Follow up on my Tire Replacement Strategy thread


#1

In my “Tire Replacement Strategy?” thread I got varying answers as to whether to replace 2 or all 4 (original) tires on my 2007 Yaris.

I ended up replacing all 4 tires. The rear tires looked as though they still had almost as much tread as they did when they were new but the front tires were one step away from being bald.

I know I said in my other post that there was no cracking and the rear tires looked great - but I took a much closer look at the tires and could see fine hairline cracks in the sidewall and around some of the tread. There were so many of those cracks that it looked like a chunk could possibly fly off if I were to hit a pothole - and eventually maybe even without hitting anything. I didn’t see any of this when I first looked because I wasn’t up as close as I needed to be.

The tires (RE92 Bridgestones) are at least 7 years old and my car is kept outside - although the climate is very moderate here in Redwood City CA.

The shop that was recommended by tirerack and here at cartalk put the new (General Altimax RT43) tires on in about 40 minutes. I immediately experienced a smoother and quieter ride and the handling seems a slightly better than before.

In closing, thanks for all of the good advice and I have one more question. The tires are supposed to be inflated to 32 PSI according to the manual and the template on the door. I checked each tire after getting home (and letting it sit for a couple hours) and each tire was set at 28 PSI. It is no big deal to me and very simple to correct but I still wonder why they did that. I think I’ve written here before that I’ve never bought new tires that had the recommended inflation - ever!

Is there some logic in that? Is a difference of 4 PSI statistically insignificant? : ) I know some people keep their tires over inflated or under inflated for reasons that make sense to them but I’m just curious why the shop wouldn’t follow the template inside the door.

I know I could ask them why they did what they did but I prefer right now to hear the opinions of people here.

Thanks in advance for any comments.


#2

A drop of 4 psi can affect gas mileage. I typically have mine 2-4 psi above the placard recommendation. Oh, and, to get the most out of this set of tires, rotate them occasionally. I rotate my sports car tires every 5000, SUV about every 8000.


#3

I’ll go a little off topic . . .

My late aunt owned a house in Redwood City

As I recall, the real estate market there was absolutely insane

I couldn’t ever think of buying there


#4

Four PSI is significant to me. As to differences in the pressure maybe there’s a variation between your gauge and the one the tire shop used.
I think you did the right thing by replacing all 4 tires because microscopic dry rot cracks can snowball quickly and become large ones; or holes… :slight_smile:

Even with moderate temps, sunlight can be brutal on rubber.

I usually run all of my tires at about 34-35 with never a problem.

Along with the OT housing situation, consider the house next door to me that just sold 2 weeks ago.
Three BR brick about 3000 sq. ft roughly 35 years old, 2 Bath, 2 car attached garage, family room, meticulously maintained always and hang the expense, on 1.4 landscaped acres with a 40 X 60 slant wall shop building/large overhead door on a concrete pad on a corner lot. Went for 99k and it was partially furnished…

Wonder what that would go for in Redwood City…


#5

I think you’ll get a little softer ride with the lower pressure but no big deal. In Minnesota when it got cold out, those 28# would be down to 24# or so which would be too low. In your climate though there won’t be much change with the weather but go ahead and pump them up a little.

I think you’ll like the Generals. That’s what I put on my G6. Quiet, smooth, and good in rain and snow. They are a good lower cost compromise if you don’t need or want a performance tire, and are made in the US.


#6

The low pressures aside, I think your experience provides a valid point about there being much more to a tire than tread depth and design. Even if you hadn’t noticed the hairline cracks the rubber has hardened and lost much of its pliability (and I would also assume strength) after 7 years.

In answer to the off-topic housing comment, @ok4450‌ you couldn’t buy a brick schitthouse with 2 squares of toilet paper for $99K around here. My friend is going through a divorce now, apparently the going rent for an 800 sq ft 2 bedroom apartment is $1800/month plus utilities.


#7

@asemaster, you’re dead on about tires losing their pliability. Some years ago I had a set of Kellys on my old Lincoln. The tires were aged but had about 90% of their tread.

