pearstar

And the steering wheel starts to vibrate... (significantly around 70 mph, and strangely sometimes the vibration goes off for a few seconds) Haven't checked anything yet but the tire pressure readings are good. Any ideas?

VIPNiSS

only thing I could think that happen was during those two weeks the tires acquired flat spots.. just drive them a bit more and get them to wear a bit and see what happens..

rijowysock

tires from heat/cooling got flat spots in em, drive more.. and heat em up good... my lotus flat spots in like 4 days in the summer heat in my garage and a good long drive cures everything.

mcbit

My GTS on Pirellis but it will go away with 30 mins if brisk motoring. If you know you're going to leave the car for any length of time it pays to over inflate the tyres.

Funny thing is my CTT on Michelins never flat spots.

vyper340

What tires are on it?

It's likely flat spots and will work it's way out as you heat the tires up and drive. Better tires when it's time will reduce/eliminate the issue.

I have tried a few for the CTT and have found that the Yokohama's Parada X-spec seems to do MUCH better than the Pirelli and other OEM tires. Make sure you get the heavy duty rated tires for the HEAVY Cayenne or your flatspot issues will be a problem.

pearstar

The vibration was gone after a long trip. Looks like it was flat spots indeed. Thanks guys!