Zzyzx

WOW....what a load of BS from that original site...

Heres what aTire MFG has to say about tire PSI

http://www.goodyeartires.com/kyt/maintaningATire/


simply put, the proper tire PSI for your car is based on the weight of the vehicle.

jackburton

iTrader: (1)

Might as well do what Hunter S. thompson did and run 100psi so he could do 180s in the shark.

You only have to up tire psi like one or two psi for every two inches you increase rims size, at least is some where around there. And you look on the inside of your door or in your manual to find the right psi, unlsee you are really heavy, like with 500 extra punds in your car.
SHEEEIT!^Looks like you said it man!

dalaw

dont your wheels get really heavy which results in a lot of unsprung weight if you pump yours tires up really high?

EM2 Bluez

Guys Guys Guys now let it be known running 50psi is not impossible or 60 at that fact. But if you are running that high of a PSI think of how much higher it will get when it warms up. I've been running 28 PSI's and when that thing heats up it went up to 32. I've pumped tires up to 80 PSI's before and nothing. But ive pumped a tire to 40PSI and blew up on my finger and nails went bye bye. IF you think max sidewall is 51 and you run 50? think of wieght adding to it and heat. Your tires will just pop off your rim. If you guys think its right go ahead ill stick with 28 PSI

philmcneal

i've driven a car for 10 km's in the city with lots of stop and go and right after checking the psi again it still remained at the same number. Yes I was using a digital gauge, and no I do not drive like you guys in an agressive manner. ANd of course i had my whole family on aboard my car, they never complained about the ride. Niether do my friends and I made sure the pressure was right one more time before going to pick them up. Before you make accussations try to learn about the driver first, if you haven't notice I do not drive like any of you unless you get the same mileage as I do. So my tires go through much different conditions than what normal people drive.

All I'm saying is as for aiming for high gas mileage, I'm at 60 psi for awhile and I doubt I notice a difference, although what I do notice is temperature really sends all the tires out of psi very easily. As well I think having my car parked on an incline might affect pressure from each tire somehow? OH and cornering at high speeds is pretty sweet I can feel I can take a turn at a higher speed and not experience any slight of tires burning or understeer (I corner to conserve momentum not to break records).

tbaleno

Yes, tires heat up and the psi goes up. However, tires heat up mostly from sidewall flex of which there is much less if any at higher psi. Many manufaturers specificaly recomend against LOW PSI. Having talked to a tire engineer and asked questions about the saftey of increasing PSI in my tires he was insistant that low PSI by 5lbs is much more dangerous that 20PSI over.

I saw someone post above that high psi increases the likelyhood of hydroplaining. This is false. The reason being is that yes, the tread has less surface area. However, this has the opposite effect in watter. The tire more easily gets through the water and on to the road. Think of a knife plunging into water vs your hand.

You will notice that on tires the Max sidewall preasure is pretty much the same from brand to brand. There are only a few pressures. Basicly tires are tested to PSIs >100lbs so there is no need to worry about them bursting with PSIs even double the max rating. (Note, I wouldn't go above 60psi because there is no point)

I don't care if people have an issue with running higher PSI. Its there choice, but get the facts straight.

Cons:
Longer stoping times in snow.
Harder on suspension
Louder ride.

Pros:
Can give better handling
Better Gas Mileage
Longer life of the tire (Less flexing means tread lasts longer) (Some people think it will wear unevenly but this is only true for non steel belted radials as the steel belts help the tire retain shape).
Less Hydroplaining
Load handling goes up.

The reason most manufacturers use the PSI they do is 1) comfort, 2) road noise, 3) load handling.

They want the minimum PSI required to hold the load of the car because it will give the best comfort and road noise. Ford got in big trouble with this when they underinflated the firestones and started pointing the finger at the tires.


Reference
http://www.tiresafety.com/


I hope people look for facts instead of just taking what they "feel" is correct without actualy looking it up. In fact don't take what I say as fact either. I ask everyone reading this to research on other sites without a bias. Check out the tire manufacturers and look for where they say "don't over inflate your tires" I don't think you will find nearly as many (if any) references as "make sure your tires are properly inflated" (note the word inflated is not the same as deflated).

Anyway. Do what you want, use common sense, if you don't feel comfortable with higer PSI don't run it. But don't spread lies either.

