New Tires - Q on Pressure:
#2854911
12/03/20 07:37 PM
12/03/20 07:37 PM
|
Joined: Jan 2003
Posts: 8,451 Highland, MI.
Sunroofcuda
OP
master
|
OP
master
Joined: Jan 2003
Posts: 8,451
Highland, MI.
|
Put a new set of tires on my 2016 Chrysler 300 yesterday. I asked the installer what pressure he pumped them up to, & he said 38 pounds. Looking on the tires, they say max PSI is 51 pounds. The sticker on the door says to inflate TP to 30 pounds. On the drive home yesterday, tires felt really pumped-up & hard. Today, I checked the TP on all 4 & 3 of them were 34 pounds, the LR was 39 pounds. I always thought the most common TP on a passenger car was 32 pounds. Anyway, I set all 4 tires this morning at 34 & it still feels too hard. Do I go with Chrysler's recommended pressure of 30 PSI?
No Man With A Good Car Needs To Be Justified
|
|
|
Re: New Tires - Q on Pressure:
[Re: Sunroofcuda]
#2854954
12/03/20 09:04 PM
12/03/20 09:04 PM
|
Joined: Jan 2003
Posts: 12,801 Benton, IL.
DaveRS23
Master of nothing...
|
Master of nothing...
Joined: Jan 2003
Posts: 12,801
Benton, IL.
|
If you run 30lbs, they will wear the shoulders. And how often do you want to check the inflation? We see a lot of tires. Most are worn excessively on the shoulders. A few are worn evenly. But I can't remember the last time I saw tires worn in the middle. The lesson here is to keep at least a little more than the door sticker recommends. How much is your call. But with cold weather here, and with most of us not being religious about monitoring our tire pressure, it makes even more sense to keep a little extra pressure in them. On a rear wheel drive like yours, my rule of thumb is 5lbs over the door sticker. For front wheel drives, I still use at least 5lbs extra in the fronts, but only keep a couple of extra lbs in the rear, if there are not typically loads in the rear. Just my
Master, again and still
|
|
|
Re: New Tires - Q on Pressure:
[Re: Sunroofcuda]
#2855190
12/04/20 12:16 PM
12/04/20 12:16 PM
|
Joined: Mar 2007
Posts: 3,298 West Coast, USA
jbc426
master
|
master
Joined: Mar 2007
Posts: 3,298
West Coast, USA
|
Using tire pressure as a measure to properly inflate tires is a tool to help target and ensure the correct shape of the tire where it contacts the ground. It is dependent on the tire's load carrying capacity and the weight you are actually loading onto the specific tire.
Most of us rarely load a tire to its maximum load carrying capacity, at which point the Max tire pressure is listed on the sidewall. In fact, most of my vehicles only have about half the maximum load weight on them. It's all about getting the tire to have the proper shape where it hits the ground.
I use chalk to help determine the correct tire pressure, record that psi number and use it to check and set that pressure from then on. I simply scrub the chalk across the tread of the tire in a one inch wide band from side to side on the tread, drive the car forward 40 or 50 feet and see where the chalk has been rubbed off, middle, outside edges or evenly. I adjust the tire pressure to get a full even scrub of the chalk off the tread. That is the tire pressure I need for that tire with that load on it. Period.
I generally run 32 up front and 18 in the rears to get them to the correct shape. Other factors such as spirited driving at higher speeds sometimes force me to increase rear tire pressure a couple of pounds to help stiffen the tire flex out back.
