On a Tesla Model Y, do snow chains go on the front or the rear wheels?

On the rear only. The Model Y owner’s manual says tyre chains should only be installed on the rear tyres, and carries a separate caution never to use snow chains on the front tyres. Tesla has tested and approved three König references depending on tyre size, and asks for wheel covers to be removed before fitting source.

Why only at the back

The manual lists one approved chain per size: König CG-9 size 105 for 18-inch tyres, König XG-12 Pro size 252 for 19 and 20-inch tyres on five and seven-seaters, and König K-Summit XXL K66 for 21-inch tyres. It warns that non-recommended chains, or chains on other tyre sizes, can damage the suspension, body, wheels or brake lines. Its other rules: never on summer tyres, avoid heavy loads that reduce the gap between tyre and body, check links and fittings before each use, never deflate the tyres to fit chains, stay under 48 km/h and take them off as soon as conditions allow.

If your Model Y has wheel covers, take them off first: the manual says fitting chains without doing so can cause damage the warranty does not cover. To find out whether the country you are driving in requires chains, winter tyres or neither, see the full article on winter tyre rules below.