Asked my DH who just retired after 40 years with wheel alignments. Our DS runs two tire shops. Best advice cannot be given thru a forum, but by taking it to an alignment shop to see which tires are wearing and the pattern of the wear, as that will be the answer to your problem.

The wear pattern on the front tires diagnoses the problem - whether it's overinflation, the more common underinflation, or alignment problems. My experience is to usually get 30-40K miles from tires on new cars and then 50-60K on better tires (usually Michelin) I use to replace.

My more recent car purchases have 10K mile oil change intervals and I've been using synthetic oil to good effect for the past 15 years or so. I don't have the tires rotated in-between.

Remember that your front tires get more wear and tear than the rear due to the sideways drag from turning.

Very true, Eliz A. That's the first main reason why rotating extends the life of a set, the second is that drive wheels sometimes have more wear, the third is that front/back weight distribution is rarely 50/50 and the tires carrying the heavier load get more wear. In the old days, rotation was done in a X pattern but I think it's more common now to just do front to back, keeping on the same side.

For those who don't buy new tires a set at a time, if replacing worn tires, you should buy them in pairs and keep the pairs together (either both in front or both in back). Because the front tires do the steering and the majority of the braking, the best tires should be in front. When it's time to rotate crappy back tires to the front, that's the time to consider buying another pair.

I drive a heavy Cooper snow tire about 5 months of the year so rotating is easy for me when they are changed out. I call the other tires the "Three Seasons". :-)

I never thought to take it to an alignment shop to get their input on the wear.

I concern myself with properly balanced and inflated tires. I never rotate them. I do keep an eye on wear. When the front ones get worn a new pair is purchased and and the rear tires are moved to the front, new ones go to the back. The rear tires don't wear as quickly and are generally in great shape or I would put the new ones to the front. However if the rear tires are that worn it would be time for a new set of four anyway. Rear tires don't really wear that much unless you are doing burnouts and other silly stuff. I drive more than the average fool each year since I love driving. Managed to avoid flats and blowouts (other than picking up a nail and a slow leak and bending a rim on our legendary potholes) so I must be doing something right.

I did have one used car I bought many years ago lose all four tires within weeks. Tires looked brand new but the car hadn't been driven in some time. Rubber had become brittle and the new looking tread peeled right off as soon it got got warmed up. Figured it out on the second tire to go. LOL

"I never thought to take it to an alignment shop to get their input on the wear"

A tire store can do the same, you can too. Costco is a great place to get tires, they sell top quality products at good prices. Cars shouldn't need alignment more than every several years. Things that can throw off the alignment to require more frequent adjustment include bumping into curbs and parking stops, potholes, etc.

Here's an example of what tire wear tells you. All tires lose pressure and air needs to be added regularly. Checking monthly is a good idea. Under-inflation is dangerous - limits traction on the road - and causes premature wear on both outer edges, as shown below.

The two front were evenly worn down, all the way across as if I had never rotated them. If they are being rotated on a regular basis which I was doing, I would think the wear on all four tires would be even. Each two getting their turn on the front where most of the wear and tear happens. Does that make sense? Maybe that was all I was going to get out of these tires, about 25K. I did get prorated and get credit towards this new set which helps.

Yes, rotating spreads wear among all four tires so that together they last longer. 25K is pretty poor, were these tires on a new car?

New car tires are usually mediocre and less expensive models of name brands at the low end of "okay", less that "good".

Occasionally, one may find bargain priced tires on sale, however, not all bargain tires are bargains. One way to tell is to look at the Federal excise tax. This tax is based on the amount of rubber in the tire. New tires can be made with different tread depths, thus two tires of the same design and size can have different excise tax if their tread depths are different.

Both my boys are tire technicians. I can ask them how often you should get them rotated. I've had my "new" tires for 3 years and I think they're only been rotated once.