write off the interest? If I put a swimming pool or new A/C unit in my house that is depreciating asset also. I borrowed $25K from home equity line to purchase my truck out right in cash. The interest rate is comparable to a car loan. My insurance is cheaper being that I dont' have a lien holder also. I need all the deductions I can get in my income bracket. I also get to write off my sales tax on a new vehicle. That was another motivating factor.