There's a lot that can be stated on this topic. I guess this prospective really boils down to 'what your used to driving' and 'how you drive'. Granted, the HHR's OEM (16" or 17") wheel combo isn't (100%) the best for performance (could be lower profile and wider) NOR comfort (could be taller profile and skinny-er) -BUT- it does provide adaquate feedback and handling while at the same time providing a 'relatively' smooth ride.
One factor... if someone's used to driving a vehcile that has 100hp with 15" tiress (skinny), chances of noticing hydroplane (although they still exist) are noticably reduced. Compare this with, let say an extreme measure, a Vette (wide rear meats with big hp) and the difference is night and day. Then again- weather will play an important role...
Second factor... overall vehicle weight. The HHR is pretty light, which contributes to gas mileage, "feeling the power" (albiet ever so small), and handling. The downside is that being blown around at highway speeds and loss of traction in adverse weather.
Mix these factors together and stir gently.
Sure- there ARE better tires on the market (designed to do one thing better than another... water channels, sipped snow tires, soft rubber for grip, etc...) but OEM's typically 'try' to get the best of both worlds (handling AND wear)- which is almost always impossible! Guess this is just one driving 'characteristic' of this vehicle.
I personally think the vehicle handles GREAT, in ANY condition, but strive to drive according to the conditions (inherent from riding motorcyles over the years). Of course - I'm no 'expert'. I'm not saying anyone's a 'bad' driver, or that the HHR couldn't use better rubber... just that everyone's observations/perception on this will be different. These are just a couple 'considerations' that some people might overlook and interpret as a 'bad handling vehicle' without logically putting any thought into it.

BTW- I have 'hydoplaned' in the HHR on a couple occasions... but nothing more than what I used to do in my Probe GT- and nowhere near what I used to do in my Mustang GT.

 

That is a bad call; as tire manufacturers have no idea what vehicle their tire is being installed on. Vehicle weight, weight bias, vehicle load and handling dictate the proper tire pressure on any vehicle - not the tire itself.

Example: a 31x10.50-15 offroad tire will require 32psi for proper inflation on a full-sized pickup. That same tire would be extremely overinflated at that pressure on a Jeep, and running underinflated at that pressure on a large SUV (think Navigator here).

Proper tire pressure is a relative thing; relative to what vehicle the tire is installed on.

 

Boy there is a lot of thrashing going on here. So I will just add a little to it. Here is prime example, my '96 Chevy C1500, Ext Cab, 5.7 auto had a Leisure Conversion Package initially. The door label indicated a 15x8 wheel with a 275/60R15 tire at 44psi F/R. Original tires were Goodyears. I swapped with BFG's with a max pressure of 36psi. I'm definatly not going to run 44psi in a tire with a max psi of 36 (same load range BTW). Later in life, everything was switched to a 255/45R18 tire/wheel with a max psi of 51. So, what do you run? You contact the tire company and ask them what is a recommendation for this tire on said vehicle. They have experts on this. The Ford/Firestone problem was a lot more Ford than Firestone as Ford was told to run those tires at xx psi and Ford though it made the Exploder ride too rough. And they elected to run them at a lower psi. Tires got hot and blew. But, the door label is a good start. I would not recommend running a lower pressure withough some good research. Max pressure on a tire is just that, the max it "can" run. But low pressure in tires, especially one that frequent on the interstate, can be dangerous.

My

 

Hey! Did I remember to say I love my HHR? All I'm saying here is I like to be able to steer my car even if it is raining and I'm maaaybe driving a little too fast.......and I still think the tires SUCK
But I wouldn't trade my HHR for something else just because of it.

 

DITTO

 

We have two 2007 HHRs in my family. I drive an LT with the standard 16" allows and 33,000 miles on the original tires, my wife's is an LT fall special edition with 17" allows and 19,000 on the originals. Mine handles just fine in rainy conditions, but her's hydroplanes like crazy even at lower speeds, 40-45. Is it just the wider tires that are on the 17" wheels or something else?

 

IIRC, the 16" & 17" both have 215mm wide tires, no ?

 

My 2008 HHR doesn't do well in the wind or past about 75 mph. I should have my rear anti sway bar by the middle of the week. I'm hoping it will help. I love the little car but it is a challange to drive it on the highway.

 

I drove my HHR in a really bad rain storm for the first time. I had just changed the wiper blades, and one came loose! I got under an overpass and secured it. On the interstate, even down about 60 MPH, the car seemed entirely different from usual! It felt very tentative and insecure in its handling in a very vague and uncomfortable way. I later checked tire pressures and they were 30 all around, and am running new Firestone Serenity (?) tires on my 17 inch rims. I have now pumped them up to 35 as specified on the door jamb. I also am getting my TTR rear sway bar installed tomorrow, so I will see how it handles with sway bar in the next big rain storm. I just was surprised how insecure my HHR felt in heavy rain, as opposed to a dry road or light rain.

 

The low tires alone can give an un-easy feel..