Dodge Challenger Forum banner

1 - 20 of 23 Posts

·
Vendor
Joined
·
768 Posts
Discussion Starter #1
Myth or Fact: The pressure listed on the tire sidewall indicates the recommended pressure?

Myth or Fact: Tire pressure does not need to be regularly checked for vehicles equipped with TPMS?

When it comes to tires, there is a lot of misinformation out there. Check out our write-up linked below where we dismiss some of the common myths surrounding tires and tire safety.


 

·
Registered
Joined
·
1,078 Posts
I believe sidewall is max. pressure. Good to know when storing for winter to help prevent flat-spotting.

TPMS has made me lazy. I don't physically check it as much as I should now :)
 

·
Registered
Joined
·
1,126 Posts
I check my air pressure every time I gas up but do depend on the tire pressure monitoring system to check if their all the same and right pressure.
 

·
Premium Member
Joined
·
2,974 Posts
With the FCA TPMS system you better not count on the tire pressures showing in the correct position.
 

·
Registered
Joined
·
548 Posts
I have no tpms, ditched them a long time ago. I check my pressure as I feel needed and when changing wheels(which is pretty often). For optimal pressure I use a heat laser to get equal heat across the tread after some miles of driving. There is no better way imo.


Sent from my iPhone using Tapatalk
 

·
Registered
2018 Scat Pack SHAKER in Plum Crazy
Joined
·
1,179 Posts
I know of a lot of people that inflate to the max pressure on the tire, they will not listen.
As for TPMS, they are a PITA, BUT saved me a lot of hassles twice. Getting an out of the blue, warm day "1 tire pressure low" alert right before getting on a highway middle of Ohio, found a safe place to pull over, get out and watched a tire deflate due to a bolt in it. (2002 Chrysler Town and Country Limited)
2nd time was on the Parkway east of Pittsburgh light came on, I pulled off next exit, into an apartment complex, and watched a tire go flat, (nail?).
That was in my 2006 Charger R/T. Both were pre-mandated TPMS.
 

·
Registered
Joined
·
5,161 Posts
I know of a lot of people that inflate to the max pressure on the tire, they will not listen.
Here's the thing with that, it can make the car rattle plus the fact that my tire might say max. 45 lbs but I check it in the garage and it says 40lbs or even in the dead of winter say 35lbs, so I fill it to the max. and then leave and drive it, as the tires heat up I could have 50 or 55lbs in it. Some people just do not have common sense.

Plus a Higher Tire pressure means less contact with the road, a smaller foot print as each square inch of tire is supporting MORE of the cars weight.
 

·
Registered
Joined
·
1,232 Posts
There is a reason why it says "max tire pressure" on the tire - not "recommended tire presure"! ;-) Obviously the tire can fit MANY vehicles, so there is no way they can print the recommended pressure on the tire - because it all depends on what vehicle it is installed on.

I can't believe people have a hard time understanding this!
 

·
Registered
Joined
·
328 Posts
Myth or Fact: The pressure listed on the tire sidewall indicates the recommended pressure?

Myth or Fact: Tire pressure does not need to be regularly checked for vehicles equipped with TPMS?

When it comes to tires, there is a lot of misinformation out there. Check out our write-up linked below where we dismiss some of the common myths surrounding tires and tire safety.



OK, my tire size has been changed.


I have an SXT (2017) but I have 275/40's on it now. What is the new recommended tire pressure with that combination.


Thanks.
 

·
Registered
Joined
·
13,965 Posts
Yep, the good old load chart that most have never heard of.



OK, my tire size has been changed.


I have an SXT (2017) but I have 275/40's on it now. What is the new recommended tire pressure with that combination.


Thanks.
The chart shows the load capacity of the tire at various pressures. The more pressure the more load it can carry and a larger tire will usually carry more load so it may need less pressure.

So armed with the GAWR weights from your door sticker, you divide by 2 to get the weight carried by each tire then look across for the required pressure. Do this for the front and rear axle.

Don't know the SXT weights, mine is 2,800 lbs per axle so each tire needs to be able to carry 1400 lbs. Find the tire size on the chart then locate the pressure needed to carry 1400 lbs and that's all there is to it. Some may add 5 psi for higher speeds.

Now finding these charts online for passenger tires not easy, you might have to email the manufacturer and request one.

The good news is that your standard 32 psi will probably work but it's fun and interesting going thru the process and for large heavy vehicles, it's absolutely essential.




Sent from my SM-N960U using Tapatalk
 

·
Registered
Joined
·
1,232 Posts
Another option.... When I put non-standard-sized wheels/tires on my 2018 GT, I emailed the tire manufacturer (Continental in my case) and gave them my car info, the stock tire size/recommended pressure and the new tire size - and asked them what the recommended pressure should be for the new tire size. They emailed me back with the recommended pressure. Nice and easy.

