Limiter on my '08 HHR SS was 132. I don't know about other years.

 

Never heard of a limiter. GM at one point claimed a 152 or 153 top speed on the SS 5 speed less the Turbo Upgrade. That sounds logical under the right conditons due to the aero limitations of a tall boxy styling.

Some here have tried to duplicate it but it is difficult as GM I am sure did it under test track conditions that were just right. I figure the upgrade would help but at those speeds it takes more and more HP for every 1 MPH.

The GS would have an aero advantage and 6 speed tranny advantage but it pays a weight penalty.

Many private owned SS may have lower limits due to condition and state of tune. Lets face it not all are in the same condition at 50,000 miles as others are at 5,000 miles. One leaking intake or poorly functioning sensor can cost you a lot of HP.

 

Nitto NT 555 or Nitto NT 850's i have the 850 on now and super quiet and very sticky im at about 17,000 miles on them and its almost time for new ones, im getting the 555's next