8.5:1 and I run 2bar boost, so your pistons will be fine.

Recent back to back tests prove to be inconclusive at this level.
The usual rules don't apply to the 5 cylinder when you drive the car.

Any differences are marginal so most keep them stock.

When I went to forged 8:1 CR i definitely noticed some difference in off-boost driveability, so if i had to choose again i would go for standard 8.5:1 as i don't run ultra high boost levels. The choice depends on your driving style, how much time you spend off-boost and the boost level you plan to run.

The reason I asked this question is that I do not want to lose off boost driveability,car is every day driver.The pistons are made for 8:1 CR,and I think to make a little higher CR(8.5:1) to keep the standard low RPM performance.I will not go for 2 bar boost level for sure,more like 1.6-1.7 for max boost level and 1.2-1.3 for every day.