Tire Pressure Max

[Blenjar]

I was running on 38 psi, after my first maintenance, the guy said to drop it to 30 psi..

Not sure if I felt a difference but w/e

-- Blen

[brickhardmeat]

I read this story once about this guy who wasn't paying attention while inflating his tire. He over filled it big time. It blew up and a piece of the tire hit him in the neck and killed him.

[Blenjar]

I think its a good idea for black yars to make a PSI thread...how bout it!?

-- Blen

[BMGYaris]

come on bailout, calm down for a moment. When i said average I clearly meant the speed I am going the majority of the time, which is on the highway. Though it was the wrong term to use, you are correct.
i drive about 2/3 on the highway at about 80mph, in a particular hurry I go faster, and on a long road trip or if I have time I might do about 70. Around here we have long straight stretches of road with no police, its pretty moderate compared to others actually.
i get about 30-32 mpg which is good enough for me- i wouldn't mind going slower but I am always in a hurry to get to school in the morning, and yes I care about the emissions theoretically but i do little to contribute myself.

Now bailout , I know my primary point in my post was clear to you because you are obviously an intelligent person. My use of the word "Average" was inappropriate, true, but the heart of the content is still very valid and very real. If you are driving very conservatively and mainting speeds of under 50mph the majority of time with 60 psi, then the increased tire pressure will be much less likely to cause blow on you than if you are pushing your car hard, regularly maintaining 80 mph speeds and also have such a drastic increase in tire pressure. It may not happen all at once, but over months combining the average American driving style (especially college student driving styles, for example) with the 50% increase in air pressure could certainly cause for very serious tire problems. Though with your driving style that very well may not be the case.
I really have nothing against you but honestly, i know you understood my point and I know you recognize it as true and valid, so I say we look at the heart of a post and only make brief comments on small mistakes eh?

Also i completly agree that doing those speeds are more dangerous than doing 50% of the speed and raising your tire pressure 50%.

Finally, this thread was not about conserving fuel. This thread was about increasing stability--in particular at high speeds. That is why I am interested in it and apparently what the orginal poster is intersted in, so dont lose sight of the orignial focus.

[BMGYaris]

Originally Posted by Blenjar

I was running on 38 psi, after my first maintenance, the guy said to drop it to 30 psi..

Not sure if I felt a difference but w/e

-- Blen

Thats what I hate....I get conflicting information from you guys and from tech guys. And then the mentioned tech guy is wrong as well, I dont have it on hand but i think the manual says 32 all around, and then up it to 34 if your doing 100mph? something like that. Anyway, i dont know what to think, i just know my stability and control, in particular at over 70mph speeds, is seriously lacking, and im tired of it! with no money to make upgrades...this is my only real hope...damn it

[brickhardmeat]

Hey, BMG, calm down, -breathe- go get yourself a set of aftermarket wheels and upgrade the tires, you'll feel a difference, for now you'll be alright on what you've got just keep the pressure within a pound or few of what the manual says, that way you won't murder anybody

I think it may be the suspension more than the tire pressure that is truly bugging you. I know I hated the way the car felt stock.




I missed the part about the money. Start saving, this car needs a few upgrades. It's still a great car though.

[Blenjar]

Well I'm running on different rims weight, tires are heavier and stuff...kinda hard...wtf...this wil lbe a lot of work for Black Yaris to compile :p

-- Blen

[BMGYaris]

Originally Posted by brickhardmeat

I missed the part about the money. Start saving, this car needs a few upgrades. It's still a great car though.

Yea, im pretty fking booked up as far as money is concerned....25k debt for school, owe my gf 500bucks my parents 2.5k and im supposed to propose to my gf this summer...fucking ring.....and like I have mentioned in previous post...she is japanese, which means trips to japan...then an international wedding in 1 1/2 years...all on a future elementary school teachers salary...lol i think my car might be stock for a LONG time....lol...well eventually i will deal with the tires and maybe suspension, and one day a nav so i dont get lost traveling with my woman on the weekends..but its not quite time for that yet.....

