Need weight and PSI chart for Sumitomo 719

[Kahoona]

Hi all!

Recently got new front tires. Sumitomo 719 16lpy 255/70/22.5


Seller inflated to max at 120psi. I suspect that may be too high. I cannot find any load and pressure chart for this tire. I did have an actual Sumitoma chart for my old 727's so I know they exist. The website for the company in the US only has a Max pressure chart. Anyone have a chart?

[Camp CA]

Contact tire manufacture for load / inflation table. Then weight each axle and determine the minimum inflation for each tire then add a safety margin......some add 10% and others increase the weight load.

[Old-Biscuit]

See pg 5 for 255/70/22.5 load inflation numbers

http://www.sumitomotire.com/upload/d...8c4605ecee.pdf

[MrMark52]

Aghhh young grasshopper! - what wonders come from the IRV2 search box!

http://www.sumitomotrucktires.com/up...uck_0118-2.pdf

[Kahoona]

These are for a different tire. I have the 727. Do you think they take the same inflation?

[Crasher]

I suspect that all tire brands of the same size and ratings will have the same or nearly the same psi requirements. The one exception I have found is the TOYO M144. Instead of 120 psi for max load, it is 125psi, but it also has a speed rating of 81 mph vs 175 on Michelin and others.

[MrMark52]

Originally Posted by Kahoona

These are for a different tire. I have the 727. Do you think they take the same inflation?

If your referencing the link I gave you - pg 5, 8th tire from the bottom in the chart - 255-70R/22.5.

I don’t see anywhere that defines what tire the chart relates to.

However, in the paragraph above the chart, it says something to the affect of “ the following table is recommended tire inflation from the wheel and tire manufacturer associations”.

Just to confirm (and re-educate myself once again) Crashers comment - I compared the load ratings vs cold inflation pressure for the Sumitomo’s to the chart for the tires on our coach (Hercules HRA’s) - same inflation values.

[Kahoona]

Originally Posted by MrMark52

If your referencing the link I gave you - pg 5, 8th tire from the bottom in the chart - 255-70R/22.5.

I don’t see anywhere that defines what tire the chart relates to.

However, in the paragraph above the chart, it says something to the affect of “ the following table is recommended tire inflation from the wheel and tire manufacturer associations”.

I am real sorry for perhaps not understanding but I think that this is for the ST788 and ST948 which are part of the S tech line. Mine is a 727. You are referring to the size which is 255-70/22.5 which is the same as the one on the list but the tires are a different line. I want to to find out what Sumitomo recommends for the 727 in case there is a difference. They may all have the same PSi recommended and if so I will then know for sure but in case there is a difference I want to check the table for the 727.

[jadatis]

I am able to make a customised pressure/ loadcapacity list for your tire.
Yust say how you want it, per axle, per tire or axle-end, and what reserve.

Then your task is to deterrmine the axle or axle-end loads acurately, and search them back in my made list for the needed cold pressure.

If you say nothing, I make them giving 90% of calculated loadcapacity for 99mph, and per axle given.
I determined this to give maximum reserve with still acceptable comfort and gripp.

Need nex from tires, can be found on sidewall.
1. maximum load or loadindex, for single and duall.
2. Loadrange to determine the referencepressure, if you find it pressure behind AT given.
You already gave 120 psi is called H-load/16plyrated.
3. Speedcode, yours most likely L for max 75mph.

[swampdog2]

I wonder how the tire mfg come up with those charts ? Humm let’s see ! Max weight 3192 at 80psi cold ! 3192 devided by 80=39.9 lbs per lb of pres so multiply 39.9 x what ever pres you have and that’s how much weight it will support!

[MrMark52]

Originally Posted by Kahoona

I am real sorry for perhaps not understanding but I think that this is for the ST788 and ST948 which are part of the S tech line. Mine is a 727. You are referring to the size which is 255-70/22.5 which is the same as the one on the list but the tires are a different line. I want to to find out what Sumitomo recommends for the 727 in case there is a difference. They may all have the same PSi recommended and if so I will then know for sure but in case there is a difference I want to check the table for the 727.

OK - your right, the chart doesn’t specify that it’s applicable to the 719.

Knowing the chart paralleled the Hercules HRA’s on our coach - I looked up the datapoint that we do know (120psi for 5510#’s single and 5070#’s dual) for the 719’s and compared to the table I referenced.

