a vehicle has a 5years MACRS depreciable life. however, under the rules, it takes 6 years to fully depreciate it. if you take 179, if business use, for any reason, drops below 50% before the 6 years are up you have to recapture the 179 depreciation you took but you get the depreciation you would have been allowed if you had not used section 179.
179 is a rediculous tax provision because in most cases where section 179 is allowed section 168(k) - bonus deprecition is allowed up to the same amount as the would e 179. the difference is there is no business income limitation for 168(k) nor is there recapture as business use changes. however, even with 168(k) when you dispose of an asset you have to determine gain or loss based on the net businsss tax basis and any gain on the personal portion is taxble (same as with 179)
