Flat tire fix is spare on logic

Dear Car Talk:

As I'm sure you are well aware, more and more cars today are sold without a spare tire. In many cases, buying a spare and throwing it in the trunk – even a mini "donut" spare – would take up a lot of room. And in the event of a high-speed accident, that could be dangerous in a car in which the cargo area is open to the passenger compartment, such as a wagon, hatchback or minivan, if the spare becomes an airborne projectile. Owners are told to make do with tire-repair kits, which include tire-repair fluid and compressors to refill the tire with air. That's fine for most punctures, but not all. Here's my idea – my question is whether this would be safe: Buy a mini donut spare tire, but only the tire, not the wheel. Choose a size that is big enough to fit around a flat tire (with the wheel jacked up), but small enough that after filling it with air from the repair kit compressor, it will fit tightly around the flattened tire. With the flat still mounted, fit the deflated donut tire around the flat. Then inflate the donut tire, which will tighten it around the flat. Then drive, slowly. What do you think? Sounds crazy, but it seems to me it would work and be safe. I think the main issue would be making sure to turn at a low speed if the flat is a front tire, so that the tire is not pushed off of the wheel. – Greg

RAY: Greg, it's thinking like this that has kept you out of some of the nation's top universities.

The biggest problem with your idea is that tires are not soft. So it’d be almost impossible to “stretch” a tire over an existing tire. Sliding one tire over another is not like putting on two shirts. Tires have some flex in them, but they’re not very malleable.

If you’ve ever had a flat tire and jacked up your car, you’ve probably noticed that without the weight of the car on it, the flat tire resumes its normal shape. It’s not soft.

The other problem is that your existing flat tire will still be mounted to the wheel – which means the inner bead of the tire will be pressed firmly up against the inside of the wheel rim. That’ll make it impossible for you to seal that second tire over the first and get it to hold pressure.

So I think this is one of those great ideas that you probably shouldn’t mention to anyone else. Not for fear that they’ll steal it, but for fear that they’ll call the guys with the white coats.

Actually, there are lots of good ideas that are not workable at first, often for technological reasons. So this is my answer for now, Greg. But check back with me in 2030 when you can print a replacement zip-up tire from your spare 3D printer in the trunk.

Whack-a-fan fix won’t last long

Dear Car Talk:

I have a 2007 Toyota 4Runner. Two or three years ago, the blower went out. I called my service advisor at the Toyota place and asked what I should check before I brought it in. He said, "Reach under the dash on the passenger side and give the blower motor cover a hard whack." I did, and it started right up. This happened a couple more times, so I took to carrying a persimmon shillelagh in the car to whack the thing with whenever it failed to work. It worked like a charm every time. Eventually, the problem disappeared. No problem for two or three years – until today, when I got back into the vehicle at the grocery store. It was 104 outside, and the AC wouldn't blow. So I whack the sucker with my hand and, bingo, it comes on! So what gives? Do I continue whacking it until it no longer responds? Or do I go ahead and get a new blower motor now? I still have the persimmon shillelagh. – Dale

RAY: Well, you can keep whacking it if you want to. The reason that works is that when an electric motor fails, it's often because there's a bad connection, or the brushes are worn out and not making good contact. And giving it a physical jolt often can get it moving again, and then momentum takes over.

But eventually, whacking it will stop working. And you know as well as I do that it’ll be 114 degrees out the day that happens.

So my advice would be to just go ahead and replace it. You know it’s going to fail permanently at some point – why not replace it now and never have to worry about it again?

Or, if you’re really curious about how long you can go on like this, at least buy the motor and keep it in the car, along with a set of socket wrenches. You probably can get a new blower motor for less than 100 bucks. And then, when that day comes and the shillelagh doesn’t work, you’ll be ready.

The blower is just held in place by three screws. You’ll have to pull it out, unplug it and swap out the fan itself, which is attached to the shaft of the blower motor. Then you replace the screws, plug it back in, and you’re good to go.

Of course, you’ll be doing this under the dashboard, with your head upside down in 114-degree weather, Dale. So, like I said, I’d just do it now.

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