Tire Education.... Air pressure, runflat, ect....
cadillac ats forums cadillac ats forums
CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Page 1 of 2 1 2 LastLast
Results 1 to 15 of 20
Like Tree4Likes
Cadillac ATS Technical Discussion Forum Discussion, Tire Education.... Air pressure, runflat, ect.... in Cadillac ATS Discussion Forums; Hello All, I have to way in on some of the tire comments here and help if I can. Air ...
  1. #1
    nissanite is offline Cadillac Owners Member
    Automobile(s): 2013 ATS Performance
    Join Date
    Apr 2014
    Posts
    16

    Tire Education.... Air pressure, runflat, ect....

    Hello All,
    I have to way in on some of the tire comments here and help if I can.

    Air Pressure- Should be set cold at door placard specs. Here are some tips-
    pressure changes about 1 lb for 10 degrees of change. Example- if I set mine
    early AM at 32ft - 35 rr with an ambient temp 50, in the afternoon at 80 ambient
    they will grow to 35 - 38 by themselves. This is without driving. If you drive for a
    few miles at highway speeds the pressure will grow a few more lbs, maybe 3.
    So that could be close to 38ft 41rr. This will keep the TPMS tale tale from
    illuminating in the morning.

    Runflat - first, more and more Runflat tires are in our future. Think of the evolution
    Of Bias ply to Radial. Cars are being mandated to achieve more fuel economy and a
    trend is shifting to smaller vehicles. Fact - runflat tires have been heavier and stiffer in the past but since around 2010 technologies have been discovered and that
    issue is improving.
    Our ATS sedans have
    been tuned on the Nurburgring by some extremely talented engineers. The stiffer
    sidewalls of run flats may add to the effective spring rate. The slightly heavier tire
    will require a different dampening rate. If you remove the OEM designed tire you
    are changing the suspension as well as the tire.
    Runflat tires will not blowout. If a rapid loss of air occurs the TPMS tale tale will
    illuminate with a warning and the tire should keep the car under control. This is
    very different from traditional tires. You should not be stuck at the side of a road
    waiting on help that could be longer to arrive than you wish.

    Touring vs Performance tires - performance tires ride firmer, require less steering
    input, handle and corner better. To do this they may sacrifice ride and wear life.
    touring tires ride smoother, last longer and may be quieter but usually sacrifices
    some grip and steering crispness.

    I am a UHP Education Specialist for Bridgestone Americas. I am not an engineer but
    attempt to clear tire rumors where I can.
    vwvr6tom likes this.

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    donavo is offline Cadillac Owners Connoisseur
    Automobile(s): ATS RWD 2.0T MANUAL
    Join Date
    Feb 2011
    Location
    Los Angeles, California, Unite
    Age
    24
    Posts
    1,220

    Re: Tire Education.... Air pressure, runflat, ect....

    so if ur car comes with runflas, changing the whole wheel to a lighter wheel in general is a bad thing?

  4. #3
    nissanite is offline Cadillac Owners Member
    Automobile(s): 2013 ATS Performance
    Join Date
    Apr 2014
    Posts
    16

    Re: Tire Education.... Air pressure, runflat, ect....

    Let's not say a bad thing. The car has been tuned for years with the tire that was chosen. Normally the tire has been engineered for at least 2 years before the car is launched.
    Lighter is better but it would be better in the tuning phase.

    Run flats actually may handle better due to the slightly firmer side wall. Bridgestone is launching a tire nation wide this month that is very near ride and handling to a premium touring tire. Millions of dollars and a tremendous amount of research goes into these tires. They get better every year. Not you grandads run flats anymore.
    exbagboy and vwvr6tom like this.

  5. #4
    Ragtop 99's Avatar
    Ragtop 99 is online now Cadillac Owners Enthusiast
    Automobile(s): ATS 2.0T RWD
    Join Date
    Oct 2013
    Location
    Bethesda MD
    Posts
    887

    Re: Tire Education.... Air pressure, runflat, ect....

