Tire pressure

[Cduncan5]

Hello just put my falcon at4 on size LT265/65/18 what should the pressure be? They came with 80psi that’s crazy high I think it’s the max pressure.

tks Craig

 

[2020FordRaptor]

Hello just put my falcon at4 on size LT265/65/18 what should the pressure be? They came with 80psi that’s crazy high I think it’s the max pressure.

tks Craig

Check what’s recommended on the tires. I usually go about 6 psi cold under whatever the max PSI says. Keeps better tire wear and gas mileage.

 

[UGADawg96]

Why LT tires on an ST ???

I run LT on my F150 and keep them at ~42 cold when not towing and bump them up to ~50 cold when towing a 6500lb travel trailer.

 

[Cduncan5]

The LT tires have more tread than the p rated ones LT are 17/32

 

[BrooseDaMoose]

You should go by the rating that on the sticker located on the inside of the drivers door jamb which is 33 psi.

 

[2020FordRaptor]

You should go by the rating that on the sticker located on the inside of the drivers door jamb which is 33 psi.

The door jamb is for stock wheel tire setups only. Wouldn’t apply to him since he’s running a completely different setup.

 

[BrooseDaMoose]

The door jamb is for stock wheel tire setups only. Wouldn’t apply to him since he’s running a completely different setup.

Oh, ok! That must be where the confusion comes from. I looked for an answer to this question a while back and some said to go by what the manufacturer puts on the tire and others said to go by what's on the door. I called Townfair Tire and a local shop (Rolands Tire) and they both said to go by what's on the door. But I get what your saying here. It's an altogether different set up than stock so therefore you would go by what's on the tire. That makes sense. So now, my tires say 36 psi. They are not the stock Michelin tire but are the stock size. Should I inflate to 33 or 36 psi?

 

[powerboatr]

Easy answer. You go by weight on each tire
And compare that to the manufacturer tire inflation guide.
If your on stock tires, the door jamb sticker is first guide
But anything different, you follow the respective tire manufacturer Inflation tables.
You need to weigh the vehicle and get accurate axle weights, in normal loaded setup
Then divide front axle in half and rear axle weight in half to get respective tire loading
You could do an all four weighing, but axle weight is faster route
Then compare the weight the tire is supporting to the recommended inflation at that particular manufacturer data
For example
If a tire has a load rating of 4k at max psi
But your only in the 2k range, then of course your cold pressure will be less

And you can also chalk your tread about 1/3 of circumference then slowly roll fwd on smooth surface like concrete or similar
And then look at the contact patch the chalk left behind
Then adjust psi to give you an even across tread contact.
And unless your vehicle is 50. 50 front and back
Then each axle will have different psi
My f150 carries normal heavy up front compared to rear
Rears run 31 and fronts 36
To maximize tire wear and pavement contact
And LT tires will be harsher. Because of sidewall layout
And load actually on the tire

 

[BrooseDaMoose]

Very informative! Thank you. Though that isn't such an easy answer to me. LOL!

 

[2020FordRaptor]

Easy answer. You go by weight on each tire
And compare that to the manufacturer tire inflation guide.
If your on stock tires, rhe door jamb sticker is first guide
But anything different, you follow the respective tire manufacturer Inflation tables.
You need to weigh the vehicle and get accurate axle weights, in normal loaded setup
Then divide front axle in half and rear axle weight in half to get respective tire loading
You coukd do an all four weighing, but axle weight is faster route
Then compare the weight the tire is supporting to the recommended inflation at that particular manufacturer data
For example
If a tire has a load rating of 4k at max psi
But your only in the 2k range, then of course your cold pressure will be less

And you csn also chalk your tread about 1/3 of circumference then slowly roll fwd on smooth surface like concrete or the like
And then look at the contact patch the chalk left behind
Then adjust psi to give you an even across tread contact.
And unless your vehicle is 50. 50 front and back
Then each axle will have different psi
My f150 carries normal heavy up front compared to rear
Rears run 31 and fronts 36
To maximize tire wear and pavement contact
And lt tires will be harsher. Because of sidewall layout
And load actually on the tire

Wow @powerboatr I would’ve just told @BrooseDaMoose yes or no. Very informative post.

 

[GearHead_1]

If you were to run an LT tire anywhere near the 80 lbs. they came with, on an Exploder, it will drive like an old plank wagon. I'd suggest you start at around 40 and chalk the tire.

 

[powerboatr]

Wow @powerboatr I would’ve just told @BrooseDaMoose yes or no. Very informative post.

well i have never been accused of being short on words
at least here you cant see my hands and arms being animated

its the aircraft guy in me
weigh it, set psi according to weight and psi scale developed by the builder of said tire
there simple

 

[FORZDA3]

Since the tires are much higher load range, run the stock tire pressures as those pressures are for the expected loads. Yes, the tires can handle MUCH higher loads and pressures, but thats simply overkill for the vehicle. Stock pressures will feel even harsher than stock due to the stronger sidewalls of the LT tire, even though they're taller. The best thing is to ditch those ridiculous tires.

 

[GearHead_1]

...The best thing is to ditch those ridiculous tires.

Couldn't agree more, strange tire choice for this vehicle.

 

[UGADawg96]

If you can return them, I'd suggest swapping back to SL or XL tires and keeping LT tires for trucks and offroaders.

 

[Cduncan5]

I bought them for the winter driving I have ALS and can’t put them on when it’s calling for snow so I got deep tread at tires so I can run them a little longer than just winter tires I will put stock tires on in the spring tks everyone