What a difference a tire can make!
 

I don't know why I put this in the fuel economy section but ...
I've been dealing with funky noise and vibration for a while now. I've suspected a wheel bearing or worse, some kind of final drive problem. It's been getting slowly worse and lately I noticed a side to side shimmy at low speeds. That's when I changed my suspicion to a tire. I have noticed while pushing my car out of the garage a rubber squeeking sound from a front tire. So yesterday I decided to put my full size spare in place of the ds front tire. Drove to work this morning, I should say I floated to work this morning :D smooth and silently (except for normal econocar noises). I can hear my cruddy tinny radio so much better and can even look out my rearview mirror without having to stabilize it from vibration.
The tire I removed appears to have some belt problems and has a wierd feathering pattern on the inner shoulder. I probably have an alignment issue :( Could just be from the broken belts or something. It was pretty worn and didn't match any of the other tires anyway.

My tire was warped really bad. Ever look at the funny shape a tire gets when its parked half on the curb and half off. Well imagine it being permanently in that shape with some welts. Car would shimmy from side to side while driving and would get worse while driving slowly. Thought my rack/pinion was shot. Until I pardked on day with the wheels turned and actually saw the tire. The other tires were really worn (should have ALL been changed months ago), so I replaced and changed the remaining 3 the following month. WHAT A DIFFERENCE.

Yeah, seems like FE should go up after changing that tire too. Less energy robbing vibration and noise.

Once upon a time back in the bias ply days, tire shops "trued" tires inexpensively. The tires were put on a spinning armature and all the high spots were shaved off the tread while the tire was new. Tires so modified required little balance weight and had longer carcass life. This seems to have fallen out of favor because of supposed quality control in modern radials, but any tire that starts its life even slightly "unround" only becomes "unrounder" with use.

Call me old and superstitious, but I still do it. And now that I'm getting into the mileage game and running smaller tires at greater rolling rpm's and higher pressures I expect the benefit will be even greater.

Some tire shops still have the equipment to true tires and don't even know it. I had to show the young personel at my local shop what that funny-looking attachment for their spin balancer was. No one had used it in 20 years.

Of course there are other factors that could have caused your problem, such as a basic manufacturing defect in the carcass, or even switching tires to the other side of the car during a tire rotation.

If the tire you took off was oddly feathered, it's time for a wheel alignment.

Metros require constant rotation and will still cup tires no matter how often you get them alligned. Does it either with high quality tires or craptacular bargain tires.

Our Metro went through from 1993-2006 and in 98K miles:

Goodyear Invictas (on the car when we bought it new, wore fast)

Uniroyal Tigerpaw (GARBAGE, lasted maybe 5K miles)

Firestone F560s (wore like iron, cupped and made terrible noise)

Yokohoma Y372 (nice, least amount of cupping but 25K miles and shot)

Kumho 758 (OK, sold them with the car, wearing out FAST)

The plus is none of the tires here cost any real money. The tires for the front of my John Deere cost more than any Metro tire!

broken belts inside tire?
 

I'm right there with you. I began to think that a steering rack clip went bad on my CRX....or a wheel bearing was going. NOPE. I put the car up on jackstands then started her up & put it in gear. As soon as I walked around the car I could see that the front passenger tire had a HUGE tumor. I was pleasantly relieved. I suppose this little 32psi tire couldn't handle the constant 45+psi I was feeding it. Although, I really blame Virginia for their horrible I-64 road with those damn SPEEDBUMPS that they put between the cracked sections of the concrete every 50 feet or so. Yeah, uh, those don't bode well at 65mph for a tire that's already under stress.

GET RID of the speedbumps on major highways!

To the left of your posts it says "Junior Member". Maybe we should call you "Senior Wise One" or something.

how long does it take to become a sr member anyways one day i looked over and it was there i dont know how many post it was

It says "Junior member" cuz that's what I am, a novice. Most of you have been at this a long time and I'm just learning. But if something I happen to know from back in the day might be of value to you guys I'll toss it out there.