I put some new delta grand prix tour rs tires(TBC brand) on my 17inch(215/50/17) oem rims on my 2006 hhr right after I removed my 16 inch winter tires(205/55/16) and this winter we hit a big chunk of wood on the road with the left hand side of the car and I just replaced the left front steering knuckle both front struts (full assemblies) also new front stabilizer links and new rear shocks, new outer tie rods and got an alignment . As soon as I put the new summer tires I noticed the car seem to wander on the road but only sometimes like it would go in one direction all of a sudden, almost like being hit by a gust of wind but on a non windy day. I notice the left front lca bushing is worn out so I was going to replace the lca but with all of the old parts and the winter tires it didn't wander like it did with those new tires. So I was sure the tires are at fault, I guess my fault for cheaping out on tires but I run those same tires on a 05 mazda 3 and a 2013 civic and I don't have the same issues. Maybe the hhr electric power steering is more sensitive to the type of tires? But my winters tires are sailun brand which is also a Chinese tire but a better brand I guess. How can I be sure the tires are at fault before buying a new better branded set of tires?
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If that means anything, here is a pic of the summer tire tread:



Here is a pic of the winter tire tread:

 

Did you check the air pressure with a gauge, the correct pressure is on the sticker on the driver door frame.

 

I got 32psi all around.

 

Then I'll bet you need some front end work. Or the alignment guy screwed up, it has happened to me. bad LCA bushings can do that, and if it was aligned with bad bushings good luck ever getting it right.
That tread looks identical to the stock Firestones.

 

X2 the rear LCA’s bushings are shot!

 

x2 Hardly tires to blame

 

How do you check the rear lca bushings? Or are you talking about front lca's but the rear bushings on the lca?

 

I also thought it wasn't tires but the fact that the car didn't do this same behavior with 16 inch winter tires had me puzzled.

 

Sorry, dislexia, the front LCA’s rear bushings, you can remove the arms and press out the old bushings and press in new bushings or simply replace the arms, this also gives you new ball joints,
here’s a how to
https://www.chevyhhr.net/forums/www....ad.php?t=44378

and here’s how to check them

 

New tires can cause a drag ( soft rubber vs hard rubber ) soft rubber had more traction and wear faster ( lower mileage ratings like 25000 miles vs hard rubber at 50+ 000 mile ratings )
Threadwear and patterns play a huge role in traction. Broken belts or slipped belts in new tires can happen as did with my wifes avenger 18" tires... took forever to figure out what was causing the pull and it was a slipped belt, didn't find til the tire started wearing real bad in 1 spout.