Another point that may or may not apply to you. There are transaction costs with a home equity loan--surveys, deed prep and closing costs. Don't know if you're trying to use one to buy a new car, but factor in the cost of paying (or financing) the cost of an updated survey as needed (depends on individual lenders and your exact situation), closing costs and compute the net difference in rates after factoring in the mortgage interest deduction. It may not be the lowest cost of funds. It wasn't when I looked into a Heloc or traditional first mortgage (as my home is paid for) last fall.

YMMV, however, as we (in Texas) don't get favorable home equity rates, compared to what you may find in other states.