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Old Nov 5, 2017 | 06:26 PM
  #16  
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Originally Posted by 2009kr
I run 80/70 in my F450. My rear tires are rated for 10,880# at 70 PSI. I never have over 8000# on that axle. I'd like to run lower pressure, but my tires are only rated down to 70. I don't understand why Ford recommends 90/80.
Problem is Ford using class 5 rolling gear on what is still a class 3 truck. Those 225/70R19.5s are just fine on an F550 (or Ram 5500), but they're major overkill on a class 3 (14K GVWR). Rear tires on my Ram 3500 (LT235/80R17E) are never higher than 50 psi, and I usually run 45. Kind of a waste for an 80 psi-rated tire, but otherwise it would literally bounce all over the road.
 
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Old Nov 6, 2017 | 08:24 AM
  #17  
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Not sure I understand Toyo's pressure/weight charts. They seem designed to establish new tire pressures when changing tire size, using the OEM pressures times a factor....

My tires (LT275/70 R18E) are on page 25 of the .pdf. Am I to assume that if the truck is unloaded and I look for the front and rear axle weights in the table I can run the pressures at the top of those columns until I load the truck? For example, the lowest pressure shown is 35psi for 2070 lbs. So, picking an arbitrary example, if my axle weights are under 2070 lbs. I can run 35 psi? Just trying to understand how to use these tables.
 
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Old Nov 6, 2017 | 10:30 AM
  #18  
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Originally Posted by ~erik~
Not sure I understand Toyo's pressure/weight charts. They seem designed to establish new tire pressures when changing tire size, using the OEM pressures times a factor....

My tires (LT275/70 R18E) are on page 25 of the .pdf. Am I to assume that if the truck is unloaded and I look for the front and rear axle weights in the table I can run the pressures at the top of those columns until I load the truck? For example, the lowest pressure shown is 35psi for 2070 lbs. So, picking an arbitrary example, if my axle weights are under 2070 lbs. I can run 35 psi? Just trying to understand how to use these tables.
The weights in the tables are per tire, not per axle. To safely run 35 psi, your axle weight would have to be 4140. If you had a dually, you would use the "dual" weight number and multiply by 4 for the rear axle, but the single weight number multiplied by 2 for the front axle.
 
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Old Nov 6, 2017 | 10:33 AM
  #19  
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Originally Posted by KCJackson1
The weights in the tables are per tire, not per axle. To safely run 35 psi, your axle weight would have to be 4140. If you had a dually, you would use the "dual" weight number and multiply by 4 for the rear axle, but the single weight number multiplied by 2 for the front axle.
Yes, but with a slightly different spin - if your axle weight is 4140 or less you can safely run 35psi (using these "for example" numbers)
 
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Old Nov 6, 2017 | 02:33 PM
  #20  
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you guys with the diesels running below 60 in the front, do you get much feathering? ive had to settle in around 65-68 in my fronts to keep the outside lugs in check. rear 45-50 is good for me most of the time and rotation every 7-10k(every oil change) keeps them all in check. my truck is right at 9000 with tools though
 
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Old Nov 6, 2017 | 04:04 PM
  #21  
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Originally Posted by KubotaOrange76
you guys with the diesels running below 60 in the front, do you get much feathering? ive had to settle in around 65-68 in my fronts to keep the outside lugs in check. rear 45-50 is good for me most of the time and rotation every 7-10k(every oil change) keeps them all in check. my truck is right at 9000 with tools though
Mine was feathering at the factory pressures, have your alignment checked, the toe was off on mine. Bad alignment can cause feathering.
 
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Old Nov 7, 2017 | 07:38 AM
  #22  
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Had my 2017 F250 SuperCab LB 4 x 4 weighed last night as follows.
My tires are LT275/70R18E Goodyear A\T Wrangler Adventure
Weights are with me in truck (170 lbs)

Front Axle 4780 lbs
Rear Axle 2800 lbs

Gross weight 7580

So according to Toyo Load Inflation Tables provided by KCJackson1, I can run as low as approx

44-45 lbs in Front @ 2390 lbs per tire
35 lbs in Rear@ 1400 lbs per tire

Is this correct?
 
