If you’re buying or replacing a vehicle that you’ll use in your business, be aware that a heavy SUV may provide a more generous tax break this year than you’d get from a smaller vehicle. The reason has to do with how smaller business cars are depreciated for tax purposes. Depreciation rules Business cars are subject to more restrictive tax depreciation rules than those that apply to other depreciable assets. Under the so-called “luxury auto” rules, depreciation deductions are artificially “capped.” Those caps also extend to the alternative deduction that a taxpayer can claim if it elects to use Section 179 expensing for all or part of the cost of a business car. (It allows you to write-off an asset in the year it’s placed in service.) These...