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's 1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)
|
|
|
Re: New Tires - Q on Pressure:
[Re: Sunroofcuda]
#2855200
12/04/20 12:53 PM
12/04/20 12:53 PM
|
Joined: Nov 2003
Posts: 10,228 Colleyville
3hundred
I Live Here
|
I Live Here
Joined: Nov 2003
Posts: 10,228
Colleyville
|
Put a new set of tires on my 2016 Chrysler 300 yesterday. I asked the installer what pressure he pumped them up to, & he said 38 pounds. Looking on the tires, they say max PSI is 51 pounds. The sticker on the door says to inflate TP to 30 pounds. On the drive home yesterday, tires felt really pumped-up & hard. Today, I checked the TP on all 4 & 3 of them were 34 pounds, the LR was 39 pounds. I always thought the most common TP on a passenger car was 32 pounds. Anyway, I set all 4 tires this morning at 34 & it still feels too hard. Do I go with Chrysler's recommended pressure of 30 PSI? 30 has been fine in both my newer 300s, P245/45R20. OEM, Firestone Firehawk on the '13, Goodyear supercar on the '16, and aftermarket, Michelin primacy MXM4. Over 100,000 miles logged on two cars. 2ยข
'68 Fury Convertible '69 300 Convertible '15 Durango 5.7 Hemi '16 300 S Hemi
|
|
|
Re: New Tires - Q on Pressure:
[Re: jbc426]
#2855221
12/04/20 01:30 PM
12/04/20 01:30 PM
|
Joined: Oct 2005
Posts: 5,003 WI
Dcuda69
master
|
master
Joined: Oct 2005
Posts: 5,003
WI
|
I use chalk to help determine the correct tire pressure, record that psi number and use it to check and set that pressure from then on. I simply scrub the chalk across the tread of the tire in a one inch wide band from side to side on the tread, drive the car forward 40 or 50 feet and see where the chalk has been rubbed off, middle, outside edges or evenly. I adjust the tire pressure to get a full even scrub of the chalk off the tread. That is the tire pressure I need for that tire with that load on it. Period.
I generally run 32 up front and 18 in the rears to get them to the correct shape. Other factors such as spirited driving at higher speeds sometimes force me to increase rear tire pressure a couple of pounds to help stiffen the tire flex out back.
While that method may work on our old cars it sure won't fly on a 2016. 18 psi will certainly flag the TPMS light(and rightly so) TPMS limits are based off what's published on the door tag.
|
|
|
Re: New Tires - Q on Pressure:
[Re: 3hundred]
#2855229
12/04/20 01:44 PM
12/04/20 01:44 PM
|
Joined: Jan 2003
Posts: 26,470 Rio Linda, CA
John_Kunkel
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 26,470
Rio Linda, CA
|
30 has been fine in both my newer 300s,
Me too, my LX at 30 psi shows no abnormal wear. Go by the door jam sticker if the size is OEM.
The INTERNET, the MISinformation superhighway
|
|
|
Re: New Tires - Q on Pressure:
[Re: John_Kunkel]
#2855263
12/04/20 02:35 PM
12/04/20 02:35 PM
|
Joined: Aug 2005
Posts: 6,033 Salem
Grizzly
Moparts Proctologist
|
Moparts Proctologist
Joined: Aug 2005
Posts: 6,033
Salem
|
It's best to know your vehicle. The condition of ball joints, tie rod ends and proper toe has to be perfect. You'll know this from your old set of tires. Keep track of the pressure you run in the old tires and use it for a guide on the new ones. If you have no records, you will have to experiment with your pressures and keep a close eye on the new ones. It's easy to spot on new tires when the pressure is wrong. I'm a significant amount higher than what the door stickers say on my vehicles. That is generally the case with a high quality tire (Michelin). Junk tires like bridgestone/firestone, and Goodyears I've had to adjust from higher than normal to below normal just to even the basterds out. With Michelins, I set 'em and forget 'em. Rant off. A Mechanical Engineer Friend of mine told me to run more psi in the front. I asked him why and he said because the weight of the engine is in the front. Since taking his advice I run 2psi (half-tons and hot rods, RWD) to 4psi (front wheel drive) more in the front and it's been working perfectly. A Member on here suggested running car hauler tires right to their maximum on the sidewall. I have been doing so, and I want to say "Thank-You": it works! It was the Fellow that used to run a dragster with a red topkick and has the restored Gold '71 Challenger. Challenger1 I think?
Mo' Farts
Moderated by "tbagger".
|
|
|
Re: New Tires - Q on Pressure:
[Re: Grizzly]
#2855296
12/04/20 03:32 PM
12/04/20 03:32 PM
|
Joined: Jul 2008
Posts: 30,632 Florida STAYcation
IcorkSOAK
Financed his waterbed
|
Financed his waterbed
Joined: Jul 2008
Posts: 30,632
Florida STAYcation
|
I beez likein my Scatty at near 40 psi. The ride is a little harsher but it rolls so much easier The rim width is pretty close to the tire width which helps with running higher psi
|
|
|
Re: New Tires - Q on Pressure:
[Re: NITROUSN]
#2855477
12/04/20 10:39 PM
12/04/20 10:39 PM
|
Joined: Jan 2003
Posts: 8,451 Highland, MI.