    Quote Originally Posted by nissanite View Post
    Run flats actually may handle better due to the slightly firmer side wall.
    That seems intuitive that the hard sidewall might help, but it seems like stickier tread compounds came on the highest performing regular tires that weren't on the highest performing runflats. Maybe that's changing too? Have you seen anyone test their runflat and non-runflat version back to back on the same car and generate hard data showing the runflat doing better than the regular tire?

  6. #5
    100%_N1's Avatar
    100%_N1 is offline Cadillac Owners Fanatic
    Automobile(s): 2013 ATS 2.0T RWD, Luxury
    Join Date
    Oct 2013
    Location
    Charlotte, NC
    Posts
    189
    Quote Originally Posted by nissanite
    Air Pressure- Should be set cold at door placard specs. Here are some tips- pressure changes about 1 lb for 10 degrees of change.
    Hello Nissanite, thanks for sharing your knowledge. I've got a question for you. My ATS is a RWD and has a placarded recommended PSI of 35 front 40 rear. As you know, years of research and development has gone into this, but if I set the tire pressure at cold, the operating psi is obviously much higher. Is this taken into account? For example, I set my pressure to 34 front and 38 rear cold. It takes a few minutes after driving for them to be 36, 41 respectively as planned. However, sometimes when I go on trips during warm weather it can show 40 and 46. This makes me nervous and I typically stop and reduce the pressure and will just fill them back up to 34-38 cold later. What are your thoughts? Thanks

  7. #6
    sebounet's Avatar
    sebounet is offline Cadillac Owners Member
    Automobile(s): cadillac ATS 3.6 AWD performance
    Join Date
    Nov 2013
    Location
    Montreal, Canada
    Age
    46
    Posts
    78

    Re: Tire Education.... Air pressure, runflat, ect....

    Run flat tires is just a new way for rubber manufacturer to sell more tires...

  8. #7
    pissedoffwookiee's Avatar
    pissedoffwookiee is offline Cadillac Owners Connoisseur
    Automobile(s): 14 ATS Premium 2.0T Phantom Gray, 13 SRX Luxury Carbon Black
    Join Date
    Mar 2013
    Location
    San Diego
    Posts
    1,361

    Re: Tire Education.... Air pressure, runflat, ect....

    Quote Originally Posted by sebounet View Post
    Run flat tires is just a new way for rubber manufacturer to sell more tires...
    i disagree BMW is most notable for early wide use of runflats, this was for many reasons one of which is the need to improve performance both in fuel economy and safety in the context of autobahn use...there are cars that have the mission critical need to run full size spares trucks and utility vehicles are notable but German cars have this need/requirement too (since they don't blow out like regular tires you can more safely come down from autobahn speeds and you don't have to stop immediately for repairs)....runflats serve a lot of these purposes nicely....so from the manufacturers perspective its a win on safety, a win on fuel economy, a win on performance in terms of vehicle dynamics, but a loss on ride quality...so in the eyes of the manufacturers the compromise of 3 wins to one loss was an overall win....lastly how is having run flats selling more tires when manufacturers are selling thousands of cars with one less tire?

    i don't care one way or the other, i buy the car i want and it has what it has
    vwvr6tom likes this.

  9. #8
    jadatis is offline Cadillac Owners Member
    Join Date
    Nov 2013
    Posts
    2

    Re: Tire Education.... Air pressure, runflat, ect....

    Quote Originally Posted by Camorri1 View Post
    Hello Nissanite, thanks for sharing your knowledge. I've got a question for you. My ATS is a RWD and has a placarded recommended PSI of 35 front 40 rear. As you know, years of research and development has gone into this, but if I set the tire pressure at cold, the operating psi is obviously much higher. Is this taken into account? For example, I set my pressure to 34 front and 38 rear cold. It takes a few minutes after driving for them to be 36, 41 respectively as planned. However, sometimes when I go on trips during warm weather it can show 40 and 46. This makes me nervous and I typically stop and reduce the pressure and will just fill them back up to 34-38 cold later. What are your thoughts? Thanks
    Dont worry about the pressure rising that goes with the temperature rising in the tire, and dont blead air when warm. The tire makers calculated that into their advices.
    This warming of the air inside the tire is by driving because the rubber bends and produces heat and pretty normal is that it goes from cold ( inside temp = outside temp) 18dgrC/65dgrF to warm 45dgrC/112dgrF. but by sunshine on the black rubber it can rise higher and when braking the heat of the brakes , transported trough the rims can heaten up the tire inside air to boiling point of water so 100dgr C / 200dgr F.
    With that temperature rising the pressure rises, and I even made spreadsheet for it to play with.
    Even the valves are tested and standardised to can stand the pressure- and temperature-rising and the maximum pressure they give is cold measured so at 18 dgrC/65dgrF inside and outside tire temperature.