[AustinYaris]

I think (at least hope) we're all intelligent to make our own decisions on our tire pressure. As a fellow hypermiler like BailOut, I plan to pump my tires to the hypermiling community's recommended tirewall listed max psi. Even though my personal research has shown BailOut's suggestion of 60psi safe, I probably won't pump it up all the way to 60. Although mpg is one of my goals, I also want to maintain a comfortable ride.

It all depends on what you want to maximize... mpg, ride comfort, stability, breaking... And do your own research before making a decision before blindly listening to anything anyone has said on this board.

And no need to make snide comments towards others on the board, especially if you haven't done your research.

Just my 2 cents.

[Yaris Revenge]

I'm not gonna' rag on over-inflation... hypermiling is just plain weird in the first place. Here's my math, please correct me if it's wrong (I suck at math).

Yaris fuel capacity= 11 gallons
Cost of fuel= let's say a nice even $3/gallon
EPA estimate highway= 40mpg
Estimated range for normal driving then= 440 miles
BailOut's range @ 44mpg= 484 miles

BailOut travels 44 miles further on a tank of gas. That's roughly one gallon of fuel he saved compared to a normal driver.

Back to the top, one gallon of fuel costs $3.

Using all the crazy and sometimes dangerous driving techniques that hypermilers use, the driver has managed to save a measly $3 per fillup.

Using this math (which again, could be wrong) I just don't see how anyone can justify dangerous driving techniques. I say drive reasonably and give up one tall (aka "small") Caramel Macchiato from Starbucks. You'd save the same amount.

~YR

[eTiMaGo]

Well the EPA estimate is very generous, look at the fuel economy thread in the main forum, real-world consumption is probably more like 35MPG. So, it's more of a 100 miles extra compared to the average driver, which equates to almost 3 gallons, so let's say $8 per fillup.

Refill once a week and you're talking about saving up $416 in a year. Not a lot of money to some, but a penny saved is a penny earned to others

But yeah, that being said, this technique should really be for those who are very serious about squeezing every last mile out of their fuel, especially if they drive very long distances. Needs a very big disclaimer about the downsides of this too

[eco]

I will never agree with 60 psi on a 44 psi max tire.I will say this,I try to find the exact pressure for stability,comfort and gas savings and still be safe,I use37psi on a 50psi max tire,my temperature may hit 44psi in the course of a 1hour trip,still no where near 50psi for my tire,I have just found this to be the sweet spot for all 3 stab.,com.,gas sav.,.When I was using the the 44psi max tire I used 38psi,that was the sweet spot for my setup,its all trial and error,but never exceed 44psi when tire is checked cold,the tire will hold 44 cold,and can withstand the increase of psi when the tire is heated up.
Remeber folks,there is no tire making procedure that is 100% all the time,if tire is faulty,and you exceed max psi,then you will more then likely have a problem,think about it.

[Nimble]

Tires are not meant to be run at MAX PSI! Are you kidding me? Seriously, the poster saying he runs SIXTY LBS has got to be kidding. 34 tops on most passenger tires, and 40 on very low profile ones.

[BMGYaris]

Originally Posted by Yaris Revenge

EPA estimate highway= 40mpg


Using this math (which again, could be wrong) I just don't see how anyone can justify dangerous driving techniques.

~YR

Hey, well first off I wanted to say that while I do not condone the hypermilling techniques.
Nontheless. The risk of overinflation are pretty simple, and if you do a search around the internet you will find that it is not nearly as dangerous as underinflation. The risk of overinflatoin, as best I can tell are :

1) The thread in the center of the tire will wear out more quickly
2) That it will puncture a bit easier
3) Once the threads are worn down it will puncture much more easily.

Now, because of his hyper milling attitude he has changed other things as well:

1) he tries to maintain about 48mph, or so i hear, and even slower
2) he plans ahead, watches traffic, and is constantly aware of obstacles, pot holes, and general hazards--he takes driving seriously, not fucking around.

I dont have any statistics, but im pretty sure that by cutting back on his speed so drastically and by having his extra care attitude and concern for cautious, intelligent and safe driving on the road--the very concern that caused him to pump up his tires--will in fact make him and everyone else around him much safer. If you had the percentages I am sure that he averages out to be a much safer driver than myself and every other person I know, just based on increased risk of tire blow outs and decreased risk of highspeed crashes.

