I recently installed new tires Hankook Dynapro ATM on our 08 Envoy. The new tires are the same size, P245/65/17, as the OE Michelin Cross Terrains. The door label says 35lbs rear and 30 lbs front. The difference is the new tires state a max load of 2039lbs. AT 44psi. The OE is max load 2039lbs max pressure 35psi. I remember reading in another post that for P rated tires max load is achieved at 35psi. Is this correct even though my tires state max load @ 44psi? I currently have 35 in the rears and 32 in the fronts, but when summer gets here I will be towing a boat and want to be sure I am OK. If I do need to inflate the rears to 44psi to carry the load what should the fronts be at based on the door label? Thanks
Tire Inflation ?
- Thread starter gmctodd
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Sorry gmctodd, but you need to look at the sidewall of your new tires again.
Your new tires will say: Max Load XXXX, max pressure 44 psi - notice that there is no relationship expressed.
Your old tires said: Max load XXXX at 35 psi - relationship expressed, but there is no indication what the maximum pressure would be.
These tires have equivalent load carrying characteristics, so the pressure on the vehicle tire placard would apply.
But if you want to use a few more psi, that's OK.
Your new tires will say: Max Load XXXX, max pressure 44 psi - notice that there is no relationship expressed.
Your old tires said: Max load XXXX at 35 psi - relationship expressed, but there is no indication what the maximum pressure would be.
These tires have equivalent load carrying characteristics, so the pressure on the vehicle tire placard would apply.
But if you want to use a few more psi, that's OK.
No my new tires say Max load 2039 AT 44 psi. the old ones say max load 2039 max pressure 35 psi. I will take pictures if needed.
Thanks
edit: I have pics whats the easiest way to add them?
Thanks
edit: I have pics whats the easiest way to add them?
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Originally Posted By: gmctodd
No my new tires say Max load 2039 AT 44 psi. the old ones say max load 2039 max pressure 35 psi. I will take pictures if needed.
Thanks
edit: I have pics whats the easiest way to add them?
Upload the images to photobucket, then use the icons above to insert an image.
WORD OF WARNING: Be careful about the size to the image. Try previewing the post first to see if the image fits in the space provided.
No my new tires say Max load 2039 AT 44 psi. the old ones say max load 2039 max pressure 35 psi. I will take pictures if needed.
Thanks
edit: I have pics whats the easiest way to add them?
Upload the images to photobucket, then use the icons above to insert an image.
WORD OF WARNING: Be careful about the size to the image. Try previewing the post first to see if the image fits in the space provided.
Ok here are a couple of pics I snapped. The first is the Michelin OE taken off
notice a max load and max psi but no relationship
Next the newly installed Hankook DynaPro ATM
It's a little blurry, but it specifically states max load AT 44 PSI
Next the newly installed Hankook DynaPro ATM
Originally Posted By: Gregory
Org Max Load*Sticker's Rec P.S.I./Org Max P.S.I*New Max P.S.I/New Max Load=new psi
No, no!! That is completely wrong:
http://www.barrystiretech.com/loadtables.html
Originally Posted By: gmctodd
Ok here are a couple of pics I snapped. The first is the Michelin OE taken off..... notice a max load and max psi but no relationship........
Well, the image didn't come through clear enough to read. Nevertheless, Thanks for the photos. Michelin CAN express the relationship that way if they chose - and that is not the way they usually do it.
Originally Posted By: gmctodd
...........Next the newly installed Hankook DynaPro ATM....... It's a little blurry, but it specifically states max load AT 44 PSI
That one I can read. And I can tell you it is wrong. It will take some time for me to contact my friends at Hankook to get them to correct that.
Nevertheless, the types of tires you are dealing with, the placard pressure applies.
Org Max Load*Sticker's Rec P.S.I./Org Max P.S.I*New Max P.S.I/New Max Load=new psi
No, no!! That is completely wrong:
http://www.barrystiretech.com/loadtables.html
Originally Posted By: gmctodd
Ok here are a couple of pics I snapped. The first is the Michelin OE taken off..... notice a max load and max psi but no relationship........
Well, the image didn't come through clear enough to read. Nevertheless, Thanks for the photos. Michelin CAN express the relationship that way if they chose - and that is not the way they usually do it.
Originally Posted By: gmctodd
...........Next the newly installed Hankook DynaPro ATM....... It's a little blurry, but it specifically states max load AT 44 PSI
That one I can read. And I can tell you it is wrong. It will take some time for me to contact my friends at Hankook to get them to correct that.
