One of the first things I did when I bought my used Chevrolet Express was replace the tires. I knew nearly all my nomadic driving would be on pavement, so I got highway tires. Really good ones. And they worked well enough for my limited off-pavement driving.

About two-and-a-half years, 55,000 miles, and one flat later (a flat that occurred on pavement) it was time for replacements. I got the same tires.

Three years, 70,000 miles, and three flats later (two of the flats occurring off-pavement) I replaced the tires again. This time I decided to go with all-terrain tires because they’re supposed to be more puncture resistant. And because I was spending more time traveling rough “roads” on public land. And because they look more butch. (I need all the butchitude I can get.)

Most people think, well, yeah, a full sized van is essentially a truck, so switching to all-terrain tires is a natural thing. But what about something like a minivan? They’re intended as family haulers and grocery getters, not wilderness adventure vehicles. You can’t get all-terrain tires for them. And if you could, they probably wouldn’t fit. Right? That’s what I thought, anyway.

But out of curiosity, I started poking around tire sites. TireRack.com (which is in no way paying for this mention) offers a lot of easy to find technical information. I started with their shop-by-vehicle tire picker and chose, oh, how about a 2017 Dodge Grand Caravan. Tire Rack told me the factory tire size is 225/65R17. When I viewed the choices, it offered to sort them by category. And one of the categories was all-terrain. Wow, really?

Okay, but would they fit within the wheel wells without rubbing anywhere? I selected the ever-popular BFGoodrich All-Terrain T/A KO2. Then I clicked on the specifications. The overall diameter was listed as 28.5 inches, and the section width (widest part of the tire) was 9.0 inches. Then I compared those numbers to some highway tires, like the Michelin Defender LTX M/S. Its specs were also 28.5 and 9.0. Bingo! The all-terrain tires would fit.

Cool. What about, let’s say, a 2005 Honda Odyssey and its 235/65R16 tires? Hmmm, no all-terrain options. But what about newer Odysseys that have larger 235/65R17 tires? Yup. What about minivans with 18-inch wheels? Yup. And 20-inch wheels? Nope.

It used to be that all-terrain tires were made just for Jeeps, trucks and full-sized SUVs. The LT designation in the size stands for Light Truck. But the boom in crossovers—the SUV’s smaller siblings—has created a demand for more all-terrain tire sizes. So, depending upon your wheel and tire size, you might be able to fit all-terrain tires on your minivan. But it means shopping by specs, not necessarily by brand or price.

ABOUT TIRE SIZES

The first number is the tread width in millimeters. (Tread width isn’t as wide as the section width.) The second number is the sidewall aspect ratio—a percentage of the tread width. The R means radial ply construction. The third number is the wheel (the metal part) diameter in inches. Changing one of those measurements while keeping the other two the same will change the diameter (and therefore circumference) of the tire, which will also affect your speedometer reading and fuel mileage because of a slightly different number of rotations per mile. It’s possible to keep the same diameter/circumference by juggling two or even three of the measurements. A little bigger here, a little smaller there and you’re ready to go.

THE PROS OF A/T TIRES

More rugged

Deeper tread

Higher load rating

Better off-pavement traction

Longer life

THE CONS OF A/T TIRES

Higher cost

Higher weight

Lower MPG

Might be noisier