I'm make a road trip to Florida Friday with a fully loaded [weight wise] 98 RAM 1500. We're bringing a small lathe, tools, 60 gallon compressor etc. The tire placard says 41 psi, the tire says 80 psi. What pressure do you tire experts suggest?
Tire pressure?
- Thread starter demarpaint
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Shel_B
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Start here. The correct tire pressure depends on the load and the capacity of the tires. These charts will help, and there are other similar charts all over the internet. No need to guess or pay attention to other people's guesses.
I usually go by what the tire says for my cars. What the door post says is for a more comfortable ride. Having said that, 80 psi sounds a little high, maybe 65 psi.
Thanks for the replies. I was thinking 65 psi cold.
Shel_B
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How did you arrive at that number?
I went with ~ 80% of the max pressure on the tire. I did a search and it seems there are a lot of opinions based on little facts. That's also why I asked here, hoping a tire expert would chime in.
Shel_B
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How does that number compare with the figures in the charts I posted?
My F250 work truck placard said 75 psi rear, 70 front. I went to a scale and weighed the truck axles front and rear, and referencing a tire load table found I could safely run 55 rear, 50 front. Made a nice improvement in the ride.
Tire load table was quite useful in that instance.
Tire load table was quite useful in that instance.
I had 10 ply tires on my f-150 with a max psi of 62, the placard was specd for something like 36? Anyway, I kept them between 47-50 psi for normal use.
I'd of had zero worries going up higher towards max pressure, especially if I was hauling that much.
I'd of had zero worries going up higher towards max pressure, especially if I was hauling that much.
Just to clarify, I do NOT qualify as a tire expert. I do my research. I will see a tire expert today and I can ask him. I need better tires on my 1500.
Truck came from the factory with P rated tires but someone put LT 10 ply tires on it.
Bottom line is if you need more than ~50 psi to carry the load you have exceeded the payload on the truck. Most P-rated tires max at 51 psi, some are 50, some are 44.
Bottom line is if you need more than ~50 psi to carry the load you have exceeded the payload on the truck. Most P-rated tires max at 51 psi, some are 50, some are 44.
OVERKILL
$100 Site Donor 2021
This topic has been discussed extensively on this board.
As @Jimmy_Russells noted, it sounds like somebody put LT E-rated tires on a 1/2 ton, so you have to use the load tables to find the right pressure, as the placard no longer applies. The sidewall pressure does NOT dictate the proper pressure for the vehicle.
Here's an example from Toyo:
Peel the sticker off your truck and toss it. Its a sure bet the tires your truck came with went out of production a few years after it was made. And the new tires made today come with higher tire pressure ratings for a reason. Like, they are rated for higher load ratings, the will roll easier helping fuel economy, the will run cooler and have less drag.Especially when going around corners. Keeping the pressure up will also help them last longer.,,
To the OP, if you are carrying something substantially above factory load, then I would look at the load tables provided by this guy for the proper tire pressure.
OVERKILL
$100 Site Donor 2021
No, the sticker is fine if he had the same size, and type (P-Metric) tires as originally fitted to the vehicle. The issue is that somebody has removed those and fitted it with LT's, so the proper inflation pressure now needs to be determined using the load tables.
Honestly I didn't see the chart. I'll have to check it out. Thanks.
It looks like I have to consider upping the pressure from the 80% figure. We'll calculate weight and go from there.
OVERKILL
$100 Site Donor 2021
What's the factory size on the placard?
The truck in question is my brother's, I'm helping him move this weekend so I'm not 100% certain of the tire sizes. IIRC it's 245/75R16 on the placard. I'm not sure on the LT tire size on it now, only that it's a 16" tire with 80psi on it.
