Here is the full list of all 43 Mafia: Definitive Edition achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Completed the game on Classic difficulty
Performed a wheelie for 3 seconds
Found all Pulp Magazines
Completed the Collection
Found all Mystery Foxes
Collected 30 vehicles in the Garage
Found all copies of Gangsters Monthly
Found all 'Gangsters of the United States' cigarette cards
Found all of the hidden cars
Resisted arrest by the Lost Heaven Police Department
Found a hidden car
Completed "The Death of Art"
Completed the game on Easy, Medium, or Hard difficulty
Completed "Moonlighting"
Completed "Just For Relaxation"
Completed "Election Campaign"
Completed "Crème de la Crème"
Completed "You Lucky ..."
Collected 15 vehicles in the Garage
Completed "Happy Birthday"
Completed "Bon Appétit"
Completed "Great Deal"
Completed "Visiting Rich People"
Lost the cops after accruing a five star police chase
Completed "Omerta"
Completed "A Trip to the Country"
Lockpicked 5 cars on the streets of Lost Heaven and environs
Found a Mystery Fox
Reached 50mph while driving the Bolt Ace
Completed "The Saint and the Sinner"
Completed "Better Get Used to It"
Paid a fine to the Lost Heaven Police Department
Completed "Sarah"
Took Paulie to a Place of Disrepute
Completed "Fair Play"
Won the race
Completed "Ordinary Routine"
Found a copy of Gangsters Monthly
Found a Pulp Magazine
Completed "Molotov Party"
Found a 'Gangsters of the United States' cigarette card
Completed "Running Man"
Completed "An Offer You Can't Refuse"