Nevertheless, the types of tires you are dealing with, the placard pressure applies.
Originally Posted By: CapriRacer
Nevertheless, the types of tires you are dealing with, the placard pressure applies.
I agree. As someone who had the same vehicle, the same size tires and towed a trailer from San Diego to Seattle - go with the placard or do like I did and add about 3 - 4 pounds to the rear. The vehicle handled well and I had no problems!
Nevertheless, the types of tires you are dealing with, the placard pressure applies.
I agree. As someone who had the same vehicle, the same size tires and towed a trailer from San Diego to Seattle - go with the placard or do like I did and add about 3 - 4 pounds to the rear. The vehicle handled well and I had no problems!
Originally Posted By: YZF_Eric
44-PSI is the max pressure allowed for the tire. Right? So I wouldn't want to inflate more than 44.
Exactly.....that's how I've always ran. Start at the "max" and work your way down.
At the MAX PSI your car may feel like it's gliding all over the road, and you will likely feel every little bump in the road (not necessarily a bad thing, it'll keep you awake lol)....just remember that "max" PSI is for "cold" tires, not been driven more than a mile. So, you'll want to check the tires first thing in the morning and adjust in your driveway using a compressor/manual pump/etc......or get the "cold" reading, then drive the car to the nearest air hose, and get the "warmed up rating" and figure the psi difference, and adjust from there.
But yea, definitely don't inflate more than what the TIRE side wall has marked.....
44-PSI is the max pressure allowed for the tire. Right? So I wouldn't want to inflate more than 44.
Exactly.....that's how I've always ran. Start at the "max" and work your way down.
At the MAX PSI your car may feel like it's gliding all over the road, and you will likely feel every little bump in the road (not necessarily a bad thing, it'll keep you awake lol)....just remember that "max" PSI is for "cold" tires, not been driven more than a mile. So, you'll want to check the tires first thing in the morning and adjust in your driveway using a compressor/manual pump/etc......or get the "cold" reading, then drive the car to the nearest air hose, and get the "warmed up rating" and figure the psi difference, and adjust from there.
But yea, definitely don't inflate more than what the TIRE side wall has marked.....
Dont inflate the tires above what the placard says regardless of what the tire says.
Just go by the placard. The pressures are based on the ride characteristics and vehicle loading the car maker has designed the car for.
My wife's Golf says 30 front 41 rear. I go up a bit in the front to 32 because it improves the handling just a bit but leave the rear at 41.
Of course with American cars, depending on the vehicle type, you've got to remember that sometimes the tire pressure was decided on base on ride characteristics. For example, my Buick calls for 30psi at all 4 wheels. Why? In part because its an old man mobile and GM wanted a softer ride. I get better tire wear and better handling running the tires at 33psi. The CS4s on it are rated at 44psi max.
My wife's Golf says 30 front 41 rear. I go up a bit in the front to 32 because it improves the handling just a bit but leave the rear at 41.
Of course with American cars, depending on the vehicle type, you've got to remember that sometimes the tire pressure was decided on base on ride characteristics. For example, my Buick calls for 30psi at all 4 wheels. Why? In part because its an old man mobile and GM wanted a softer ride. I get better tire wear and better handling running the tires at 33psi. The CS4s on it are rated at 44psi max.
The placard is minimum cold pressure, the tire sidewall is maximum cold tire pressure, never have your tire below the pressure on placard. You will get better performance/handling on both wet and dry with 2-6PSI above placard. You also need to adjust tire pressure (increase few PSI) when driving condition change, such as full load and long trip and/or towing ... as oppose to daily drive.
Todd
You might feel better stability when towing if you inflate up to 44. Determine which feels best (most stable, safest) for your rig.
You might feel better stability when towing if you inflate up to 44. Determine which feels best (most stable, safest) for your rig.
Just a note for CapriRacer here too - I checked my Hankook Winter I-Pikes that I took off the explorer this weekend, and the load and pressure is listed like the OP's. Such and such max weight AT such and such PSI. Not correct, but that is how they have it shown on the tire.
Since it is a standard P-series tire, I just make the assumption that max weight is possible at 35 psi, with max pressure allowed up to 44 psi for handling and wear purposes. (Tire placard in this case is at 30 psi, which still results in some increased center wear on the rears - this is on an Explorer that was part of all the Firestone fun with the 26 psi placcards.)
Since it is a standard P-series tire, I just make the assumption that max weight is possible at 35 psi, with max pressure allowed up to 44 psi for handling and wear purposes. (Tire placard in this case is at 30 psi, which still results in some increased center wear on the rears - this is on an Explorer that was part of all the Firestone fun with the 26 psi placcards.)