However, there is another major increase in safety, there is no doubt in my mind that this mother fucker checks his god damn tires every fucking morning. You wont find him without threads on his wheels--but you might find me. You wont find him underinflated--but you might find me. And most people--but not him, because of his overinflation, and his general attitude, I am sure he is much safer and his car is in prestine condition. I think---but i cant find any actual stats or solid information on overinflation--everything focuses on underinflation. still, that is based on what i have gathered thus far, and it seems reasonable.

[BMGYaris]

Originally Posted by Yaris Revenge

I'm not gonna' rag on over-inflation... hypermiling is just plain weird in the first place. Here's my math, please correct me if it's wrong (I suck at math).

Yaris fuel capacity= 11 gallons
Cost of fuel= let's say a nice even $3/gallon
EPA estimate highway= 40mpg


~YR

_______________

As for your numbers, new EPA ratings put the yaris at 36 highway and 32 combined
http://www.fueleconomy.gov/feg/calcu...umn=1&id=22750

That means that if our man is using highway figures it is just as the frenchman prooposed, and if he is giving you combined then it is even better. Also, but it in terms of hours worked. if he can save 9 bucks at the fill up, thats going to be more than 1 hour of work saved per tank, which is significant (for me as a student I only make 7 bucks an hour:), you can figure out your own).


But, and i think you will like this one if your with me, Say at EPA ratings at 11 gallons with 36mpg, we can drive 396 miles per tank right? now (lets just say we are doing the whole tank on the highway since we are using the highway EPA figures) so we average 80mph. At 80 mph it will take us 396/80=4 hrs 57 minutes. Now if he averages 50 mph it will take him 396/50=7hrs 55min.

He lost three hours, and he still has 2.9 gallons of gas left, around here that is about 9 bucks, and my 1 hour is usually worth more than 3 bucks to me so in my mind, that isnt worth it. Of course, in a heavy commute is when I imagine his numbers shine the best because they will usually take the same time, but you can work those out on your own, im tired of this now:)

At any rate, i think he is probably balancing it out more than equally wherein safety is concerned.

[Yaris Revenge]

Yeah, I agree BMG. I'm not crazy about the over-inflation, but that part isn't really what concerns me so much about hypermiling. The techniques that I find more worrisome are speeding onto downhill offramps/onramps to maintain momentum, drafting (aka tailgating!), killing the engine while running downhill (which kills power brakes and steering on most cars), etc. That just seems a little crazy.

I fully expect that later down the road hypermiling will be recognized as a disease, like alcoholism, that affects addictive personalities. Some people can get into it and have a little fun, but know when to quit, while others go totally insane, like that other guy mentioned in the article. I've read about him before... never runs AC, actually pushes his car out into the road to save that extra 20 feet, etc.

~YR

[BMGYaris]

hum, i think at that point its obviously not financial. But if it was a matter of envrionmental concerns then surely other things that he is doing in his life have such a greater impact on the environment that those 20 feet are completly irrelevant. so i figure it cant really be about environmental concern or he would be out living on horse back and nature...i wonder what other motive it could be....

[AustinYaris]

Originally Posted by Yaris Revenge

BailOut's range @ 44mpg= 484 miles

BailOut travels 44 miles further on a tank of gas. That's roughly one gallon of fuel he saved compared to a normal driver.

~YR

YarisRevenge,

Just a quick note: BailOut has improved his MPG to 49 lately. 44 is an average of all his tanks from the very beginning.

There are lot of more skilled hypermilers who get 59MPG on a regular gas ACCORD for example. So there's actually LOTS of room for improvement on our Yarises.


Also a note on hypermiling... yes, I agree with you guys. Some of the techniques are not very safe...hypermilers are aware of this, and we'd be the first ones to admit it. But I would have to say it's still much safer than people driving while talking on their cell phones.

Also, at least for me, I don't do "all this work" to get save just a couple of bucks. I really enjoy it more as a hobby, a sport, the challenge of trying to reach 50+mpg.