How to get the smoothest possible ride (raising suspension?)
 

I bought my second HHR and I don't understand why it has such a smoother ride compared to the other one. I interchanged the tires to compare, they both use exact same tire, and still, one has much better comfort than the other. On the previous HHR, I have changed struts and bearings and although the ride was decent it never got close to the comfort of the new HHR. Could it be that control arm and/or tie rod can also affect comfort? These are the only parts I left untouched on my previous HHR. Also could it be that the suspension can be raised to improve comfort? It seems that the new HHR drives like an SUV. The other one drives more like a car. I don't understand and it bugs me.

They look very alike but the new HHR seems about one inch taller.... I think it's the suspension.

It could be the struts and shocks, different brand then your old HHR
they might be Monroe Quick struts , or the PO installed KYB struts and shocks and aftermarket springs.

What makes one ride smoother than another I would think the condition of the tires, wheels, suspension and steering parts.
What makes one taller than another wheel and tire size and coil, shock/ strut used
Unless of course you are comparing apples to not apples like SS to a LT

The Quick struts have new springs in them so that would account for the taller stance in the front and rear coils are known to break, and the aftermarket springs are also a little taller.
Tha and the old GHR’s lca bushings could be shot, the coils out back could be broken, struts leaking, ball joints are toast, depending on their age .

They are almost the same HHR. One is a 2.2L LS from 2007 the other one is a 2.4L LT from 2007.

I really like the feel of driving an SUV better than the feel of driving a car.

What SUV are you comparing to?

I recall driving the midsize SUV Toyota Venza (made in 2014 I think) and I was impressed by pretty much everything about it.

If there is a height difference of 1" then I would suspect the springs are not stock.

The 2.4 makes it an 2LT with FE3 suspension while the 2.2 LS has FE1.
Look at the RPO codes in the glovebox.
Different springs front and back.