Personally, I run as high as I can (up to sidewall max) without causing center tread wear and/or it not feeling right. For my Jeep (tires rated to 44psi), I'm currently at 44 psi front, 40-41 psi rear (front end is a bit heavier).
Originally Posted By: motorguy222
Dont inflate the tires above what the placard says regardless of what the tire says.
I'll give you a good example of exceptions to that rule-my old Mercedes came with tires that had a maximum pressure rating of 32 PSI-the Continental winter tires I use in winter have a maximimum rating of 51 PSI-I just add the difference (19 PSI) to the placard #s & use that as a starting point-and ended up running 40 front & 43 rear.
Dont inflate the tires above what the placard says regardless of what the tire says.
I'll give you a good example of exceptions to that rule-my old Mercedes came with tires that had a maximum pressure rating of 32 PSI-the Continental winter tires I use in winter have a maximimum rating of 51 PSI-I just add the difference (19 PSI) to the placard #s & use that as a starting point-and ended up running 40 front & 43 rear.
Originally Posted By: bullwinkle
Originally Posted By: motorguy222
Dont inflate the tires above what the placard says regardless of what the tire says.
I'll give you a good example of exceptions to that rule-my old Mercedes came with tires that had a maximum pressure rating of 32 PSI-the Continental winter tires I use in winter have a maximimum rating of 51 PSI-I just add the difference (19 PSI) to the placard #s & use that as a starting point-and ended up running 40 front & 43 rear.
Just because the tire says 51psi does not mean that is the maximum load. Ill give an example using my car and the non-factory tires I picked out.
Factory P225/60R16 97T MAX LOAD 1609#@35psi MAX PRESS 35psi
Placard Pressures: 32psi=1521# 35psi=1609#
Winter 215/65R16 98R MAX LOAD 1653#@36psi MAX PRESS 44psi
Calculated Pressure: 33psi=1543# 36psi=1653#
Summer 255/45R18 103Y XL MAX LOAD 1929#@42psi MAX PRESS 50psi
Calculated Pressure: 32psi=1543# 34psi=1628#
Originally Posted By: motorguy222
Dont inflate the tires above what the placard says regardless of what the tire says.
I'll give you a good example of exceptions to that rule-my old Mercedes came with tires that had a maximum pressure rating of 32 PSI-the Continental winter tires I use in winter have a maximimum rating of 51 PSI-I just add the difference (19 PSI) to the placard #s & use that as a starting point-and ended up running 40 front & 43 rear.
Just because the tire says 51psi does not mean that is the maximum load. Ill give an example using my car and the non-factory tires I picked out.
Factory P225/60R16 97T MAX LOAD 1609#@35psi MAX PRESS 35psi
Placard Pressures: 32psi=1521# 35psi=1609#
Winter 215/65R16 98R MAX LOAD 1653#@36psi MAX PRESS 44psi
Calculated Pressure: 33psi=1543# 36psi=1653#
Summer 255/45R18 103Y XL MAX LOAD 1929#@42psi MAX PRESS 50psi
Calculated Pressure: 32psi=1543# 34psi=1628#
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Like Colt45, I also take exception to bullwinkle's post.
First, there was a time where standard passenger car tires maxed out load-wise at 32 psi. That is no longer true - and bullwinkle was correct in pointing that out - but that changeover took place in the 1970's just about the time vehicle tire placards came into use - which makes his whole post an interesting, but obscure factoid.
However, the proper way to deal with that is to calculate the load carrying capacity based on the tire size and pressure used at the time and then back calulate - from a tire load vs inflation table - what pressure is neede to carry the same load.
NEVER - let me say that again - NEVER use the pressure on the sidewall for any sort of calulation, except for what it says - MAXIMUM. (And of course, just by coincidence.) Use the load tables for the calculation.
First, there was a time where standard passenger car tires maxed out load-wise at 32 psi. That is no longer true - and bullwinkle was correct in pointing that out - but that changeover took place in the 1970's just about the time vehicle tire placards came into use - which makes his whole post an interesting, but obscure factoid.
However, the proper way to deal with that is to calculate the load carrying capacity based on the tire size and pressure used at the time and then back calulate - from a tire load vs inflation table - what pressure is neede to carry the same load.
NEVER - let me say that again - NEVER use the pressure on the sidewall for any sort of calulation, except for what it says - MAXIMUM. (And of course, just by coincidence.) Use the load tables for the calculation.
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