Sunroofcuda
OP
master
|
OP
master
Joined: Jan 2003
Posts: 8,451
Highland, MI.
|
You may of bought tires not recommended for your application. As said what tires did you buy? Well, they are passenger car touring tires: General Altimax RT 43's. 225/60 R18. What U know bout them? I've had 2 other sets of these on other cars & they are great tires.
No Man With A Good Car Needs To Be Justified
|
|
|
Re: New Tires - Q on Pressure:
[Re: Sunroofcuda]
#2855494
12/04/20 11:11 PM
12/04/20 11:11 PM
|
Joined: Nov 2004
Posts: 25,050 Texas
GoodysGotaCuda
5.7L Hemi, 6spd
|
5.7L Hemi, 6spd
Joined: Nov 2004
Posts: 25,050
Texas
|
You may of bought tires not recommended for your application. As said what tires did you buy? Well, they are passenger car touring tires: General Altimax RT 43's. 225/60 R18. What U know bout them? I've had 2 other sets of these on other cars & they are great tires. Those Generals are rated at 1,794lb/tire at max psi of 51. The OEM tires, Firestone FR710s, are rated at 1,709lb/tire at 44psi. The new tire set is rated for an extra 340lbs at a higher pressure, meaning they have a thicker/stiffer sidewall to accomplish that. I'd suggest starting at what it says on the door and let the tires break in a little before going any lower. OE tire [I believe] https://www.tirerack.com/tires/tire...6&autoModel=300C&autoModClar=RWDYour tire https://www.tirerack.com/tires/tires.jsp?tireMake=General&tireModel=AltiMAX+RT43+%28H-+or+V-Speed+Rated%29&partnum=26HR8AMRT43&vehicleSearch=false&fromCompare1=yes
|
|
|
Re: New Tires - Q on Pressure:
[Re: Dcuda69]
#2855638
12/05/20 11:53 AM
12/05/20 11:53 AM
|
Joined: Mar 2007
Posts: 3,298 West Coast, USA
jbc426
master
|
master
Joined: Mar 2007
Posts: 3,298
West Coast, USA
|
I use chalk to help determine the correct tire pressure, record that psi number and use it to check and set that pressure from then on. I simply scrub the chalk across the tread of the tire in a one inch wide band from side to side on the tread, drive the car forward 40 or 50 feet and see where the chalk has been rubbed off, middle, outside edges or evenly. I adjust the tire pressure to get a full even scrub of the chalk off the tread. That is the tire pressure I need for that tire with that load on it. Period.
I generally run 32 up front and 18 in the rears to get them to the correct shape. Other factors such as spirited driving at higher speeds sometimes force me to increase rear tire pressure a couple of pounds to help stiffen the tire flex out back.
While that method may work on our old cars it sure won't fly on a 2016. 18 psi will certainly flag the TPMS light(and rightly so) TPMS limits are based off what's published on the door tag. Agreed, and I don't know of any 2016 and up cars come with Nitto Drag Radial 265/60-15's on an 8 inch rim. That's the only reason mine get to the correct shape on the ground with such a low pressure. The TPMS on my 3/4 ton truck is always as the factory recommends 60 to 80 psi in the rear tires, which is way to high of a pressure when it's empty. Most trucks I see wear out the center of the tire long before the outer edges are worn. I run 42 psi in it after using the same method. Results in nice even wear with the TPMS always on. I'm going to bribe the shop that mounts my next set of tires to program it differently than whats posted on the door sticker to keep the light off.
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's 1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)
|
|
|
Re: New Tires - Q on Pressure:
[Re: jbc426]
#2855810
12/05/20 07:47 PM
12/05/20 07:47 PM
|
Joined: Jan 2003
Posts: 12,801 Benton, IL.
DaveRS23
Master of nothing...
|
Master of nothing...
Joined: Jan 2003
Posts: 12,801
Benton, IL.
|
Or you can just put the rear TPMS sensors in a PCV tube, put a valve stem in it, seal the ends, and pump it up to the right pressure. If you ever need them out, just cut it open.
Cheaper than bribery.
Master, again and still
|
|
|
|
|