possible for bad tire to act like a warped rotor?

Absolutely. A tire slightly out of round, a tire with a bubble, a separated belt... they can all make it feel like something's wrong with the brakes under various conditions, particularly when it's a "borderline" condition. As they get worse, it can get to be screamingly obvious that it's the tire, but when it's "just a little" off, well...

Definitely possible, especially if its a flaw like a separated/broken belt on a front tire, so that when the tire gets a braking load on it it deforms in the area of the broken belt.

Don Bruder wrote in news:470b814e$0$14104 $ snipped-for-privacy@news.sonic.net:

...a badly mounted tire that does not spin true...

That's are far more common than the defects you mention.

The tire was patched at least once (lost track of how many times I'd had which tire patched, along with rotations...) so it had been dismounted and remounted, but it seemed to develop over time, not appear all of a sudden after it was patched. I didn't see any bubbles either, but then again these were Goodyear Integrity which have to be the most s**te tires I've ever driven on, even worse than the Continental all-seasons that came on my '02 GTI.

Why do mfgrs. spec such crap tires for new cars? I guess I can kind of understand the Impala, although these were so bad they were dangerous, but VW spec'ing those awful Contis for the GTI makes me shake my head.

nate

Tires can be a very important, but elusive, issue. I gave up on Goodyear and Firestone years ago... Maybe they have improved in the interim.

I buy Michelins,usually.

The issue of pulsation in the front is easily confused with brake issues, tire issues, suspension wear, and more.

What some perceive as pulsation may be hard to pin down. It is not always as it seems.

when you make 100,000 cars, and need 400,000 tires a nickel or a dime multiplied by 400,000 adds up.

whoever bids cheapest, supplies tires

Sure, I know this, but wouldn't $0.10 a car be a small price to pay for a car that actually performs to the capabilities of its drivetrain and suspension? Some of us shop for cars primarily on factors other than price (although "can I afford it" certainly is a concern) and test driving a car where it's clear the bean counters won is definitely a turnoff.

nate

YOU paying a dime extra for ONE car is meaningless - It isn't the SELL price, it's the MAKE price that the car companies are worried about. To you and me, it's an extra dime. Big fat flippin' deal. To them, it's an extra 40 grand over a 100K unit production run. I have to agree with *BOTH* sides, actually - From the buyer's side,It sucks having to deal with the bean-counters, but when you look at things realistically, the makers are in business to make as much money as they can, while spending as little as possible in the process. Basic economics in action.

But what it means is that as long as ONE manufacturer still makes a decent product, the bean-counters get nothing from me - I either buy from the good mfgr. or buy used.

nate

If you sell a million cars and can save 2.75$ on each tire it adds up. John Deloreon wrote a book about his time with GM (years ago now) and the development of the Vega. They tested the car with a couple different sizes of tires and found that it made a big difference in how the car road/handled. (no surprise). But it would have cost them something like $4 more for a car that was going to sell for around $4000 (is that right, I can't remember). The top dogs would not let him use the better tires for the extra $4.

I think that is one of the big areas where the "Big three" screwed up over the years. It seems like they economize in areas they shouldn't just because they can. You could buy a Caprice back in the 80's with or without the F41 suspension option. It cost about $50. It provided stiffer springs, shocks, and a rear anti-roll bar. It turned teh car from a mushy bathtub handling boat into one of the best handling cars on the road (for it's type). Every car review,almost without exception, tested the non-F41 equipped Caprice and bitched about the poor handling. Having driven both kinds, I just cannot imagine the average driver would have preferred the weak kneed flabby handling version over the F41 version yet ......

That's not the complete picture. If saving that dime means that every magazine that tests the car complains that the accelerator pedal is awkward on a long trip (because they saved a dime by making it too short), how many sales do they lose?? If every magazine complains taht they couldn't stop the car quickly or keep it in the skid pad over 50 mph (when the competition is doing 60), how many sales do they lose? If they save $1.50 by using switches for the lights and AC that make a cheap sounding "click" and feel like they are going to break, how many sales to they lose when people try them in the show room and think "This feels cheap". When I was looking for an SUV back in 92 I looked at Explorers and Blazers. I looked at new Blazers at a tent sale and every one of them had surface rust around the bolts on the radiator support. That turned me off to even considering them further and I bought an Explorer (still no rust). Someone at GM probably saved $0.12 by not dipping that cross member in the anti rust bath on the theory that it was "up high" and didn't need the rust protection. (I"m just guessing of course).

Sometimes the belts get installed crooked. It can make the tire waddle. You usually feel it the most on a smooth road when you are going around 20 miles per hour. The car feels like it's waddling from side to side. One of the first things to check for with new tires.