Does the mass of a rigidbody related to its size?

Hello everyone!
I am working on a car simulator game.
I imported a 3ds car model but it was too small relatively to the city(map) and I
scaled the car almost 100 times bigger.
Do I have to change the mass in the rigidbody component of the car?
also the drag?
or it has no relation to the size?

You could fix the model import scale so that you can use scale (1,1,1) - this makes things a lot easier: double-click the model in your Project view to open the model Import Settings in the Inspector and change whatever the Scale Factor is to a suitable value, then click the button Apply at the bottom of the page. From what you’ve said, I presume that the current Scale Factor is 0.01 - replace it to 1.0, for instance, what will make the model 100 times bigger.

EDITED: The actual problem is the object size, not its scale - its size should be roughly equivalent to a real object, considering 1 unit = 1 meter. To know what’s the size of the car in meters, create a cube and adjust its scale so that it’s the same size of the car - the cube scale will be the car size in meters. Typical car dimensions are about 1.7 m wide and 4.2 m long (as the old VW Beetle, for instance). If your car dimensions are way different from these, you will certainly have problems with physics.

The Scale Factor field can be used to fix the import scale, so that the object gets the correct size when placed in the scene without having to change its Transform/Scale in the Inspector.

Yes, if u use rigidbody.setDencity