I don't see what the big deal is. People on this site change suspension add after market mods on, and do countless things to the engine, and *gasp* speed, all can be far more dangerous than overinflating their tires. The key point is know what you are doing and you will be safe.

drive_fast_dail

Its pretty insignificant. Going off of a 30 psi stock to 50 psi and just using the ideal gas law and assuming about 1.5 cubic feet of inside the tire it comes out to be is 0.342 lbs at 30 psi and 0.495 lbs at 50 psi. Thats only a 2.45 oz increase, less than a bag of chips. Pretty small compared the total mass.

As for hydroplaning and less control, the main concern IS NOT the size of the contact patch, but the change in the shape. The size is the same along the wheel width but you loose it along your cars length. This is going to make your tires less resistant going sideways. This should not make a difference hydroplaning unless you are a terrible driver and managed to get your car sideways. It will make a difference in snow, since cars often slide sideways to being with. Better all season tread patterns make this change less significant.

Also someone said something about more likely to burst on pot holes. Thats really ridiculous, so long as you arent breaking the max rated pressure there shouldnt be a problem. The tires were tested at that max rated pressure and they will still be very strong at it. Sure lower pressure might prevent it, but the kind of impact that it would take to burst a tire at max psi, would probably just smash the rims at 30 psi. Which brings up another good point, if you run lower profile, expecially 17" and bigger, you probably should run high psi just to protect the rim from getting bent on a hard impact.

jackburton

iTrader: (1)

"Tires: You've already read that you should put an extra 10 to 15 psi in your tires. The reason for this is to keep your tires from rolling under during hard cornering. But how much is too much? Put chalk on the edges of your tire, in three places around the diameter, and you can see how far over the tire was going during your runs. Bleed out a little if the chalk is still showing on the tread, or add a little more if the chalk has been worn off down the sidewall. The line of worn chalk to remaining chalk should be right at the corner of the tread and sidewall. Keep notes on how many psi you ran, and where the chalk line was, for your next event.

Remember that as you get better and corner harder, you'll need more air to compensate, so keep using the chalk at every event."
Taken from Solo2 Novice Handbook

I think I am going to up my tire pressure to 40psi.

Graphicdude

Dude you need to check yourself. Your comments are being interpreted as condescending. You are a new member and need to step back and keep your comments to yourself. You act like you are some sort of "Driving God" well we don't care how you drive and what your mileage is from your Hybrid. Do you want a pat on the back becuase of your superior driving skills? Should we all bow down to the master of mileage? Keep your mouth shut for awhile or edit your posts before you submit them.

myinca

iTrader: (1)

isnt this kind of contradictory?(sp) if it retains its shape bc of the steel belts and doesnt wear unevenly, then how does it produce less tread sufrace and reduce hydroplaning?


i realize they may have come off like a d*** thing to say im just looking for clarification

jackburton

iTrader: (1)

Maybe if you are sliding sideways?

drive_fast_dail

Steel belts keep it from bulding out, but increases pressure still changes the shape of the contact patch by how much it flatens. The biggest advantage on the higher pressure in relation to hydroplanning is wearing the tires properly.
Just today, its just been drizzling here in columbus, my friend who runs the stock 30 psi on his corrolla hyrdoplaned in a bend and curbed a wheel. He said he wasnt even going fast, but wanna know why?
His tread depth is fine in the middle, but his tires are worn to no tread on the edges in the front. Of course he should have been more responsible and seen this and rotated/got new tires. Theres only 10-15k (i dont know exactly) on the tires which are meant for a lot more. That just goes to show the consequences of uneven tire wear that could easily be fixed by increasing pressure.

01HonderCivic

iTrader: (7)

Well put. +1

I don't care who you are or what you drive on the street, putting higher pressure then the max the tire is rated for is dangerous. I worked at a tire shop, I saw idiots who would just stick a hose to their car tires and inflate them until the sidewalls were straight, which they interperted as being "Fully inflated". When in reality they were running around 70 pounds. And I've seen these tires after they blow. Unsafe for any reason

psyshack

Ive ran near to or max sidewall psi in my tires for 25 years or so. Never a problem. I always get 40k to 60k miles out of a set of tires.

06 Civic EX sedan 44psi front, 42 psi rear, 11k miles
05 Accord EX sedan 44 psi front, 44 psi rear, 26k miles
00 Ranger XLT supercab 36 psi front, 36 psi rear, 130k miles. Just went on its third set of tires 15k miles ago.

No matter what psi you choose to run. Keep up with it. Rotate the tires and keep it aligned.

philmcneal

i'll let you know if i experienced a blowout with 61 front and 59 rear for tires only designed for 51 max sidewall.