Those tires were pure death. Even with the slightest bit of dampness on the pavement (no water pooling at all) that car would skate all over the highway at 55 MPH and on several occasions the car spun the rear tires and fishtailed just from the simple act of removing my foot from the brake pedal and before even depressing the accelerator pedal.

Housing is way cheaper across most of OK than it is in other parts of the country. My youngest son was telling me the other day he has a chance to buy a 2500 sq. ft. home on 5 acres outside of the city where he lives for 50k and even that may be negotiable.

Property taxes are usually cheap also in most areas. Mine runs about 180 bucks a year. :slight_smile:


#8

$180 a year, for what, a car registration? I live in what I admit is a fine large house, 12 years old, 15,000 sq ft lot, but still just a house in a nice family neighborhood. $5200/year.


#9

Nope, 180 a year total on my home property taxes. The home next door that I mentioned? The total taxes on that place are less than 1200 a year and the only reason it’s even that high is because of the roughly 2500 sq. ft. shop building.

To keep it auto related, the ex-neighbor now also kept a very nice '51 Plymouth Sedan and very nice 2 Door Hudson Hornet in that shop building. He said the toughest part of restoring that Plymouth was finding that multi-colored Houndstooth fabric for the seats.
I love old Mopars but really drooled over that Hudson… :slight_smile:


#10

There are some shops that seem to think that every car and every tire going out of their shop should have the same pressure, so in this case, I think that the OP’s tire shop probably inflates everyone’s tires to 28 lbs. After all, it is much easier to do that, rather than having to consult a chart or to look at the label on the door jamb!

Seriously, however, under-inflation will do several things, none of which are desirable.
It will:
Reduce your gas mileage
Reduce the tread life of the tires
Reduce the handling ability of the car
and
Reduce the load-carrying capacity of the tires.

So, when the tires are cold (after sitting for a few hours), make sure that they are inflated to at least the same pressure as is specified on the label affixed to the door jamb. And, if you want to inflate them 2 or 3 lbs over the specified pressure, that will be even better in terms of gas mileage, tread wear, handling, and load-carrying ability.

And…don’t forget to rotate the tires on a consistent basis–every 5k miles or every 7.5k miles.


#11

I think the door jamb pressure ratings are specific to the tire that was installed on the car from the factory. Once you change brands I think you should follow what it says on the sidewall of the tire. Never ever inflate over the max pressure. This will risk blowout, and while reducing rolling resistance and thus increasing mpg, youll be wearing out the center of the tread faster, and youll be shrinking the contact patch to the road making it more dangerous in rain, and in emergency braking.


#12

@fender1325, those tires can wind up on any number of cars or trucks. That max PSI on the side of the tire is what the tire can handle. But the placard tire pressure is based on several factors of the car, including weight, to maximize contact patch. I do make minimal adjustments from the placard pressures, but never to max PSI. Also, using max PSI takes away the safety factor from the tire design. A tire can easily see pressure increases from 5 to 6 PSI from ambient temperature increase through the day and heat from driving. If you start out at max PSI, the tires can easily see more that and you risk tire blowout. For my sports car, that would be an overinflation of 16 PSI, way too much. The good folks at www.tirerack.com have some excellent articles on tire pressure. http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=196
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=1


#13

"Once you change brands I think you should follow what it says on the sidewall of the tire"

NO!!!


#14

“Once you change brands I think you should follow what it says on the sidewall of the tire”

Absolutely not!! I agree with @VDCdriver 100% here. That kind of thinking is nuts…and very dangerous to boot. I guess you don’t remember the Ford Explorer problems with tires some years back.


#15

Fender1325 said: “…I think the door jamb pressure ratings are specific to the tire that was installed on the car from the factory. Once you change brands I think you should follow what it says on the sidewall of the tire. …”

Here’s why this this wrong: While changing make and model of tire can change the way the car “feels”, it’s the difference in the construction that makes this change. ANY tire can be redesigned to ride softer or handle better just be adjusting certain components in the tire.

