The ability to write off a big chunk of a heavy SUV's cost in the first couple of years can make purchasing such a vehicle more attractive than leasing it — that is, if the vehicle is used extensively for trade or business purposes. But be careful: in order to be eligible for these special tax breaks, you'll have to be able to show that at least 50% of the use of the SUV was for business. In addition, if your business use drops below 50% for some later years, you may have to "pay back" some of the $20,000 tax break you've already taken. Consult your tax advisor for further details, and to see whether purchasing an SUV would make sense for you.