Needless to say I'm still on my first set of tires, but these tires has gone a long way and now its almost approaching the 50000km mark with green tread in the middle and losing traction for the outside edge although I blame that for my early driving years when I was more like "you guys".

My my a lot of haters for the non believers! I guess you guys just don't believe in the mileage one can possibly get with high tire pressure which is why I upped them in the first place.

Just remember I don't drive like any of you guys at all. My requirements are much different than yours.

Graphicdude

Dude, there you go again. The arrogant, demeaning mannerisms. WTF??? Who the hell are you and don't you learn? Are you seriously mentally disabled or something. Have you not read the past posts and read YOUR posts? Do you not see what everyone else sees here?

It has nothing to do with the "haters for the non believers!" It is your tone of voice. THink for a minute. God your a tool!!

[quote]"Just remember I don't drive like any of you guys at all. My requirements are much different than yours."[quote]

gearbox

iTrader: (95)

i hate when the shop "sets" the tire pressure and when i check the next few days its 38, 35, 32, 39, instead of all 32. when will they learn its only accurate when COLD. this was the best shop in town too btw.

shroomster

geez you jsut don't get it. like gearbox said, check p.s.i when cold. if you're doing the p.s.i at 61,59, you're going to have an end result much higher than that, due to increased air pressure/temps.

also I know the tires can handle higher p.s.i than stated on the sidewall, as I have pumped some 205/50r16's up to about 80-100 p.s.i. to get them on a rim (I know it was bad but hell we didn't have any of the proper tools at the time). would I do it anymore? no, because you are dmaaging the internals of the tire, pressure is called presure for a reason, it's exerting force on everything around it, the more force the more variables come into play like damage and explosion and failure of certain components. please just stop with the 'insightfulness' and get the facts straight. stop posting like you know it all, when in reality you don't have a lcue.

gearbox

iTrader: (95)

i wanna know what kind of mileage you're getting with your insanely high pressure. because i get 42 mpg on 30 psi tires like it says on the car: DO NOT inflate tires over 30psi except when carrying heavy loads.

Zzyzx

Actually what I find completly silly is how philmcneal has taken this One lone site and quoted them as "fact". when EVERY other site from tire mfg's to .Gov have basically said the exact opposite.

jackburton

iTrader: (1)

I would suggest trying like 40psi or 45psi. I would also suggest using some chalk if you really wanna know how your tires are wearing. If they are wearing un even adjust. I am going to try this in the very near future.
Gearbox, I think you should try it out to see if running a little higher will increase mpg, cause I know that you are pretty precise. I can never take the time to get accurate MPG.

^Needless to say I am smug because I love the smell of my own farts , and I am a GOD or King rather because I am personally saving the planet driving around in my mouse mobile like a mad deush bag. That is basically what I am getting from you. I can see you now saving momentum bobbing your head to peter gabrial on your way to the "tool box". I do not drive like "them" either, god forbid that I do not live up to my special "requirements" either. You know I think I may just start pumping up to 60psi, dye my hair purple, take a bubble bath, and call it a day...**** it..might as well take the chicken **** way out right now and punch my own ticket...I believe now...you happy

philmcneal

but its true sadly ^ just look are what you guys are posting compared to mine.

Everything I've said its the truth, if you haven't realize I"m just saying high mpg is very possible on our cars.

Here are stats for the non-believers all data thanks to scangauge and this is done after setting my tires for 61 front and 59 rear.

you don't realize your driving style is inefficent until you are told so. Its the truth sadly.

For my tires in the the middle the tread depth is green while on the outside its near yellow.

OVerall tank is sitting at 42.7 mpg i think, then again the scangauge can be a wacky fellow! I'm still waiting for my gas to run out to do manual calcuations.

Guys just trust me, 7th gen civics are hypermiling tools to boot! Tire pressure is only a very minor fraction of what you must do to achieve high mileage.

Then again judging from the expressions of many of the posts, people still don't care about mileage. that's okay guys i've been here before. Your not the only ones giving me a hard time about what I do trust me, bigger fish has got me worse. You guys are the cream of the crops when it comes to "flames".

check out this thread if you want to see me in a bloodbath http://www.cartalkcanada.com/forum/i...c,45824.0.html

although i have a buldge on my left tires, i'll post a pic later when i'm not lazy. maybe some truth to high tire pressure?

if you don't try? how are you ever going to find out? word of mouth never solves anything these days.

because there aren't any other sites that aim for what we are doing. When we try to do it at other sites we get aha! FLAMED

one more edit

that's a good start, remember i upped the ante slowly too from 30 to 35 to 40 ect but there was a a thread showing the difference mpg at different pressures and there were off by 2 or so mpg so not much at all however

the very beggining very very very beggining to WHY i go for high pressure is that so i can ROLL for a long time without any assistance from the engine. Remember that!

