Now running an E rated tire! New tire pressure question.

[jditom]

Max PSI for an E rated tire is 80 lbs so I am running 60 lbs to start with which has ben recommended by discount tire etc. The problem I'm having is that I get a tire pressure warning that I am exceeding the recommended pressure. Anyone know how to deal with this??

Thanks

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[TickTock]

Let some air out.

Not a joke - just because the tires can go to 80 psi doesn't mean you should. The pressure is based on the weight of the vehicle. Set the pressure to that listed on the door jam regardless of tire rating.

 

[jditom]

I am running 60 PSI as recommend for E rated tires not there max which is 80. Running a higher pressure for the same load is what is recommended for a 10 ply E rated tire. This was set by Discount tire's calculator as well as Toyo's chart. Toyo explanation below.
LT-metric is an E rated tire. Below is what I have done.
So 10 lbs increase in psi for the same load when switching to a E rated tire.

P-metric to LT-metric

Example 4. Replace the OE P255/70R17 110S with a LT265/70R17 121S on a 2006 Ford F-150 XLT

4X4 Super Crew Cab.

OE Information (Obtained from the T.I.P.):

Vehicle: 2006 Ford F-150 XLT 4X4 Super Crew Cab

Tire Size (Front/Rear): P255/70R17 110S Inflation Pressure (Front/Rear) = 35 psi

Rim width = 7.5”

Using the TRA Load Inflation Table (see Table 8), at the OE pressure of 35 psi, the P255/70R17 has

a load carrying capacity of 2337 lbs. As this tire has been de-rated by the vehicle manufacturer by a

factor of 1.10 to account for its installation on a light truck, the actual load carrying capacity is 2125

lbs.

Table 8. TRA Load Inflation Table.

Table 8. TRA Load Inflation Table.

Load

Load

Inflation Pressure (PSI)

Tire Size

Index Tire Size Inflation Pressure (PSI)

Index

26 29 32 35

26 29 32 35

110 P255/70R17 2050 2160 2271 2337

110 P255/70R17 2050 2160 2271 2337

After confirming that the OE rim width is within the allowable rim width range for LT265/70R17 121S

After confirming that the OE rim width is within the allowable rim width range for LT265/70R17 121S

E/10, refer to the TRA LT Load Inflation Table. The ‘Single’ load values apply and this tire requires

E/10, refer to the TRA LT Load Inflation Table. The ‘Single’ load values apply and this tire requires

an inflation pressure of 45 psi (2255 lbs.) to maintain adequate load capacity.

an inflation pressure of 45 psi (2255 lbs.) to maintain adequate load capacity.

Table 9. TRA Light Truck Load Inflation Table.

Table 9. TRA Light Truck Load Inflation Table.

TIRE SIZE Single/Dual @ 35 PSI @ 40 PSI @ 45 PSI @ 50 PSI @ 55 PSI @ 60 PSI @ 65 PSI @ 70 PSI @ 75 PSI @ 80 PSI @ 95 PSI

TIRE SIZE Single/Dual @ 35 PSI @ 40 PSI @ 45 PSI @ 50 PSI @ 55 PSI @ 60 PSI @ 65 PSI @ 70 PSI @ 75 PSI @ 80 PSI @ 95 PSI

LT265/70R17 LT265/70R17 Dual Dual 1720 1720 1890 1890 2050 2050 2270 [C] 2270 [C] 2360 2360 2510 2510 2680 [D] 2680 [D] 2735 2735 2820 2820 2910 [E]

2910 [E]

LT265/70R17 LT265/70R17 Single Single 1890 1890 2075 2075 2255 2255 2470 [C] 2470 [C] 2595 2595 2760 2760 2910 [D] 2910 [D] 3005 3005 3100 3100 3195 [E]

3195 [E]

In summary, the 2006 Ford F-150 XLT 4X4 Super Crew Cab with an Open Country A/T LT265/70R17

121S E/10 must be inflated to 45 psi.

WARNING! Please note that size-for-size, LT-metric tires require higher air pressures to

carry equivalent loads of P-metric tires and that any failure to adjust air pressure to achieve the

vehicle’s load requirements will result in tire fatigue and eventual tire failure due to excessive

heat build-up. Due to the higher PSI requirements of LT-metric tires they may not be suitable for

replacing O.E. P-metric tires because of the ride harshness that results from higher PSI

requirements.

Additional information on replacement guidelines can be found in your tire owner’s manual as well as

the Rubber Manufacturers Association (RMA) at www.rma.org.

If there are any further questions, please contact our Consumer Relations at 800-442-8696.

 

[Travis64]

keep mine at 55 seem to wear perfect..wildpeaks 80 psi max

 

[jditom]

keep mine at 55 seem to wear perfect..wildpeaks 80 psi max

Are you getting a too high pressure alert on your truck?

 

[jditom]

keep mine at 55 seem to wear perfect..wildpeaks 80 psi max

I lowered mine to 56 and no more tire pressure warning.

 

[mongo]

Max PSI for an E rated tire is 80 lbs so I am running 60 lbs to start with which has ben recommended by discount tire etc. The problem I'm having is that I get a tire pressure warning that I am exceeding the recommended pressure. Anyone know how to deal with this??

Thanks

Is it actually a warming, or just saying 50 psi is recommended?

Stock all terrains when at max GVW or towing call for 65 psi, so over 50 isn't necessary wrong.

Tire loading rating depends on pressure. 50 psi may be underinflated for non-OEM tires which isn't good.

What is the tire model and numerical load rating?

 

[jditom]

I am running toyo open country III EV E rated 126.123S LT tires max load 3750 lbs

Correct and you can go to 80 with E rated tires if needed. So I got the red letter of a warning for overinflation when I was at 60. Nothing at 56 where I have them now. I have core wheels and changed my wheel setting to cyber wheels thinking that they came with ATR D rated tires which can be maxed at 65. Did the reset and same red warning. Going to wait a few days and put them at 60 reset and see what happens.

 

[mongo]

I am running toyo open country III EV E rated 126.123S LT tires max load 3750 lbs

Correct and you can go to 80 with E rated tires if needed. So I got the red letter of a warning for overinflation when I was at 60. Nothing at 56 where I have them now. I have core wheels and changed my wheel setting to cyber wheels thinking that they came with ATR D rated tires which can be maxed at 65. Did the reset and same red warning. Going to wait a few days and put them at 60 reset and see what happens.

LT275/65R20 ?
(I don't see 285/65/20 listed)
This table calls out equivilent load handling at 55 vs 50 and ~71 vs 65

https://www.toyotires.com/media/pxcjubjs/application_of_load_inflation_tables_20200723.pdf

 

[jditom]

You are correct and I was hoping not to get into using a slightly different size tire. But I wanted the LT in the EV format. The closest I could get is the 275/65R20 which is about a 1% difference in overall diameter which is minimal. For a 55lbs LT tire it's hard to beat. And I am not seeing much of a range hit and I am using energy used for a similar section of road not Wh/mi since the diameter is slightly off. Slightly smaller contact patch is worth the benefits for my use. 600 mi so far and I am very happy with the feel etc.

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