Again, inflation psi versus tire load capacities were the same.

But I also understand where your coming from - I get anal about stuff like this as well.

Sounds like an email or phone call is in your future next week.

[jadatis]

Lineair calculation is not that bad, but the official european formula, I got hold of end 2007, and went running with, comes to slightly lower pressures for the load, or slightly higher loadcapacity's for the pressure.

The old officially used in US, different for tirekind, come to even lower pressures for the load, or higher loadcapacity's for the pressure.
An article of IR J. C. Daws made me wiser, for tires with higher AT pressure like yours even a formula closer to lineair calc is needed.

In my lists I use a mayby to tight formula, verry close to lineair, so will certainly give not to low pressures.

But always a reserve is needed, and you have to determine the axle or axle-end loads acurately.
If you yust estimate them to low, even the best formula will lead to to low pressure for the load and speed, and you can wait on overheating of tire. This is only allowed ZERO times in tires use.
Can lead to tirefailure mayby only after 3 years, when the situation of of overheating is long forgotten.

So best is to let me make a list for you, then I do all the rocket science, and you ONLY have to determine the axle or axle-end loads acurately. The most tricky part in it all, and your responsibility.

[Kahoona]

Originally Posted by MrMark52

OK - your right, the chart doesn’t specify that it’s applicable to the 719.

Knowing the chart paralleled the Hercules HRA’s on our coach - I looked up the datapoint that we do know (120psi for 5510#’s single and 5070#’s dual) for the 719’s and compared to the table I referenced.

Again, inflation psi versus tire load capacities were the same.

But I also understand where your coming from - I get anal about stuff like this as well.

Sounds like an email or phone call is in your future next week.

Yes it is. I did try the USA number for Sumitoma one time but the phone tree did not acknowledge and response numbers I entered so I could not get anyone. Tried the distributor's email but they could not understand why I would want something other than a max psi chart for that tire. I need a number for the factory. Trying again today.

Originally Posted by jadatis

Lineair calculation is not that bad, but the official european formula, I got hold of end 2007, and went running with, comes to slightly lower pressures for the load, or slightly higher loadcapacity's for the pressure.

The old officially used in US, different for tirekind, come to even lower pressures for the load, or higher loadcapacity's for the pressure.
An article of IR J. C. Daws made me wiser, for tires with higher AT pressure like yours even a formula closer to lineair calc is needed.

In my lists I use a mayby to tight formula, verry close to lineair, so will certainly give not to low pressures.

But always a reserve is needed, and you have to determine the axle or axle-end loads acurately.
If you yust estimate them to low, even the best formula will lead to to low pressure for the load and speed, and you can wait on overheating of tire. This is only allowed ZERO times in tires use.
Can lead to tirefailure mayby only after 3 years, when the situation of of overheating is long forgotten.

So best is to let me make a list for you, then I do all the rocket science, and you ONLY have to determine the axle or axle-end loads acurately. The most tricky part in it all, and your responsibility.

Thanks. Will do

[jadatis]

I dont need exact tirename, my list is usefull for every tire with single 5510lbs AT 120psi for 75mph/120kmph max speed is speedcode L.

If now your tire is M speedrated for 81mph/130kmph, it will have lower maxload

5510lbs maxload is loadindex 140.
Then for M speedrate it will be 2 LI steps lower so LI 138 is maxload 5200lbs.

Compared lists of Michelin and Goodyear, and both most likely for max 75mph, and exact the same loadcapacity's for the pressure.
Gave at 80 psi / 4190psi most likely maxload of this size in E-load/10 plyrated.
All the other pressures the loadcapacity was calculated from that 80 psi with the still in US used formula, to my conlusions wrong.
Michelin, an original european brand, should know better, and use the for decades used european formula at least, used for all kind of tires, and since 2006 also in US, but only for P-tires. Before 2006 US used a realy bad formula for P-tires, 0,5 x referencepressure gave 71% of the maxload as loadcapacity, the european 57.4%,

Extra reason to let me calculate it, could mean that front you can use 120psi, with still no kidneybelt needed.

So look for loadindex or maxload, and speedcode. They are related. And check if 120 or 125 psi given on sidewall ir mayby even 130 psi.

I assume rear dualload axle, so also give for duall.