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Old Nov 7, 2017 | 08:03 AM
  #23  
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Originally Posted by kfederig
Had my 2017 F250 SuperCab LB 4 x 4 weighed last night as follows.
Weights are with me in truck (170 lbs)

Front Axle 4780 lbs
Rear Axle 2800 lbs

Gross weight 7580

So according to Toyo Load Inflation Tables provided by KCJackson1, I can run as low as approx

44-45 lbs in Front @ 2390 lbs per tire
35 lbs in Rear@ 1400 lbs per tire

Is this correct?
You didn't say what tire size you have, but if you got the above off the chart I suppose it's correct. Wonder what the affect on fuel mileage would be, though, running those pressures.

I wondered what the weight of my F250 CCSB 6.2 truck is, looks like going to the CAT scales is the only way to find out. The door sticker only gives GAWR per axle, and Ford specs online only give the base curb weight. No where does it give the front/rear bias, much less the actual axle weights for an empty truck.
 
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Old Nov 7, 2017 | 08:16 AM
  #24  
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kfederig, In a perfect world, yes. Load/inflation tables are intended to be guidelines, not an exact/absolute. Like any component, you do want some margin for error and potential light loads (other people, etc.) so that you're not constantly inflating and deflating your tires to get to the exact psi/load number. Pressures too low will cause wear and handling issues just like overinflation. But if you're generally running "solo and empty", you definitely do not need max inflation as indicated on the door jamb label.
 
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Old Nov 7, 2017 | 08:43 AM
  #25  
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Originally Posted by ~erik~
You didn't say what tire size you have, but if you got the above off the chart I suppose it's correct. Wonder what the affect on fuel mileage would be, though, running those pressures.

I wondered what the weight of my F250 CCSB 6.2 truck is, looks like going to the CAT scales is the only way to find out. The door sticker only gives GAWR per axle, and Ford specs online only give the base curb weight. No where does it give the front/rear bias, much less the actual axle weights for an empty truck.
Good catch erik
My tires are LT275/70R18E Goodyear A\T Wrangler Adventure
 
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Old Nov 7, 2017 | 08:48 AM
  #26  
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I have noticed approx 1.5 MPG decrease since reducing my tire pressure from

Front 60 / Rear 65 to
Front 56 / Rear 50.
But the ride has been much improved.

I may bump these up slightly to approx

Front 58 / Rear 52 or so

As a compromise for mileage etc.
 
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Old Nov 7, 2017 | 05:07 PM
  #27  
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Did the chalk test on my tires today, the stickered 60 psi front is right, i went down to 55 rear from 65 empty, 55t provide full contact.
 
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Old Nov 7, 2017 | 07:25 PM
  #28  
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Originally Posted by wb6anp
Did the chalk test on my tires today, the stickered 60 psi front is right, i went down to 55 rear from 65 empty, 55t provide full contact.

Interesting thanks for sharing!
 
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Old Nov 11, 2017 | 09:48 PM
  #29  
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Correct Tire inflation pressure

Originally Posted by kfederig
Could you please provide me a link to the PSI Tables for a set of Goodyear A\T Wrangler Adventures size P275\70R18E.
I have found a couple tables but they don't show my tire size. I'm a little confused at how to figure this out using the charts.
Here is the Goodyear tire inflation guidelines.
https://www.goodyeartrucktires.com/p...ion.pdf#page=6

Here is the link to the general information for most tires with inflation specs
Tire Inflation Tables

My 2017 F350 Dually says 70psi on the front and 65psi on rear. I have 60 psi on front and 55 psi on rear and the ride and the wear are better. I am still within the limits for loading weights.
 
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