I just got my new 16" Konig Heliums with Kumho AST 205/45/16 series tires, wondering what tire pressure I should run on them, currently its around 45psi, kinda high???

 

45psi cold is super too high.

run 34-35 range cold. measure in the morning before the sun's out or while
your car's in the garage.

 

Tire pressure is a hotly debated topic. Many in the Eco forum would advise to run the max pressure stated on the sidewall of the tire.

Some would say never run more than 35psi, while others would say that running 55psi is perfectly fine.

I run 45psi myself in my tires, which are Hankook Ventus HRII 205/50/R15 mounted on Konig Next 15"x7" wheels.

Do some more searching here on the forums before making your decision.

 

Check out this thread: https://www.fitfreak.net/forums/eco-...ficer-com.html

And this article found in that thread: Driving Under Pressure: Editorial & Features at Officer.com

 

the only 55psi tires i run are donuts.


you are a moderator. you ever hear about safety? why promote this?

too high psi is not only uncomfortable, it is dangerous. tires are not
programmed to work at such high psi, especially not in the summer's
excessive heat. your tires could explode from not only heat expansion,
but from impact. your tires will bulge in the center tread as it rotates
faster picking up centripetal force making less contact patch loosing
traction.

the shit tire manufacturers have to take from these irresponsible
users.


45psi has margin from exploding from heat expansion, but you are nearing
the limit of the tire's designed psi. Your tires can reach 50psi+ after it
building up heat from normal driving on hot pavement. max psi does
not mean max as in max you can use.

max means max as a reference before it deforms enough that it may
structurally fail.

 

Where in my post did I ever promote anyone to run 55psi? I merely stated what some people say. I did not in any shape, form or fashion state my opinion on what everyone should run.

I then stated what I run on my car in my city in my climate in my driving conditions. 45psi worth of nitrogen in my situation is not on the raged edge of deformation and explosion.

I then recommended the OP do some research to see what he feels is best for him.

You really should not jump on people for imagined offenses.

 

"Many in the Eco forum would advise to run the max pressure stated on the sidewall of the tire."

bandwagon promotion is how i took it. if MANY folks use max pressure it
must be ok!

btw, wat's with the bold text?

 

a products MAX rating is always a percentage lower than the actual "tested" MAX.

for example, in the live sound world, for speakers that are raised up or "flown" their mounts have must meet a 7:1 or sometimes 10:1 weight ratio. That means that the mount must hold 7 to 10 times the weight of the speakers for safety reasons, or course.

Do you think tire manufacturers would really print their absolute MAX pressure on the sidewall? If that were true, they'd have an assload of lawsuits from the people who overinflate or don't monitor their tire pressure.

Auto makers put a very conservative number on the door jamb to meet a balance of safety, mileage, wear, and comfort. other than that, you can pretty much put your PSI at anywhere near the MAX and be fine. Sure, you may feel more bumps on the road, but you're not gonna fly off the road or anything. Just pay attention to your load capacity too when you're filling your tires.

You know, the conservatives and "speculators" are the main reason why crude is at 139 a barrel. Think about it. If peeps would stop "speculating", maybe we'd really begin moving forward.


-emil

 

no kidding. you need to put into consideration real world conditions.

why dont you and your gf/wife/husband family fill your tires at 55psi
cold and field test for us in 100F+ temps? (no dont do that!)

 

or course, "could" and "should" mean two different things.

it's like, a casual "druggie" who will buy random pills from a guy at a party, but freaks out when he finds that the bottle of aspirin he bought from a reputable store was "tampered" with

-or-

like lowering a car when the manufacturer, as well as the cops, say that "it's not recommended"

but hey, you do these things because you're using your own judgement.

The 32 psi recommendation from the manufacturer is not a hard-and-fast rule.
check your tires cold (meaning after you car has been sitting away from direct sunlight for at least a 3 hours) and put them above 32 but below 51. test a few different PSI's in between and find what works for what you're after.

 

car manufacturers go primarily for comfort. for a car of this weight
34-35psi is a good starting point with consideration to performance
with acceptable levels of comfort and to maintain the load rating.

on a hot summer day i would use 33psi compensating for the
expected heat expansion. at operational temp, the tires are
going to be in the 38+psi range.

if you pump your tires to 35psi on a 85F day it can go as high
as 40+psi where as if you pump 35psi on a 30F day, your max
temp could only reach 37-38psi.

as you can see, in real world conditions there are many variations.
not only temperature but impacts from road conditions, your
vehicle load weight (with/without passengers), the weather your
tires have endured resulting in variable amounts of wear. the way
you drive your car, etc.

your comment of 32 to 51psi as operational range is just too wide.
tires do not necessarily work better when they are over inflated in
most cases.

just use the manufacturer's recommended rating for comfort and
start 34-35psi for performance oriented with comfort with compensation
to real world conditions.

ive explained enough.

