Well it seems the Firestone Firehawks on the new HHR aren't fond of cold weather. I took Boo Boo out this afternoon and merrily bounced my way eight miles to the I-85 interchange and then another two miles or so on the highway. OK it did get down to 14 last night and it was up to maybe 20 in the garage, but cripes these buggers shake the heck out of you. Anybody else have "bouncy ball" Firestones or am I just insanely lucky?

 

Before I replaced my factory Firestones one of them had the morning flat spot, didn't even have to be particularly cold..... went away after about 5 miles. Made me remember the old days with bias ply/fiberglass belts.

 

But if I want to remember the old bias ply days I just take a Corvair, I didn't think "thumpity thumpity" made a comeback.

 

Yup - I've noticesd this problem as well. My car's garaged, but it's probably not much warmer in the garage that it is outside. Nights been geting down to 38 or so recently. Takes about 10+ miles for the vibration to go away in 48-50 degree temps in the AM.

Do you think that slightly increased tire pressures may help? Just bought the HHR a few weeks ago - haven't checked the tire pressures yet.

And yeah, I've got Firestones..

 

Not sure a pressure change would do much(unless you're way low or overinflated), it seems to be an issue with the rubber compounds in the tires. My dealer said he's had a few complaints about flat spotting with the Firestone's but more complaints about the Hankook's coming through on other models. I guess I'll adapt to them, only have 208 miles on the truck so far and we're dealing with record cold. So far this is the coldest December on record, temps are averaging about 30 degrees below normal. Thankfully the heated seats keep my teeth from chattering at the same frequency as the tires otherwise I might start losing body parts.