4.80 8 trailer tire pressure

Sammy · 06-16-2018, 03:25 PM

what pressure do folks run their 4.80 8 trailer tires at? The internet is all over the place, 25 up to 65. Single axel single jet ski trailer.

ishoot308 · 06-16-2018, 04:02 PM

Quote:

Originally Posted by Sammy

what pressure do folks run their 4.80 8 trailer tires at? The internet is all over the place, 25 up to 65. Single axel single jet ski trailer.

Look at the sidewall of the tire and run at max pressure rating.

Dan

8gv · 06-16-2018, 09:11 PM

There are different load ranges which require different pressures.

As mentioned above, go by the max # on the sidewall.

I keep mine at 5# below that number.

fatlazyless · 06-17-2018, 05:14 AM

Off topic from tire pressure but still about 4.80-8 tires for trailers:

For what seems like a low price of fifty five dollars, I just got two new 4.80x8", tires and rims, w/5 lug nut holes, mounted with valve stems, on white painted steel rims from walmart.com. Shipping was free, and they came from Ft Myers, Florida in about a week.

The old tires on the jet ski/small sailboat trailer were new in 2003, and had cracks between the tread, plus they usually lose their seal with the rim over the winter so was best to replace.

Yesterday, left the old Carlisle tires and rims at the Meredith transfer station free store, and they drew some immediate attention. Didn't hang around to see if they got taken? One was actually in a lot better shape than the other, but thought it best to replace both tires for low price, $55, because the good one lost its seal over the winter? For five dollars, Buskey's in Ashland resealed it and told me it was no good for highway, and just maybe ok for a slow, short ride to the local boat launch.

One man's trash is another man's treasure ...... or something?

jbolty · 06-17-2018, 07:01 AM

Tire pressure is not critical on such a light trailer so a little under max is ok, but too hard and the tires will bounce off the road.

here's a method jeep guys use and I do with all my vehicles and trailers. Jeeps are a special case because generally they have big tires which are rated for a much heavier vehicle so setting pressure is non standard.

Quote:

You can also “calculate” your tire pressure with the chalk method. This involves coloring a section of your tire with chalk to see how much tread is making contact with the ground. Start by finding a flat road surface. Concrete is actually the best choice, but you can also do this on asphalt. Make a mark with soft chalk that goes all the way across your tread. Then, gradually drive your truck forward about 50 feet and then backwards 50 feet.

Analyze the chalk on the tire. If the chalk is only worn off on the center of the tire, reduce the tire pressure slightly and go through the process again. With the adjustment, you should see the chalk wear off more broadly. Keep making tiny adjustments in the tire pressure until the chalk wears off evenly and all the way across the tread.

You will have to complete this process for each of your four tires. Once you’ve found the right street pressure, add 10% to all four tires. Then, measure the tires and add pressure to balance them. As explained above, you need to measure from the wheel to the ground. Start by balancing the profiles of the front tires with each other. Then, balance the front tires again with the rear tires. Always adjust the tires with the smaller profiles by adding air.

also, FLA is off topic but still good advice. You don't think about trailer tires because they don't wear much but before you know it they are 10 years old. The sun is the enemy and tire covers will add many years of life . Getting them off the ground sitting over the winter helps too.

Dave R · 06-18-2018, 07:17 AM

I tow my boat all over the place, all the time and have learned a lot through trial and error.

The pressure totally depends on the load. Look at the max pressure and max load rating on the tires, then do the math to see how they should be set for your typical load, and add 10 to 20% for longer tire life.

So if the tires are rated to carry 2000 lbs (1000 lbs per tire) at 40 psi and you are carrying 1500 lbs: 1500/2000*40*1.1= 33 psi or 1500/2000*40*1.2= 36 psi. Thus 33 to 36 psi will be good for the tires and load in my hypothetical example.

If you are at maximum load for the tires (really common with "factory" boat trailers that are built to a price-point and often barely adequate when the boat is empty) I recommend running them at 20% more than the max pressure printed on the sidewall. It sounds like it would be bad for the tires, but it's actually easier on them because they will flex less and run cooler. Have a spare or two and plan to replace them every 5 years or less if this is your situation and you tow often.

06-16-2018, 03:25 PM	#1
Sammy Senior Member Join Date: Sep 2004 Posts: 73 Thanks: 0 Thanked 4 Times in 3 Posts	4.80 8 trailer tire pressure what pressure do folks run their 4.80 8 trailer tires at? The internet is all over the place, 25 up to 65. Single axel single jet ski trailer.

06-17-2018, 05:14 AM	#4
fatlazyless Senior Member Join Date: Apr 2004 Posts: 8,525 Blog Entries: 1 Thanks: 295 Thanked 957 Times in 698 Posts	4.80-8"on five hole rims Off topic from tire pressure but still about 4.80-8 tires for trailers: For what seems like a low price of fifty five dollars, I just got two new 4.80x8", tires and rims, w/5 lug nut holes, mounted with valve stems, on white painted steel rims from walmart.com. Shipping was free, and they came from Ft Myers, Florida in about a week. The old tires on the jet ski/small sailboat trailer were new in 2003, and had cracks between the tread, plus they usually lose their seal with the rim over the winter so was best to replace. Yesterday, left the old Carlisle tires and rims at the Meredith transfer station free store, and they drew some immediate attention. Didn't hang around to see if they got taken? One was actually in a lot better shape than the other, but thought it best to replace both tires for low price, $55, because the good one lost its seal over the winter? For five dollars, Buskey's in Ashland resealed it and told me it was no good for highway, and just maybe ok for a slow, short ride to the local boat launch. One man's trash is another man's treasure ...... or something? __________________ ... down and out, liv'n that Walmart side of the lake! Last edited by fatlazyless; 06-17-2018 at 07:25 AM.

06-16-2018, 09:11 PM	#3
8gv Senior Member Join Date: Jan 2012 Posts: 2,009 Thanks: 61 Thanked 701 Times in 455 Posts	There are different load ranges which require different pressures. As mentioned above, go by the max # on the sidewall. I keep mine at 5# below that number.

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06-18-2018, 07:17 AM	#6
Dave R Senior Member Join Date: Jul 2004 Posts: 2,974 Thanks: 246 Thanked 736 Times in 438 Posts	I tow my boat all over the place, all the time and have learned a lot through trial and error. The pressure totally depends on the load. Look at the max pressure and max load rating on the tires, then do the math to see how they should be set for your typical load, and add 10 to 20% for longer tire life. So if the tires are rated to carry 2000 lbs (1000 lbs per tire) at 40 psi and you are carrying 1500 lbs: 1500/2000401.1= 33 psi or 1500/2000401.2= 36 psi. Thus 33 to 36 psi will be good for the tires and load in my hypothetical example. If you are at maximum load for the tires (really common with "factory" boat trailers that are built to a price-point and often barely adequate when the boat is empty) I recommend running them at 20% more than the max pressure printed on the sidewall. It sounds like it would be bad for the tires, but it's actually easier on them because they will flex less and run cooler. Have a spare or two and plan to replace them every 5 years or less if this is your situation and you tow often.