Luxury Automobile Limitations In addition to the business use limitation, the amount of depreciation allowed for luxury auto- mobiles is limited. Passenger autos are defined as four-wheeled vehicles made primarily for use on public streets, roads, and highways with a gross vehicle weight of less than 6,000 pounds." Light trucks or do not have a separate limit as they have had in the past." The depreciation ex pense limits for luxury autos and light trucks placed in service in tax year 2018 follow: Auto Limit Year 1 (2016) $18,000 Year 2 (2017) 16,000 Year 3 (2018) 9,600 Year 4 (2019) and succeeding 5,760