If all has to do with vehicle weight, aerodynamics, and car design as to how well it grips the road. Perhaps a different brand would give more control, but who knows?
Maybe your tires are worn out.
Regardless, if your car is unstable at 70km/h, don't go that fast.
Maybe you are sensible and the other guys are reckless.
I drive a 2011 Volkswagen golf. And I change all the tyres to winter tyres when winter is about to come.
(I use Continental Conti Winter Contact 830P)
When I was driving on the highway last year (with about 1 inch of now), I can feel my car is starting to lose control when I go above 70km/h.
But I saw other cars, like honda civic, toyota corrola etc, they seem to have no problems going at 100km/h.
I have already had four winter tyres installed, and I did checked the tyre pressure every week...
Why my car is not able to go fast as others? Anything I was doing wrong?