When these tires are finished, i can't wait to start fresh from 60 psi and see how that fares with me. These tires I got now have too long of a history to begin changing them from what they were before... drift city!

Although for now, i'll stick with these pressures in the summer (temps are reaching 20 degrees C now over here in british columbia) and let you guys know how I'm doing If I get a blowout don't worry you guys will be the first to know promise.

After all it ain't the truth until you got proof, just give me time and my civic can be restored from its "scars". Until then I hope I at least revealed some truth even if it ain't proven yet, but at least I have told people that, "hey its very possible just don't doubt what your car can do just yet."

After all not all peformance is about speed, am I right? Or is it? :P

gearbox

iTrader: (95)

well the shop decided to put mine all upto 40 psi for some reason, but it was way too rough of a ride. sounded like the car was breaking over every bump. put back to around 31 and much better.

and to the poster, you're taking gas mileage every 5 miles and you think its accurate? give me a break. This discussion is over.

Graphicdude

By driving like a grandma with a load of eggs in the back, aren't you worried about carbon build up in your engine?

gearbox

iTrader: (95)

i sure would be. ^ thats just bad driving practice.

jackburton

iTrader: (1)

Yeah common sense your dont drive fast you get better gas mileage. You just gotta ride it out in 5th gear and use cruise control a lot. I only do it like half the time the other half I am reving the **** out of my car.

philmcneal

those are segments, if I were to drive those segments over and over again and calculate my average then I would get a number. If I'm consistant of keeping that segment into the high 50's then my mpg would be around 50 yes no?

there are times I have to speed up (drivers behind me ;(), and I rip it up before an oil change. (redline that is)

nah if you ride with me, you wouldn't even notice what I'm doing, in fact you can enjoy the scenery more and wouldn't feel any surges or jerks to my driving I try to be smooth even with my high pressure, jackrabbit go and stops will be a rough ride like gearbox said.

he's right about 5th gear (1100 rpms climbing a mild hill anyone? Nope not lugging my engine load is only around 30 percent! On the highway as high as 2800 rpms 100km/h my engine load is at 50 percent!)

I like to punch it sometimes, but usually just 2nd gear.

1st gear helps me propel the car from dead stop
2nd gear is a punching gear usually (climb revs into power band)
3rd gear is low speed cruise
4th gear is medium speed cruise
5th gear is the gears of them all! the gas savers! The magic gear that can net you over 80 mpg if you baby it properly. Any harder in the throttle and you might as well be in 4th unless you enjoy being in lug city.

Cruise control is nice, but its a shame my car doesn't have it. So on the highway I baby my throttle for high mpg (80,60,40) as it drops I rise my foot and then repeat the game again. Right lane of course

I don't drive jerky, I drive like an automatic transmission smooth and silky. C'mon I'm trying to keep this car, not trash it to the ground :P

01HonderCivic

iTrader: (7)

Now I know for sure that you're full of ****.

philmcneal

Prove me wrong? Which quotes throw you off I'll be happy to offer you my reasoning. I still haven't got one problem from this car, not one, not nada, not zilitch. Maybe I'm lucky to getting the 2nd last year of the 7th gen who knows, but my scangauge doesn't lie man. Also to add if my engine was lugging with very little throttle why doesn' it "cry" when it does as I accidently press too much throttle? 80 mpg is only achieveable if for me

a) the road is somewhat flat or sloping down (sometimes even your eyes can't tell if that road will glide you or not. There are times when coasting will tell you the true story.)

b) I'm bleeding of my speed, so for example 60km/, 59km/h, 58/km but during that decel I'm getting more than 80 mpg for sure, its just my speed is dropping slowly. I usually let the speed drop to 40 or 45 (depending on who's behind me) and then rev match into 4th to get my speed up again and then repeat when I don't feel like FASing (forced auto stop).

Do you even know how i shift? I try not to let the syncros do any work.

that's how i shift, although 3000 is kinda high for me but i'm still experimenting. There's a quote I thought was interesting too

zadscmc

I run my Bridgestone B321s at 44 psi, the sidewall maximum.

The car handles great, I have excellent control in wet weather, and my car is getting 15 percent better mpg.

However, I would hestiate to go much more than the sidewall max.