Tire load range


#1

I bought load range E tires and put them on a light little 89 4runner. My thought is I messed up because the vehicle is so light and in on winter roads. Should I have stayed with load range C.?
Will it really make much difference??


#2

D hard and stiff
C softer and holds the road better?


#3

You don’t change the inflation pressure, right? So they would not be too much stiffer, I’d think.


#4

They are rated to take 60 or 80 psi. I’m thinking just run them about 35psi.
Sticker on door says like 29 front 30 something rear.

I’m tired of fighting with tires. $800 later still not happy


#5

You will notice a different ride, even with psi down to meet your truck.
I had Es on my 92 Explorer…aired down…but the ride was harsher.
Otherwise not a bad thing aside from the unneeded extra expense.


#6

Yeah, follow the sticker on the door, maybe a bit more.


#7

Thanks


#8

There is a whole lot wrong here.

First is that changing from a P type tire to an LT type tire IN THE SAME SIZE requires 15 psi more for the same load carrying capacity.

Second is that we don’t know the tire sizes involved - and I’ll bet they are different.

In other words, we just don’t know enough to say what inflation pressure should be used. We need more information.


#9

Factory - P225/75R15
Current - LT245/75R16

Front - 26 PSI
Rear - 35PSI (Factory Recommendations)

1989 Toyota 4runner has been lifted


#10

@CapriRacer - Why do LT tires require more pressure? I (obviously) didn’t know that.


#11

I don’t believe they do.
They will take more pressure to carry a load


#12

@badbearing

We have Load range E tires on many of our trucks at work, in the size LT245/75R16

But they came from the factory with those tires

The tire placard usually says 50psi front, 80psi rear


#13

Right. Heavier rig, Heavier tires


#14

As phrased by BadBearing, in order to carry the same load, an LT tire needs to use 15 psi more for the same size.

Why?

LT tires are more like their bigger cousins, the over-the-road truck tires. They can carry a lot of load compared to how big they are. Because rubber is a visco-elastic material, it can be deformed under stress - and some of this deformation is permanent. For passenger car tires, this usually isn’t a problem, but for LT tires (which can carry a lot more load), this becomes a real design limitation.

Ergo, LT tires are rated for less deflection - and therefore more pressure for the same load carrying capacity.


#15

And to respond to BadBearing’s post on what tire sizes he is dealing with

If the original tires were P225/75R15 (Tire Guides says that was one of the possibilities), and inflated to 26 psi front / 35 psi rear (Tire Guides agrees with the front, but lists the rear as 29 psi), then in order to carry the same load an LT245/75R16 needs to use … .

Well isn’t this interesting. It turns out that it is the same. This is in spite of the larger physical dimensions.


#16

The wheels on a light duty truck are designed for a maximum pressure of 45 psi. Those wheels cannot withstand the high pressure that E load range tires are designed for. The wheels can burst at that pressure. And that is not idle speculation. I have seen the damage on several occasions.


#17

. Wrangler DuraTrac tires feature a rim lock that helps prevent wheel slip throughout the life of the tire and offers a built-in rim protector to help protect wheels from accidental damage on- and off-road.


#18

The above may not help but i have a hard time believing the rims would give out.
I with and old 4runner i should really never have a reason to inflate over 45psi


#19

@Rod Knox

Wheels are J16X7JJ DOT CMC 10 99 HM 13
But i cant find good info on them

Where do you get your info


#20

and what is considered a “light duty” truck. Im guessing 3/4 or 1 ton falls into this category and they oftet run load range D tires