Frank RAY:

continued from E1 that you’re wasting fuel and creating more pollution than you would have if the car were off.

But the pull of an 80-degree car interior on an 8-degree morning often is powerful enough to outweigh the 30 cents’ worth of gas you waste, and the tenthousandth-inch sea rise you’re personally causing.

You’re still right, Richard, that the best way to warm up your car is to start it up, and if it starts, gently drive away. A car warms up faster when it’s driven, generates less wear and tear, wastes less fuel and pollutes less.

But no excessive mechanical harm is done to the car by warming it up in the driveway anymore.

Why are these new tires so leaky?

Dear Car Talk:

Since replacing the tires on my car 18 months ago, I’ve experienced several flats. The tires are Goodyear FuelMax.

When I bring the car back to the tire shop, they inspect the tire and find no puncture.

The only reason the mechanics at the shop and I can come up with is that the barcode labels positioned along the bead of the tire are causing the seal to break. Could there be any other reason?

–

There shouldn’t be any bar-code labels on the bead, Frank. The bead is supposed to be 100 percent dead clean when you mount the tire.

Otherwise, the tire won’t seat properly, and air will leak out.

So there’s nothing permanently embossed on or etched into the tire that interferes with the bead.

And if there’s a removable label of some kind that came with the tire, the installer should have removed it. If not, that’s a real rookie mistake, and that’s on him.

Assuming the bead was, in fact, clean when the tire was mounted, then you’d look for either a bad air valve or some problem with the rim that was preventing the tire from seating properly.

On an older car, that could be rust or corrosion. Or on a car of any age, it could be a bent, warped or cracked rim; I doubt the problem is with the tires themselves.

So if you’ve been back to the installer more than once with nonpunctured flat tires, have them remove and remount the tires.

If you have an older car, without a tire-pressure monitoring system (TPMS), you can ask them to replace the air valves, too.

Those older valves are a couple of bucks each. On newer cars, the tirepressure sensors are built into the air valves, making those too expensive to replace without evidence that they’re faulty.

But while the tires are off, they can check again and make sure there are no dents or corrosion along the beads that are causing your leaks. Or if they find a price tag there, they can discreetly remove it.