Putting your car loan on your mortgage could cost you more than you think

And technically? They’re right. But here’s the part they don’t say loudly enough:

You could still be paying off that car long after it’s stopped being worth anything or after it’s left your driveway altogether. A car loan spread over 20 or 30 years inside a mortgage might feel manageable week-to-week, but over time it can become one of the most expensive ways to buy a vehicle.

And for some homeowners, it might not even be an option.

The problem with putting a car on your mortgage

Vehicles are depreciating assets – meaning they slowly become worth less over time. Homes (generally) do the opposite; they appreciate – meaning they’re worth more over time. That’s why combining the two can get messy.

Another way to think about this is while the car gets older, less valuable, or eventually replaced altogether, the debt can keep quietly hanging around in your home loan. It’s the financial equivalent of paying a streaming subscription for a show you stopped watching years ago.

The “lower repayments” trap

One of the biggest reasons people add vehicles to their mortgage is because the repayments look smaller and they often are.

Spread a $30,000 vehicle purchase across a 30-year mortgage term, and the weekly cost can look surprisingly affordable. But smaller repayments over a much longer period can mean significantly more interest paid overall.

A shorter-term vehicle loan is designed to end in the shorter timeframe. A mortgage isn’t.

That distinction matters a lot.

Your home becomes the security

This is the part many people gloss over far too quickly. When you put a vehicle purchase onto your mortgage, the security against that debt is your house.

Not the car. Your home.

With vehicle finance, the loan is usually secured against the vehicle itself. The debt is tied to the thing you’re actually buying.

At MTF Finance, that’s how we think it should be. Your home is likely your biggest investment. Using it to fund assets that lose value quickly can create unnecessary risk - especially if life changes unexpectedly.

Some people may not qualify anyway

Let’s take a step back and talk about loan-to-value ratios (LVRs) and how they come into play. In New Zealand, banks use LVR rules to assess how much equity you have in your home compared to how much you owe. The Reserve Bank restrictions mean lending above certain LVR thresholds can be limited or more difficult.

If you already have less than 20% equity, topping up your mortgage for a vehicle may not be straightforward.

Some banks may say no to additional lending entirely. Others may apply stricter affordability checks or higher costs for low-equity borrowers.

How about all of that in plain English? Even if your house has gone up in value, that doesn’t automatically mean the bank wants you borrowing more against it for a car.

Why dedicated vehicle finance can make more sense

There’s a reason vehicle finance exists as its own category. Cars aren’t houses, so they shouldn’t always be financed like houses.

A properly structured vehicle loan gives you a clearer finish line. You know what you’re repaying, over what timeframe, and when it’s done.

At MTF Finance, our loans are designed to work around real life and most importantly, to end.

That means:

• Faster approvals, often the same day as you apply
• Loan terms designed to end within a realistic ownership period
• Security against the vehicle itself, not your home
• Flexible structures and balloon payments to help manage cash flow
• Repayments tailored to suit your budget, not stretch it thin

Because sometimes the goal isn’t just getting approved. It’s making sure the loan still feels manageable six months, one year, or three years down the track.

At MTF Finance, our loans are designed to work around real life and most importantly, to end.

The hidden psychology of mortgage debt

Sometimes when debt disappears into your mortgage, it becomes less visible. Out of sight, out of mind is not best practice when it comes to your money.

Over time, homeowners can unintentionally turn their mortgage into a catch-all account for lifestyle spending, and while the repayments may stay “comfortable,” the overall debt can quietly grow in the background.

Short-term purchases that are often added to the mortgage and forgotten about include:

• A car
• A renovation
• A holiday
• Another car

A better question to ask

Instead of asking:

“How can I get the lowest weekly repayment?”

It’s worth asking:

“How long do I actually want to be paying for this car?”

For most people, the answer probably isn’t 20 or 30 years.