    I also am not a tire-specialist, but got hold of the official formula in Europe to calculate pressure for a sertain load, and gathered a lot of info in the years on internet and asking people of tire-maker and others who seemed to have knowledge about it. Some names Barry Smith ( Capri racer) and Mr J.C.Daws and American IR who's article I found about a new alternative way of calculating tire-pressure and comparison with the different used formula's in America and Europe.
    Live in Holland ( Europe).
    Placed a lot of spreadsheets and stuff on my one-drive (former Skydrive) that belongs to my hotmail adress with same username as in this forum ( so combine yourselfes, spamm machines cant this way). Here the link to the public map with about 75% about tire/tyre-pressure.
    https://onedrive.live.com/?cid=a526e...E092E6DC%21128

  10. #9
    sebounet's Avatar
    sebounet is offline Cadillac Owners Member
    Automobile(s): cadillac ATS 3.6 AWD performance
    Join Date
    Nov 2013
    Location
    Montreal, Canada
    Age
    46
    Posts
    78

    Re: Tire Education.... Air pressure, runflat, ect....

    Quote Originally Posted by pissedoffwookiee View Post
    i disagree BMW is most notable for early wide use of runflats, this was for many reasons one of which is the need to improve performance both in fuel economy and safety in the context of autobahn use...there are cars that have the mission critical need to run full size spares trucks and utility vehicles are notable but German cars have this need/requirement too (since they don't blow out like regular tires you can more safely come down from autobahn speeds and you don't have to stop immediately for repairs)....runflats serve a lot of these purposes nicely....so from the manufacturers perspective its a win on safety, a win on fuel economy, a win on performance in terms of vehicle dynamics, but a loss on ride quality...so in the eyes of the manufacturers the compromise of 3 wins to one loss was an overall win....lastly how is having run flats selling more tires when manufacturers are selling thousands of cars with one less tire?

    i don't care one way or the other, i buy the car i want and it has what it has
    Because those runflat tires can't be repaired mostly. I had some flat before, i stop the car, use the spare tires, and bring my tire to a tire repair shop. One of my tire had 3 small repairs. With run flat tires i would have need to buy 3 new tires each times. That's why i say , they are selling more tires by this way. And i push a bit my thinking, because most people are not satisfied with OEM run flat tires, they buy an other set of non run flat tires, even on a brand new car

  11. #10
    nissanite is offline Cadillac Owners Member
    Automobile(s): 2013 ATS Performance
    Join Date
    Apr 2014
    Posts
    16

    Re: Tire Education.... Air pressure, runflat, ect....

    Some run flats can be repair just like a normal tire. If you drive on a conventional tire it will be ruined also. The runflat is not made to save money on its own. Will save space and help fuel economy. By 2025 car manufacturers must average 54.5 mpg on the fleet. Run flats are a way to help archive this.

    Jadatis - correct on the air pressure response, thank you. This is very misunderstood and rarely done correctly.

    Ragtop 99- I have not seen tests back to back but have many testimonials. The wear rate is determined by the tread compound. It does not relate to the runflat sidewall. A performance tire will wear faster, runflat or not.

  12. #11
    ChevyRules is offline Cadillac Owners Member
    Automobile(s): 2014 Cadillac ATS Premium 3.6 AWD
    Join Date
    Mar 2014
    Posts
    81

    Re: Tire Education.... Air pressure, runflat, ect....