In my case, the new tire size wasn't very different from the stock size (235/60/18 new vs 235/55/19 stock), so the recommened pressure wasn't very different from the stock recommended pressure (31psi new vs 30psi stock).
 

·
Registered
Joined
·
607 Posts
The chart shows the load capacity of the tire at various pressures. The more pressure the more load it can carry and a larger tire will usually carry more load so it may need less pressure.
Hmm, I usually just Google "Tire load chart" when I want to get numbers for some new combination, and haven't had any trouble finding them.

Anyway, as you point out, sort of, is that it's the amount of air in a tire that supports the load. Not the tire.
It may sound strange at first, but the tire is only a container for the air, not really carrying any load.

Volume is the key, letting a small tire carry heavier loads by increasing the pressure. A larger tire can contain the same volume (support the same weight) at a lower pressure.

I probably didn't explain this very well, but hopefully someone will understand it.
 

·
Registered
Joined
·
1,232 Posts
This may help too...

Brief description from another site where I found this:

I had the same question and came across this*awesome paper by Toyo Tires (see page 7). This isn't specific to their tires. Basically you use your OEM tire specs to look up the corresponding load front/rear. You then use the same table to find your new tires and reverse lookup the PSI from the*same*load front-rear.

The example they give:

OEM tire:*P225/60R18 93W*with door sticker saying 32 psi front / 29 psi rear. The table corresponds this tire/pressure combination to 1354 lbs front / 1272 lbs rear.

New tire*245/40ZR18 97Y*to handle loads of 1354 lbs front / 1272 lbs rear, the table says you need 35 psi front and 32 psi rear.


Site referenced:

https://toyotires-1524598101.netdna-ssl.com/media/1541/application_of_load_inflation_tables_20151020.pdf
 

·
Registered
Joined
·
328 Posts
OK, thanks for the replies.


I see that the tires are actually sport truck tires. Not a big deal I guess, but probably don't ride as nice.


They are Toyo Proxies III, but that should actually have been stated ...Proxies ST III when I got them. The size is 275/40 x20 106W from the sidewall. They are ISO metric. The load rating is the 106 part.


My sticker says the GVWR per axle is 2810lbs, so 1405 per tire. On the Toyo load chart the closest is 1455lbs at only 23psi.


I guess I'm pretty safe at 32psi. That takes the load rating all the was over 1800lbs.


I've been running them a little higher because I get better gas mileage, but I'm thinking that I might be bulging the tire and wearing the centers. I'm going down to 32psi.


I don't like the idea of going any less, but I guess 30psi wouldn't kill me and would provide a softer ride.


Any comments?


Edit: While I don't hate my tires, I think I'll be going with Continental ExtremeContact DWS 06 in the same size next time around. I've got lots of tread left, but the Connies are for cars specifically and the review comment about both comfort, traction (wet and dry) and mileage.
 

·
Registered
Joined
·
607 Posts
Running XL tires, as the Proxes III seems to be, when there's no extra load requirement is a sure way to kill the ride comfort.

I ended up with the XL version of a tire I knew works and rides well (they thought they did me a favor) on a Jeep Cherokee XJ. Well, it rode like crap with those tires.
And unfortunately you really can't air your way down to compensate - the carcass is just too stiff.
 

·
Registered
Joined
·
1,232 Posts
I wouldn't say that is always the case. I have the Continental ExtremeContact DWS-06 tires in a size of 235/60/18 - and they are considerd "XL" tires (XL are the only option in that size). But I must say - they ride great. No complaints about these tires at all. They replaced the stock Michelin 235/55/19 tires and there is virually no difference in ride quality. They also get great ratings for both comfort and noise.
 

·
Registered
Joined
·
607 Posts
Indeed, it's not always the case, but usually.

I've had very good luck with the DWS tires (not that they were extra load). Maybe the one thing that really swayed me after the demonstration on both dry and wet tracks was that they were "dumbed down for the American market".

In other words, they were made to give ample warning before breaking loose, instead of letting go with a snap.
Consequently I ended up a bit sideways on the canyon roads a couple of times, but to me that is so much nicer than being able to go 0.3 mph faster through a corner...but maybe end up in a ravine if going 0.31 mph faster.
 

·
Vendor
Joined
·
768 Posts
Discussion Starter #20
OK, my tire size has been changed.


I have an SXT (2017) but I have 275/40's on it now. What is the new recommended tire pressure with that combination.


Thanks.

We would be happy to check the recommended pressure for you but we would need the new tire load rating as well as which model you have.
 
1 - 20 of 23 Posts
Top