But inflation pressure is very, very much a factor in load carrying capacity - and that is how the car manufacturers set their specs. They then force the tire manufacturers to re-engineer their tires to fit what ride and handling compromise the vehicle engineers want.

And as has been pointed out, a tire manufacturer doesn’t know what vehicle their tire is going to go on,. so they publish a MAX pressure. It’s not a recommendation. Call the tire manufacturer and ask what pressure they recommend and you will find they ALL point to the vehicle manufacturer’s specs!


#16

“a tire manufacturer doesn’t know what vehicle their tire is going to go on,. so they publish a MAX pressure. It’s not a recommendation”

I’m glad that CapriRacer–our resident tire expert–has logged onto this part of the discussion to reinforce what missileman and I said regarding the error in fender1325’s advice.

In order to help fender1325 understand why his advice is wrong, let’s try to put this in human terms. If your doctor stated that he did not want to see your blood pressure going over…let’s say…140/85…that doesn’t mean that he is recommending 140/85 as a healthy blood pressure. Rather, he is saying that anything over those numbers would be dangerous.

Similarly, if the XYZ tire company embosses the words, Maximum inflation pressure=50 lbs on the sidewall of their tire, that doesn’t mean that they are recommending that pressure. Instead, they are warning that some dire circumstances can result from exceeding that pressure.

The OP should use ONLY the tire inflation pressures listed on the label affixed to the driver’s door jamb, and might want to consider–possibly–adding 2 or 3 lbs more than the mfr’s recommended pressure, in the interests of better handling, better gas mileage, and longer tread life.

However, I am willing to wager that the difference between the car mfr’s recommended pressure and the maximum pressure embossed on the tire’s sidewall is substantially more than 2 or 3 lbs, and is more likely to be something on the order of 12 or 15 lbs. Exceeding the car maker’s recommended inflation pressure by 12 lbs or more will likely result in…oversteer…less traction on wet surfaces…excessive tread wear in the center of the tire’s tread…and possibly damage to ball joints.


#17

If you inflate to max, the tire will wear in the center. The ride will be harsh. Wet weather traction will be reduced. The handling will be crap and every bump will throw the car around. The steering will seem to skate around. Always stick to the sticker.


#18

Woweeeee! I did say never ever inflate over max pressure - that does not mean “inflate it to what it says on the sidewall.”

I suppose my thinking is because on my old mustang i went from a 16 inch rim to an 18 with lower profile tires and that changed the whole thing. I can see if you go with OEM sizing itd be better to follow the door jamb pressure instructions. I still however disagree with adding 2-3 lbs over the manufacturer’s instructions on this one.


#19

@Fender1325‌

I respectfully disagree with you

There can be 10 or 15psi, or more, difference between the door jamb pressure ratings and the tire’s maximum allowable pressure, which is on the sidewall

I’ve seen guys routinely inflate to the max pressure listed on the sidewall . . . because they were literally too stupid to open the owner’s manual or look on the doorjamb . . . and the result was drastically reduced tire life, because the center of the tread wore out within an extremely short time

To sum it up, I think you should always inflate to the pressures listed on the doorjamb, because that is what the vehicle manufacturer has determined to be the correct pressure for the vehicle, when using the stock tire size. I’m talking about a situation where only 1 person is sitting in the car, and not carrying a heavy load . . . because that is how most cars are probably driven.

I realize that a fully loaded vehicle going on a family vacation may require different pressures

I’m NOT talking about those early Ford Exploders that rolled over. That might be a different situation

And I also realize that weekend racers and off-road guys have good reason for not adhering to the door jamb stickers


#20

Thanks for all of the helpful input and advice.

FYI - a house around the corner from me - 1430 sq ft - 2 bedrooms / 1 bath / 7400 sq ft lot - sold for 1.2 million in June. I was shocked.

The average rent in my area is $3500.00 / month.

That could buy a lot of tires.