    Quote Originally Posted by sebounet View Post
    Because those runflat tires can't be repaired mostly. I had some flat before, i stop the car, use the spare tires, and bring my tire to a tire repair shop. One of my tire had 3 small repairs. With run flat tires i would have need to buy 3 new tires each times. That's why i say , they are selling more tires by this way. And i push a bit my thinking, because most people are not satisfied with OEM run flat tires, they buy an other set of non run flat tires, even on a brand new car
    Yeah as nissanite said, some run flats can be repaired. I know my dads old E90 335xi had a puncture in its tire and it was repaired.

  13. #12
    Ragtop 99's Avatar
    Ragtop 99 is online now Cadillac Owners Enthusiast
    Automobile(s): ATS 2.0T RWD
    Join Date
    Oct 2013
    Location
    Bethesda MD
    Posts
    887

    Re: Tire Education.... Air pressure, runflat, ect....

    Quote Originally Posted by nissanite View Post
    Ragtop 99- I have not seen tests back to back but have many testimonials. The wear rate is determined by the tread compound. It does not relate to the runflat sidewall. A performance tire will wear faster, runflat or not.
    I guess I hear the testimonials going the other way. I know that wear rate is related to compound, I kept nitto DR's on my camaro for street use and they were done at 8k miles. My point is that I haven't seen a runflat with a sticky compound. Without a sticky compound, there is a limit to an advantage created by sidewall stiffness. Maybe the lack of an OEM sticky runflat is a function of the car companies not wanting the tires to wear out in 20k miles, whereas someone buying a high performance aftermarket tire can make that decision.

  14. #13
    Hoosier Daddy's Avatar
    Hoosier Daddy is offline Moderator
    Automobile(s): 2013 ATS Performance 2.0T M6
    Join Date
    Feb 2013
    Location
    Winchestertonfieldville, AZ
    Age
    65
    Posts
    3,919

    Re: Tire Education.... Air pressure, runflat, ect....

    Past Z06s came from the factory with extreme performance summer run flats: http://www.tirerack.com/tires/tires....3A+2+RunOnFlat

    So they do exist. Don't know if the reasons there aren't a lot of choices is because they suck or because enough people won't buy them for another real or perceived reason.

  15. #14
    pissedoffwookiee's Avatar
    pissedoffwookiee is offline Cadillac Owners Connoisseur
    Automobile(s): 14 ATS Premium 2.0T Phantom Gray, 13 SRX Luxury Carbon Black
    Join Date
    Mar 2013
    Location
    San Diego
    Posts
    1,361

    Re: Tire Education.... Air pressure, runflat, ect....

    Quote Originally Posted by sebounet View Post
    Because those runflat tires can't be repaired mostly. I had some flat before, i stop the car, use the spare tires, and bring my tire to a tire repair shop. One of my tire had 3 small repairs. With run flat tires i would have need to buy 3 new tires each times. That's why i say , they are selling more tires by this way. And i push a bit my thinking, because most people are not satisfied with OEM run flat tires, they buy an other set of non run flat tires, even on a brand new car
    actually more and more regular tires can't or won't be repaired either...a bunch of dealerships in my area will not repair tires anymore for liability reasons they replace only and refer you to tire shops like discount tire for repairs and when you go to them they have increasingly strict guidlines for whats repairable......so it seems the repair advantage of non run flats is eroding

  16. #15
    redsoxski's Avatar
    redsoxski is offline Cadillac Owners Fanatic
    Automobile(s): 2013 Performance ATS 3.6 white diamond tricoat
    Join Date
    Sep 2013
    Location
    Roswell ga
    Posts
    103
    Quote Originally Posted by nissanite
    Some run flats can be repair just like a normal tire. If you drive on a conventional tire it will be ruined also. The runflat is not made to save money on its own. Will save space and help fuel economy. By 2025 car manufacturers must average 54.5 mpg on the fleet. Run flats are a way to help archive this. Jadatis - correct on the air pressure response, thank you. This is very misunderstood and rarely done correctly. Ragtop 99- I have not seen tests back to back but have many testimonials. The wear rate is determined by the tread compound. It does not relate to the runflat sidewall. A performance tire will wear faster, runflat or not.
    I recently ran over a nail with my run flats and my dealer patched it with no problems.... He said nothing could have been done if sidewall was compromised, but since nail was in middle of tire, all OK. Thanks you Classic Cadillac in ATL for saving me money.

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting