WASHINGTON, Oct 17 (Reuters) - U.S. President Donald Trump on Friday signed orders approving significant tariff relief for U.S. auto and engine production and setting new 25% tariffs on imported medium- and heavy-duty trucks and parts starting November 1.

Trump is also setting a 10% tariff on imported buses.

Trump's order makes automakers eligible for a credit equal to 3.75% of the suggested retail price for U.S. assembled vehicles through 2030 to offset imports tariffs on parts.

He is also extending the import adjustment offset credit for U.S. engine production and for U.S. medium- and heavy-duty truck production.