screw more psi in the tires.

[GeneW]

Originally Posted by BailOut

1) Tire companies are one of the worst places to get information about their products. The same holds true of any other manufacturer of consumable goods. While they have to do enough to meet minimum safety standards and product longevity everything is secondary to their primary goal of selling you more of said product through repeated need.

The manufacturer and seller must make a good sufficient enough to meet customer demand but no more so. To do so is irrational.

Tires, being a consumer good, are subject to all sorts of consumer and safety regulations. There is also the Tort aspect. It's a jungle out there in Courtrooms.

It's always wiser to give yourself lots of wiggle room with specifications. Safety margins, variations in supply and processes, and so on. This allows you as a defendant to stack the odds in your favor with Juries. So no, you will not reveal to the customer the outer limits of performance, not in a nation where people can spill hot drinks on themselves and win judgments in Court.

I work in manufacturing, but not for the consumer market. Our customers are large entities which expect good specification and will train their staff about safety. However I have made consumer goods and know the hazards of such work.

Originally Posted by BailOut

2) Automobile manufacturer's tests for tire pressure are aimed primarily and almost wholly at passenger comfort rather than accident avoidance, product longevity or fuel efficiency.

This makes sense - most consumers will judge a tire based upon its handling and "feel" than on the more pragmatic virtues that Brian discusses. Since the name of the game is market competition you have to adapt to the market or perish to competition.

As someone who drives on some of the worst roads in North America I never ever will go above the rated inflation pressures. Some of us drive on better roads or have other values than not having blowouts after passing through a gigantic pothole.

Gene

[supmet]

@bailout

60 psi WILL increase tire wear and WILL decrease traction. end of story. I'm not arguing this one. Go find me one auto crosser who runs 60 psi on their yaris.

and again, the tunnel vision of hypermiling is coming into play. What about all the added stress on suspension, suspension mounts, engine mounts, transmission mounts, interior trim pieces, pretty much the entire car???

I suppose the 20 dollars a year(again) you are saving will pay for all of that??

If you want the all important MPG, and that's ALL you are worried about, listen to every word bailout says. If you are interested in the total cost of something, I suggest doing your own research.

[BailOut]

Originally Posted by supmet

Go find me one auto crosser who runs 60 psi on their yaris.

This is the fuel economy forum. For discussions on autocross please see the racing forum. If you can get any of the folks over there to test anything other than a butt dyno please let me know.

Originally Posted by supmet

What about all the added stress on suspension, suspension mounts, engine mounts, transmission mounts, interior trim pieces, pretty much the entire car???

What about them? In over 6 million miles of road testing not one driver has ever reported early suspension component replacement or interior trim pieces jumping off or mounts/bushings failing. Those kinds of events are usually related to things like autocross.

Originally Posted by supmet

I suppose the 20 dollars a year(again) you are saving will pay for all of that??

Please show your math as I cannot tell when your amount of $20 came from. Most Yaris drivers average 32 MPG. I average about 48. Over the 17k miles I drive each year that saves 177 gallons of fuel. At a price of $2.25 per gallon that saves me about $400 per year.



supmet, I'm not sure why you continue to hang out in the fuel economy forum as you don't seem to have much interest in it and you consistently deride the practices of those that do. You seem to thrive only on misinformation and alarmism and continue to do so in the face of mountains of data and practical examples that contradict you. Please feel free to frequent other parts of the forums that are more in line with your personality and personal desires.

[supmet]

Originally Posted by BailOut

This is the fuel economy forum. For discussions on autocross please see the racing forum. If you can get any of the folks over there to test anything other than a butt dyno please let me know.

You are the one the said you get better handling at 60 psi than 32. Don't back out now!

Originally Posted by BailOut

What about them? In over 6 million miles of road testing not one driver has ever reported early suspension component replacement or interior trim pieces jumping off or mounts/bushings failing. Those kinds of events are usually related to things like autocross.

Uhm, because hypermilers don't report ANYTHING but MPG? And most of the cars that you use for your "scientific data" haven't been on the road long enough to see the damage you are doing.

Its pretty much elementary physics. You aren't absorbing as much energy with the tires = more energy gets transferred into the suspension and chassis. To completely write this off is irresponsible.

Originally Posted by BailOut

Please show your math as I cannot tell when your amount of $20 came from. Most Yaris drivers average 32 MPG. I average about 48. Over the 17k miles I drive each year that saves 177 gallons of fuel. At a price of $2.25 per gallon that saves me about $400 per year.

