There’s a brutal math problem playing out in Phoenix-area loan offices right now. A buyer walks in with solid income, decent savings, and a pre-approval number they’re excited about. Then the lender runs the debt-to-income ratio — and that $750-a-month truck payment turns a $450,000 approval into something much smaller. Sometimes a lot smaller.

How much smaller? According to recent mortgage industry analysis, the average new-car payment in the US — now hovering around $730–$750 per month — is reducing homebuying budgets by approximately $135,000. That’s not a rounding error. That’s the difference between buying in Chandler and buying in a neighborhood you settled for.

Why a Monthly Car Payment Has Such an Outsized Effect on Your Mortgage

The mechanic behind this is your debt-to-income ratio, or DTI. Most conventional lenders want your total monthly debt obligations — car loans, student loans, credit cards, and the new mortgage payment — to stay at or below 43% of your gross monthly income. FHA loans can stretch that slightly, but the principle holds.

Run the numbers on a $750/month car payment, and you’ll see the problem fast. If you’re earning $8,000 a month gross, you have roughly $3,440 in total debt capacity (at a 43% DTI ceiling). Pull $750 out for the car, and your remaining room for a mortgage payment drops to around $2,690 — assuming no other debt at all. At today’s interest rates around 6.75–7%, that $2,690 payment supports a loan of roughly $415,000. Without the car payment, the same buyer could qualify closer to $535,000–$550,000. The gap? Right around $120,000–$135,000, depending on the rate and the lender’s specific DTI threshold.

That’s exactly what the analysis is pointing to. And it lines up with what I’m seeing on the ground here in metro Phoenix.

What $135,000 Means in the Phoenix Market

That number isn’t abstract in Arizona. Here’s what $135,000 in buying power means in practice:

As of recent market data, the Phoenix metro median home price has been sitting in the $430,000–$460,000 range. Being pushed from $480,000 to $345,000 in buying power isn’t a minor inconvenience — it fundamentally changes which zip codes are accessible. And if you’re buying in a market where new home sales are already under pressure from rate shock and inflation, losing $135,000 in leverage puts the most desirable inventory out of reach entirely.

The Trade-In Calculus: Car vs. House

Here’s the conversation I find myself having with buyers more often lately: is your car working against you?

If you’re 6–18 months out from buying, this is worth running through honestly.

Option 1: Keep the car, accept the reduced budget. This works if you’re buying in a price range where the reduction still gets you what you need. In parts of Avondale or Peoria, there’s still livable inventory under $380,000. You’ll be competing harder in those brackets, but it’s doable.

Option 2: Pay off or trade down the car before applying. A $0 payment adds that $135,000 back. If you’re sitting on $15,000–$20,000 in cash or equity, paying off a car loan before the mortgage application changes the entire picture. Yes, it’s painful. But it’s often the highest-ROI financial move a pre-buyer can make.

Option 3: Delay the car upgrade entirely. I’ve had clients who were eyeing a new truck or SUV 3 months before they wanted to buy a house. I talked them off that ledge. Drive the paid-off Honda for one more year. Get into the house. Then refinance the car once you’re settled.

The math is unambiguous here. A new car purchase right before a home purchase is one of the most common — and most avoidable — ways buyers torpedo their own pre-approvals.

What Lenders Are Actually Seeing

Loan officers across the Valley are flagging this more aggressively than they were 2–3 years ago. When rates were in the 3% range, buyers had enormous capacity cushion. At 3.5%, even a $600/month car payment barely dented the buying power because the monthly mortgage cost per dollar borrowed was so low. Today, at 6.75–7%, every dollar of monthly debt capacity is more expensive to replace with loan principal.

That rate reality isn’t going away soon. [The Fed has held rates steady](/ fed-holds-rates-but-mortgage-rates-still-wont-budge/), and mortgage rates have stubbornly refused to follow any optimistic projections downward. If anything, buyers need to be more strategic about DTI management in this environment — not less.

One thing worth noting: some buyers try to work around DTI issues by leasing a vehicle before a purchase, assuming a lease shows up differently. It doesn’t. A lease payment counts dollar-for-dollar the same as a loan payment in most DTI calculations. That trick doesn’t work.

What to Do Before You Walk Into a Lender’s Office

If you’re planning to buy in the Phoenix metro in the next 12 months, here’s the pre-mortgage checklist I give clients:

  1. Pull your credit report and list every monthly debt obligation with its minimum payment
  2. Add up the total — then do the DTI math with your gross income at the 43% threshold
  3. Subtract what you have left from your target mortgage payment
  4. If the gap is significant, identify which debts to eliminate first (highest payment-to-balance ratio usually)
  5. Freeze any new auto, personal loan, or credit inquiries for at least 90 days before applying

The buyers who show up to their lender pre-approved and already optimized get the best terms, the highest limits, and they close faster. The ones who financed a new Chevy Silverado three months before applying are the ones calling me frustrated, wondering why they can only afford half the house they expected.

Your car has four wheels and depreciates the moment you drive it off the lot. Your house appreciates — or at least it’s supposed to. Treat them accordingly.