Maxxis M8008 Purchase Surprise

[barron64]

Well, when you get down to replacing the tires on a 1.5 yr long driveway project, you know you are getting close to completion. Went ahead and bought a set of Maxxis M8008 ST radials from a local dealer to mark that item off the to do list.

I ordered four 225/75-15, "D" load range for my 75 Trade wind to fit on the original slotted alloy's. Of course I could not leave well enough alone and had to shine up those slotted mags a little. It never ends... Anyway, got the tires for $98.25ea and with a discount on labor (mount & balance) plus tax, I was out the door for $444.51. Got home with the tires and realized I had "E" load range tires instead of the "D" I ordered! Guess I have a little extra load capacity now.

I figure my Trade wind will weigh in around 5K loaded which will be only 1250lb/tire. Looking at the Maxxis load /inflation chart I plan on running around 40psi which still gives me 1880lb/tire or max load of 7520. What do you tire experts think? I could drop the pressure some more, say 35psi, and still have 1760lb/tire or 7040lb total. I cannot see the reasoning to inflate to the max of 80psi for a load of 2830lb/tire.

[Inland RV Center, In]

Originally Posted by barron64

Well, when you get down to replacing the tires on a 1.5 yr long driveway project, you know you are getting close to completion. Went ahead and bought a set of Maxxis M8008 ST radials from a local dealer to mark that item off the to do list.

I ordered four 225/75-15, "D" load range for my 75 Trade wind to fit on the original slotted alloy's. Of course I could not leave well enough alone and had to shine up those slotted mags a little. It never ends... Anyway, got the tires for $98.25ea and with a discount on labor (mount & balance) plus tax, I was out the door for $444.51. Got home with the tires and realized I had "E" load range tires instead of the "D" I ordered! Guess I have a little extra load capacity now.

I figure my Trade wind will weigh in around 5K loaded which will be only 1250lb/tire. Looking at the Maxxis load /inflation chart I plan on running around 40psi which still gives me 1880lb/tire or max load of 7520. What do you tire experts think? I could drop the pressure some more, say 35psi, and still have 1760lb/tire or 7040lb total. I cannot see the reasoning to inflate to the max of 80psi for a load of 2830lb/tire.

Tires must be inflated to a certain pressure, so that they wear properly.

Maximum pressure is not good unless the tires are loaded to maximum.

Under as well as over pressure causes poor tire wear.

Andy

[SteveH]

Originally Posted by barron64

Well, when you get down to replacing the tires on a 1.5 yr long driveway project, you know you are getting close to completion. Went ahead and bought a set of Maxxis M8008 ST radials from a local dealer to mark that item off the to do list.

I ordered four 225/75-15, "D" load range for my 75 Trade wind to fit on the original slotted alloy's. Of course I could not leave well enough alone and had to shine up those slotted mags a little. It never ends... Anyway, got the tires for $98.25ea and with a discount on labor (mount & balance) plus tax, I was out the door for $444.51. Got home with the tires and realized I had "E" load range tires instead of the "D" I ordered! Guess I have a little extra load capacity now.

I figure my Trade wind will weigh in around 5K loaded which will be only 1250lb/tire. Looking at the Maxxis load /inflation chart I plan on running around 40psi which still gives me 1880lb/tire or max load of 7520. What do you tire experts think? I could drop the pressure some more, say 35psi, and still have 1760lb/tire or 7040lb total. I cannot see the reasoning to inflate to the max of 80psi for a load of 2830lb/tire.

Just me, but I would not go below 65 pounds air pressure, the recommended max pressure for a load range D tire. It is theorised that most tire failures are caused by too much heat, which underinflation exagerates.

[r carl]

Between 40 and 50 will be just fine.

[TG Twinkie]

I have a '74 Argosy with a GVW of 6200#. I'm running ST load range D style tires with 45# and it works fine for me. Airstreams have a history of not liking a rough ride. To put load range E tires on it inflated to the max would be akin to running steel wheels. Just my 2 cents worth.
I know most tire have a maximum pressure rating along with the weight carrying capacity. I have not seen a minimum "safe" pressure rating. I have found that most tire installers inflate them to the max when you purchase them. They do this because it is unknown to them what weight they will be required to carry. I think it's a liability thing for them.

[barron64]

Looks like 40-50 lbs will probably be plenty adequate for the load carried.

[SteveH]

You may get by running those lower air pressures in Nebraska, and maybe even in Northern Alabama, but I gurantee you those pressures will cause a trailer tire to seperate and blow in the summer heat in Texas running at highway speeds.

You make your choices, and take your chances....

