I have a 92 buick regal with 50km and when I go around a corner the tires squeal...what can this be

Check the air pressure.

a 92 buick with 50 km on the clock squeals with delight at being taken for a drive

I'm with edgarblythe - sounds like air pressure problems!

Are you pretty sure it comes from the tires? I tend to associate screeching on corners, especially at low speed with power steering issues. Checking the fluid level is easy, as is poking the belt as a quick test of tension. The belts can also slip if they have become worn and develope a shiny gloss on the contact surface.

Of course, checking tire pressure is no big feat, either.