You are the king of fuzzy math, and that's my biggest problem with you. Ok, you save 400 dollars a year over the average, but that includes EVERYTHING YOU DO, not just over inflating your tires. 20 dollars may be low, but I'm betting you'd still have to go years to cover the cost of a SINGLE engine mount.

Originally Posted by BailOut

supmet, I'm not sure why you continue to hang out in the fuel economy forum as you don't seem to have much interest in it and you consistently deride the practices of those that do. You seem to thrive only on misinformation and alarmism and continue to do so in the face of mountains of data and practical examples that contradict you. Please feel free to frequent other parts of the forums that are more in line with your personality and personal desires.

What mountains of data? I keep hearing about these 6 million miles of data, but I bet you don't have complete service records for any of the vehicles included in the data set.

And I like getting better gas mileage. That's why I post here. I just like to get the WHOLE story - not the tunnel vision story that hypermilers THRIVE on.

[voodoo22]

Originally Posted by supmet

And I like getting better gas mileage. That's why I post here. I just like to get the WHOLE story - not the tunnel vision story that hypermilers THRIVE on.

Tunnel vision applies to people who tailgate, race to the next light and drive only with themselves in mind. Tunnel vision applies to the sheep who follow without questioning and crying that the sky is falling anytime someone claims the earth is not flat.

People whom you label hypermilers can only attain optimal performance by paying attention to their entire environment, maximizing their safety level while enhancing their mpg.

You can say what you want, but until you have experience on both sides of the fence you're simply making statements with nothing to back them up but you're opinion.

Fact is, Brian is right and you're wrong. You don't have to accept that, but hopefully your ignorance will not mislead others interested in facts proven by real world experience.

For people who want to learn and not buy into conjecture; check out posts by Brian and check out cleanmpg.

[1stToyota]

Originally Posted by supmet

@bailout

60 psi WILL increase tire wear and WILL decrease traction. end of story. I'm not arguing this one. Go find me one auto crosser who runs 60 psi on their yaris.

and again, the tunnel vision of hypermiling is coming into play. What about all the added stress on suspension, suspension mounts, engine mounts, transmission mounts, interior trim pieces, pretty much the entire car???

I suppose the 20 dollars a year(again) you are saving will pay for all of that??

If you want the all important MPG, and that's ALL you are worried about, listen to every word bailout says. If you are interested in the total cost of something, I suggest doing your own research.

True. 60psi is all about getting best mpg by going with extreme measures, has nothing to do with keeping wear, handling, braking, mpg and comfort levels all at normal and safe levels.

[GeneW]

Brian is especially correct about hypermilers having different needs from tires than the usual consumer. A tire which is inflated to 60psi is probably not safe for use at speeds over, let's say, sixty miles an hour. To the hypermiler such speeds are beyond the pale, and hence for them a higher pressure is safer.

Gene

[07WYarisRS]

here's a thought... go talk to the guys at the tire shops, see what they say about tires that are over or under inflated... ask them if it affects the mileage of the tires..
I have no intrest in what the local kids are doing and what they think work.. I want facts... I have yet to have my tire suppliers tell me to double my air pressure to increase my mileage... why? because what I save in a year running on over inflated tires i'll spend on tires the following year when these are pooched.

tire pressure is very important...
how do i know?
I'm a mechanic (motorcycle) Sure most of my background is racing, bikes and offroad but tires are tires people.
The number one cause of tire damage on motorcycles is caused by incorrect tire pressure, cupping and tire deformation is most common.
I can't tell you how many times owners have come to me complaining of poor hadling or poor tire life...guess what...tire pressure is usually the cause or part of the cause.
then there is the traction issue, with a motocycle even 2-3 psi cam make a HUGE difference. Usually not as noticable at slow speed when the foot print/contact patch is the largest and tire temps are cooler. The same applies to Auto tires though

A tire at 60psi ..what is that at highway speeds when the air temps increase...its dangerous. if it were not for the steel belts in the tire holding it together it would likely explode when you hit a pot hole. Do you really think the tire remains the same shape at slow speeds as they do at highway speeds/

I enjoy the great fuel mileage, but come on... if it means that much to you go with a smaller set of 13" pie cutter tires like the geo/sprints had.

