Tire and pressure advice

[mrfoamy]

F350 SCLB with 3000# camper. I replaced the LT275/70R18E A/T factory tires with Toyo 35x12.50R18LT 12PR Load Rating F to allow lower pressures off-road, especially on washboard. The problem is that the Toyos are very noisy on asphalt, so noisy that I am considering replacing the Toyos with the Continentals.

Replacing the Continentals on the FRONT ONLY should improve the noise noticeably yet still might allow optimal deflation.

Questions: Anybody have experience doing this? What are your suggested pressures at highway speeds and importantly at, say 25 mph off-road. That is low-pressure washboard territory. I’m not too worried about the F rated tires but the E rated tires, yes. In case of a flat they should all be interchangeable. Opinions please.

 

[nitro_rat]

Is the truck 4wd or 2wd? Plot your actual weight vs tire capacity to find optimum inflation pressure. Double check with chalk. Plenty of info out there on how to do this if you search a little...

 

[mrfoamy]

Yeah, I was hoping to avoid a 2-4 hour research project, since so many people here are amazingly knowledgeable. I had trouble finding the correct load table at Toyo and figured maybe I could save a few hours.

 

[mrfoamy]

oh, 4WD of course.

 

[nitro_rat]

I thought I'd save myself a couple hours typing by telling you what to search for, it's been written plenty of times before.

You probably can't be bothered to read this:

TOYO TIRES - Europe

Toyo Tires Official Web site

www.toyotires.com

or this:

Using The Chalk Method for Determining PSI | Interco Tire

Using The Chalk Method for Determining PSI - NOTE. This article is posted for reference only. You should always consult with your local tire installation professional(s) when you have questions about your tires.

www.intercotire.com

Neither did I but I found both those links with about 15 seconds of "searching."


Don't put mismatched tires front and rear, it's a bad idea.

 

[Buliwyf]

What's the max inflation?

If it's 80, set the rears to 88. Fronts to 70-75. Make sure truck isn't sitting tail down at all. An inch of rake would be nice, still.

 

[mrfoamy]

I thought I'd save myself a couple hours typing by telling you what to search for, it's been written plenty of times before.

You probably can't be bothered to read this:

TOYO TIRES - Europe

Toyo Tires Official Web site

www.toyotires.com

or this:

Using The Chalk Method for Determining PSI | Interco Tire

Using The Chalk Method for Determining PSI - NOTE. This article is posted for reference only. You should always consult with your local tire installation professional(s) when you have questions about your tires.

www.intercotire.com

Neither did I but I found both those links with about 15 seconds of "searching."


Don't put mismatched tires front and rear, it's a bad idea.

TOYO TIRES - Europe

Toyo Tires Official Web site

www.toyotires.com

Yes, I had that. So you are recommending 30psi, then...or exactly what? Based on 35X12.50R18LT.

And "Don't put mismatched tires front and rear, it's a bad idea." Your opinion is referenced ...where?
The many expert opinions are exactly what I am seeking. I'll separate the wheat from the chaff.

 

[nitro_rat]

I'm not making any recommendation. I have no idea what your truck weighs.

You can make a graph using the load capaicty and max inflation pressure on the tires sidewall to give you a safe inflation pressure (0 psi = 0 load, max psi = max load). The Toyo stuff should already have the number in it but you have to know what the vehicle weighs. Don't make a rats ass if it's a F-350 or a Yugo, inflation pressure is based off of load capacity and weight.

My recommendation on not mixing tire types front to back is based on personal experience (due to lack of working capital rather than choice; I choose not to walk) as well as the fact (yes fact, not opinion) that it looks ghey.

If you want someone to tell you what pressures to run post the following:

• Tire rated max load capacity (found on sidewall)
• Tire rated max pressure (also found on sidewall)
• Front and rear axle weights of your truck loaded as you normally drive it.

That last one you'll have to do some leg work for. Also note that the calculated pressures will only be valid for that particular loaded weight.

I hope you find what you're searching for...

 

[mrfoamy]

What's the max inflation?

If it's 80, set the rears to 88. Fronts to 70-75. Make sure truck isn't sitting tail down at all. An inch of rake would be nice, still.

I failed to emphasize the low pressures for off road, your recommendations, for asphalt going to the max is the safe bet.

 

[rayra]

You've got a weird way of asking for help. People don't generally respond well to that combination of demand and dismissal.

You seem to be looking for some mathematical formula to relate your load to lowered pressure. I'm not aware of such a thing being available, nor have I heard of such a juxtaposition of concerns in my 56yrs.

To my understanding max load at max pressure is just that. And anything less in either column is acceptable. As for lower inflations for off-road, the rule of thumb is lowered speeds. And especially upon return to pavement. But that's mostly to do with rolling resistance and heat. And not strictly load ratings.

Good luck with your quest.

 

[Buliwyf]

For offroad pressures, I just use a stick.

Usually a 1x1, but others have thier own ideas for what to use. Run it over, eyeball the tire flex.

 

[jadmt]

One reason not to mix brands as all brands are not sized the same. Some tires run truer to size others run small. Kind of like shoe brands.

 

[Regcabguy]

F350 SCLB with 3000# camper. I replaced the LT275/70R18E A/T factory tires with Toyo 35x12.50R18LT 12PR Load Rating F to allow lower pressures off-road, especially on washboard. The problem is that the Toyos are very noisy on asphalt, so noisy that I am considering replacing the Toyos with the Continentals.

Replacing the Continentals on the FRONT ONLY should improve the noise noticeably yet still might allow optimal deflation.

Questions: Anybody have experience doing this? What are your suggested pressures at highway speeds and importantly at, say 25 mph off-road. That is low-pressure washboard territory. I’m not too worried about the F rated tires but the E rated tires, yes. In case of a flat they should all be interchangeable. Opinions please.

Which tires are noisy? The MT's?

 

[mrfoamy]

I'm not making any recommendation. I have no idea what your truck weighs.

You can make a graph using the load capaicty and max inflation pressure on the tires sidewall to give you a safe inflation pressure (0 psi = 0 load, max psi = max load). The Toyo stuff should already have the number in it but you have to know what the vehicle weighs. Don't make a rats ass if it's a F-350 or a Yugo, inflation pressure is based off of load capacity and weight.

My recommendation on not mixing tire types front to back is based on personal experience (due to lack of working capital rather than choice; I choose not to walk) as well as the fact (yes fact, not opinion) that it looks ghey.

If you want someone to tell you what pressures to run post the following:

• Tire rated max load capacity (found on sidewall)
• Tire rated max pressure (also found on sidewall)
• Front and rear axle weights of your truck loaded as you normally drive it.

That last one you'll have to do some leg work for. Also note that the calculated pressures will only be valid for that particular loaded weight.

I hope you find what you're searching for...

Yes, I asked the wrong question. I should have said "I know I'm supposed to get axle weights at a weigh station when my camper is loaded as intended but I'm so lazy that I am hoping someone has a truck/camper much like mine so they can respond with their experience". I have gotten very lucky here before but I see that I need to take this to a weigh station on the next trip. Thanks everyone for your comments.

 

[Darwin]

The problem is your tires only give their rated load at 80 PSI. You need to look at the inflation tables, type it into google and you can see what the tires are rated for at a given pressure.

Two different tires seems like a bad idea to me.