Chris from Ohio has a problem most people would envy: a bonus large enough to wipe out either his mortgage or his car loan entirely. His instinct shifted from the car to the house, and he asked Clark Howard whether he was missing anything. Howard’s answer was direct, and the math backs it up.
What Clark Howard Said
“Pay off the mortgage. Be mortgage debt-free. Car loans extinguish so quickly. Relatively speaking, 4% rate, that’s a low priority, even though technically the mortgage interest is deductible, the auto loan in some cases is, usually not. Blow out the mortgage, own your home free and clear, and then pay off the loan as you agreed.” Howard also flagged one thing Chris left out: “The big thing you didn’t say is how you’re saving for retirement. My obsession with people as young as they can to really devote energy and a percent of your paycheck to saving in an employer-provided Roth 401(k) or your own Roth IRA is a really, really ultra-high priority for you after you pay off the mortgage, before you would blow out the 4% rate on your vehicle loan.”
Howard is right. The advice is sound, and the interest rate math is the reason why.
The Rate Gap Is the Whole Story
Chris has $50,000 remaining on his mortgage at 6.125% and $45,000 on a car loan at 4.125%. That two-point spread makes the choice straightforward. The mortgage is simply the more expensive debt, and eliminating it first produces the largest guaranteed savings. Every dollar applied to the higher-rate balance saves more than a dollar applied to the lower-rate one, which is the entire logic behind rate-ordered debt payoff.
The word “guaranteed” matters here. Paying off a debt is a risk-free return equal to its interest rate. No investment can promise you 6.125% with zero downside. The 10-year Treasury yield currently sits at 4.21%, meaning even the safest investable asset in the world pays less than Chris’s mortgage costs him. Paying off the mortgage clears a higher hurdle than any bond he could buy today.
The car loan at 4.125% is a different story. That rate is only slightly above the current Treasury yield and well below the Fed Funds rate of 3.75%. The interest cost on the car loan, carried to term, is not trivial, but it is manageable and it is the lower-cost obligation.
The Deductibility Argument Doesn’t Change the Math Much
Some people push back on the “pay the mortgage first” logic by pointing to the mortgage interest deduction. The argument goes: if you can deduct mortgage interest, the effective rate is lower than the stated rate. Howard dismissed this quickly, and for most middle-class borrowers, he is right to do so.
The 2017 tax law roughly doubled the standard deduction, which means the majority of taxpayers no longer itemize. If Chris takes the standard deduction, he receives no tax benefit from his mortgage interest at all, and the 6.125% rate is his true cost. Even if he does itemize, the after-tax effective rate is still higher than his car loan rate for most middle-class taxpayers, so the hierarchy holds either way.
Who This Advice Fits
Howard’s recommendation works best for someone in Chris’s specific position: mid-30s, a remaining mortgage balance small enough to eliminate in one payment, and a car loan at a materially lower rate. When the rate gap between two debts is two full percentage points, the calculus is straightforward. Pay the expensive debt first.
The advice becomes less clear-cut in two scenarios. First, if both debts carried similar rates (say, 5.5% mortgage and 5% car loan), the psychological benefit of eliminating the car payment might reasonably tip the decision. Second, if Chris had no emergency fund, wiping out $50,000 in cash to own his home outright could leave him exposed if his car needed a major repair or he faced a job disruption. Before executing either payoff, three to six months of living expenses should already be sitting in a liquid account.
The Retirement Piece Howard Added
Howard’s addition about retirement savings is the most important part of his answer, and it deserves more attention than it typically gets in debt payoff discussions. A person in their mid-30s who becomes mortgage-free has freed up a meaningful monthly cash flow. If that cash flow goes toward a Roth 401(k) or Roth IRA instead of accelerating the car payoff, the compounding math over 25 to 30 years is likely to produce more wealth than eliminating a 4% loan two years early.
Roth accounts are funded with after-tax dollars, but growth and qualified withdrawals are tax-free. For someone in their mid-30s, that tax-free compounding window stretches across decades. The car loan costs 4.125% per year in interest. Many investors have historically sought returns above that level over long periods, though past performance does not guarantee future results. Carrying a 4.125% car loan while maximizing tax-advantaged contributions is a reasonable trade-off at that rate level, which is exactly what Howard is describing.
What Chris Should Do Next
The sequence Howard laid out is the right one: pay off the mortgage with the bonus, then direct freed-up monthly cash flow toward retirement savings before accelerating the car payoff. Concretely, that means confirming whether Chris’s employer offers a Roth 401(k) option, and if so, increasing his contribution rate as soon as the mortgage is gone. Chris should check the current IRS contribution limits for 401(k) accounts, which the IRS updates annually, and aim to contribute as much as his budget allows after the mortgage is paid off. Chris should also verify his mortgage payoff amount with his lender, since the balance may differ slightly from his estimate once prepayment interest is included.
Paying off a 6.125% mortgage with cash is a guaranteed return that no bond or savings account can match today. Carrying a 4.125% car loan while building tax-free retirement wealth is a reasonable trade. That ordering is the core of Howard’s advice, and the numbers support it.
Top Gaining Stocks
Top Losing Stocks