 

OK EVERYBODY STOP!!!


Thanks! This is not an ECO question, this is not an Autocross question. Correct?

The recommended pressure it set by the manufacturer at 32PSI IRREGARDLESS of the type of tire. If the question is what should you be running, the answer is 32psi (cold). If your questions starts involving running on courses, getting better mileage, ect.... then you can review the rest of the advice. Refer to both your owners manual and the tire pressure information marked on the inside sill of your driver door.

Again, anything else is purely for eco and autocross reasons ONLY! Now, there is a lot of good information here depending on what you are looking to do with your car.

Thanks for your time,
Please resume

 

yeah, i got a little nutty w/ my response. sorry about that, guys. hey kenchan, nothin' like a good debate, huh?

 

thanx guys for all the info, seems like somewhere between 32-35psi should work great for me, especially in WA cause it rarely gets warmer then 75...

 

hey bacalia - im a believer in real world conditions and experimentation. we're cool.

debates are always good.

it's good to read and question and think about it and decide for yourself
wat you want to do.

 

I was going to recommend 32psi for all four tires, but it looks like you already figured out what you want to do.

 

You didn't mention your wheel rim width which is important. For example a 6" wide rim will need less pressure than a 7" width. The difference may be only 5 psi. And more front to back.
I would vote for the 30 to 35 psi range to start and do a few 360's to measure the tire rollover (using white shoe polish stripes at 90 degree intervals on the outside tread corner) Theoretically you want the shoe polish worn off just at the edge of the tread width. Your selection of radius for the 360's is important too. The radius should be about equal to that of your tightest turn anticipated.That way you'll be using all the tire.
The reason for raising the pressure on wider rims is to cause the tire carcass to flatten the tread against the road. As the rim width increases lower pressures let the tire tread 'bow' upward in the middle reducing the tire patch even though you may not see it. Thats where measuring tire temps across the tread are valuable. And of course you expect to get different readings at each end of the Fit - and often across the axle. When you weigh your Fit you will find that the weights across the axle aren't the same.
BTW keep all this stuff in a nice notebook for future reference. It will became as good as the best A/X tires you use.
Competing in an autocross is technically demanding, just not quite as much as NASCAR or IRL but its how to get started.
And it must be understood that the manufacturer's recommended pressures is for street driving, not competitive driving. You may end up after your shoe polish testing running 40 to 45 psi to keep from rolling the sidewalls over. In the 'old' days Michelin and Pirelli both recommended raising tire pressures by 5 to 10 psi over recommended for 'high speed driving'.
cheers and good luck.

 

Aw shucks! You mean all those Firehawk races (up to 6 hours and 3 drivers) with tires at 45 psi cold (and 55 hot)wasn't necessary? Gee when we ran lower pressures lap times suffered. There were broken wheels from improperly torqued lugnuts but tire blowouts were always from 'debris'.
And if you go to those July 4th races at places like Holtvillre or Savannah you'll find out what happenes when temperatures exceed 100F and the track 130F.
Tires aren't that fragile; they are pretty tough. The lower pressures recommended are so grandma won't complain about taking the wagon.When you drive at limits fairly stiff tires are necessary. That only happens with higher psi.

 

im quoting your post since you keep editing them. this is a
good example of the generalization you want to stay out of.

a few hundred tires on controlled environments were okay, ALL tires
made in the world and used by a regular joe and jane must be okay to
run excessively high pressures on street!

NO. absolutely no.

anyway, ive explained enough. the enduser can make his/her own
decisions reading my posts and others. im over and out for this thread.

 

Sorry, I have to respond as an engineer who spent a few years in the tire business.The ultimate burst pressure of a non-defective tire is measured in hundreds of psi.
You run pressures of 25 to 40 psi for comfort and performance. The higher speeds and higher vloads need higher pressures. Those who run recommended unloaded pressures at huigh speed and or high loads flirt with disaster. Just ask Ford about the SUV problem.
But all tires have a max pressure rating and that is a goosd starting point for HD service.