BTW a simple tire tread depth gauge will easily show you what over inflating tires does as far as uneven wear.. you can't always see it just standing there with you arms folded staring at the tire sayin nope no wear yet!
Most people never notice tire cupping or a shifting belt until they have a bald patch or the tire deforms and starts causing vibrations

FWIW I followed the mileage group on the Ford focus forums... I had an 03 with 155km... I JUST got my second set of tires last fall at 120,000km. I ran 35psi The hypermilers on the same sight running even 44-50psi were getting 60-80k km to a set.
figure that into the math... with the 1-2mpg less I may have got and what I saved using synthetics etc.. I bet it cost more buyin tires every 2 years for them.

[Rick]

Strange, when I took my Cobra through the Bondurant school of high performance driving they REQUIRED that my tires be inflated to sidewall max. Not negotiable.

I have the stock Goodyears that Toyota puts on the 15" steelies. My three-door hatch is a hopeless, hapless disgusting pig in the corners with 32 psi in the tires. The TRD rear sway bar helped some, but running 51 psi front and 50 psi rear makes it dry corner like it's on rails. That's only six psi higher than sidewall max. These tires are wearing evenly so far as well. I'm not saying that any old tire can accomplish that though.

Also, most of the pothole related tire failures I've seen were the result of the sidewall being pinched (crushed) between the road and the wheel. Higher tire pressures should make that harder to accomplish.

[thebarber]

Originally Posted by Rick

Strange, when I took my Cobra through the Bondurant school of high performance driving they REQUIRED that my tires be inflated to sidewall max. Not negotiable.

i was under the impression you raise the pressure a bit so the sidewalls flex less under heavy cornering...im kinda surprised they put it at the max....but maybe the tires have a level of safety built into the "max pressure"?

[GeneW]

Originally Posted by Rick

Strange, when I took my Cobra through the Bondurant school of high performance driving they REQUIRED that my tires be inflated to sidewall max. Not negotiable.

Bet you had high heat rated tires too. It helps.

Originally Posted by Rick

Also, most of the pothole related tire failures I've seen were the result of the sidewall being pinched (crushed) between the road and the wheel. Higher tire pressures should make that harder to accomplish.

If you're talking catastophic failures I could not say. If you're talking belts breaking, that's another topic. Don't know if higher pressures would help or not. I pays my money and takes my chances at factory pressure settings.

[b_hickman11]

I think Obama is behind it all.....

[ka0sx]

Originally Posted by b_hickman11

I think Obama is behind it all.....

lol

[SpaceShot]

Just an observation:

The TPWS in the Yaris seems to trigger somewhere down around 25 psi, and there doesn't seem to be any upper limit. (purely a limit warning system and not an active monitoring)

Thus for myself, I am more concerned about letting them get too low, than running a few psi high.

[1stToyota]

I think I'd rather be warned after losing 6 or 7 lbs vs losing 36 or 37 lbs (running 32psi instead of 60psi)

[SailDesign]

Originally Posted by thebarber

k, just was looking at my tires from last summer....was running 35psi most of the summer and into the fall (maybe 20,000kms (12000mi)) and there is noticeably more wear in the center of the tire than on the outside and inside shoulders.

ill be going back to 32psi

You're obviuosly not "enjoying" the corners enough.
I keep mine at 36 cold to increase sidewall stiffness (for cornering), and decrease wind movement.
If you corner harder, the outer edges will wear the same as the centre.
Each to his or her own, however. I set my car the way I like it, and fully hope everyone else does the same (i.e. how THEY like it, not how their friends tell them it should be)

[aclark246]

Originally Posted by SailDesign

Each to his or her own, however. I set my car the way I like it, and fully hope everyone else does the same (i.e. how THEY like it, not how their friends tell them it should be)

+1
Spoken like a true Rhode Islander!

I doubt that any of the belligerents here will ever agree on this issue, or more importantly convince the other side. I recognize that both sides only want what is best for us fellow yaris drivers and want to share their info and educated opinions on the topic. But at the point where it shifts from a positive sharing of information and opinions to a negative, mudslinging argument (from whichever side it may be...) I second the solution of "to each his own."

On a side note, I personally keep my OEM tires at or around 44 psi. As weird as it is, I prefer the comfort of 44 as opposed to 32, and that is why I keep it there. I have not noticed any uneven or untimely wear on my tires, although as someone mentioned previously, I am not measuring the wear scientifically. I have noticed a significant change/decrease in fuel economy the times my tires have been around 32psi, so I also second Bailout. (And that is my contribution to forming any kind of unscientific consensus.)

[Kaotic Lazagna]

Seems like the police is on the side of having the tire wall max rating rather than the door jamb rating.

http://cardealerforums.com/alt-autos...rspective.html

A good read.