[r carl]

Originally Posted by SteveH

You may get by running those lower air pressures in Nebraska, and maybe even in Northern Alabama, but I gurantee you those pressures will cause a trailer tire to seperate and blow in the summer heat in Texas running at highway speeds.

You make your choices, and take your chances....

He said his tires will see a maximum of 1250 lbs.
According to the Maxxis chart he only needs 25psi!!!
http://www.maxxis.com/Repository/Files/m8008load.pdf

[SteveH]

Originally Posted by r carl

He said his tires will see a maximum of 1250 lbs.
According to the Maxxis chart he only needs 25psi!!!
http://www.maxxis.com/Repository/Files/m8008load.pdf

Yes, and from the chart itself, it says: "
TIRE LOAD LIMITS (LBS) AT VARIOUS COLD INFLATION PRESSURES (PSI)"

If you run trailer tires at or close to their "limits" in the heat we have here, they will not survive.

[JDavid]

I wouldn't go under 60, you will gain a smidgen of ride softness under 60 psi but you will halve (or worse) the thread life of the tires- not to mention the increased hazard of a catastrophic failure. I run "E" rated tires on my truck at 70 psi (unless dragging a heavy load) and got 60K out of the last set.

[r carl]

Originally Posted by SteveH

Yes, and from the chart itself, it says: "
TIRE LOAD LIMITS (LBS) AT VARIOUS COLD INFLATION PRESSURES (PSI)"

Yes it says 25psi cold for a 1435 lbs loaded tire. At 50psi the rated load is 2150 lbs. He is nowhere near his limit. I dont know what temp Maxxis rates their tires but its prolly summertime temps. I know it gets HOT in tex and heat destroyes tires but millions of tires are rolling on your roads everyday and holding up just fine.

[SteveH]

Originally Posted by r carl

Yes it says 25psi cold for a 1435 lbs loaded tire. At 50psi the rated load is 2150 lbs. He is nowhere near his limit. I dont know what temp Maxxis rates their tires but its prolly summertime temps. I know it gets HOT in tex and heat destroyes tires but millions of tires are rolling on your roads everyday and holding up just fine.

You obviously want to argue about this. Run your tires the way you want.

[Ag&Au]

Originally Posted by r carl

Yes it says 25psi cold for a 1435 lbs loaded tire. At 50psi the rated load is 2150 lbs. He is nowhere near his limit. I dont know what temp Maxxis rates their tires but its prolly summertime temps. I know it gets HOT in tex and heat destroyes tires but millions of tires are rolling on your roads everyday and holding up just fine.

As far as I am concerned, you are reading the chart backwards.

It does not say maximum or even recommended pressure at a given load. It say this is the maximum load at the stated pressure. I sure don't want to run my tires at the minimum pressure for that load. This is what you are recommending. For one thing you can not divide the total weight by 4, because there is no realistic way the load is going to be evenly distributed between 4 tires. It just doesn't happen. It will be even more unevenly distributed with the dynamics involved with highway towing.

As long as you don't exceed the maximum inflation rating for the tire, it will be a safe towing situation as long as you don't exceed the max load for each tire. However running at the minimum pressure for the stated load is a very risky situation in my opinion.

Regards,

Ken

[arcamedies]

Originally Posted by barron64

Looks like 40-50 lbs will probably be plenty adequate for the load carried.

Not to soft, not to hard, JUST RIGHT

Max tire pressure is just that, the max for the tire at 75 degrees F, but if you use the max and have half a load the trailer goes boing boing down the road.

Using the minimum just for a lighter weight makes the sidewalls squishy and creates side sway TO SOFT.

I did get into a friends trailer and felt like I was on the concrete he says the tires wear good at 65psi, of course he can't understand why his cabinates look like an earthquake struck them TO HARD.

I run twink's tires at 45-50 on load range D tires at 4000 lbs and when I get in the trailer I feel some jiggle and the sidewalls flex a little JUST RIGHT.

[r carl]

Originally Posted by SteveH

You obviously want to argue about this. Run your tires the way you want.

Evidently you know your right and accusing me of arguing when Im showing you what the factory say's.

[r carl]

Originally Posted by w7ts

As far as I am concerned, you are reading the chart backwards.

It does not say maximum or even recommended pressure at a given load. It say this is the maximum load at the stated pressure. I sure don't want to run my tires at the minimum pressure for that load. This is what you are recommending. For one thing you can not divide the total weight by 4, because there is no realistic way the load is going to be evenly distributed between 4 tires. It just doesn't happen. It will be even more unevenly distributed with the dynamics involved with highway towing.

As long as you don't exceed the maximum inflation rating for the tire, it will be a safe towing situation as long as you don't exceed the max load for each tire. However running at the minimum pressure for the stated load is a very risky situation in my opinion.

Regards,

Ken

I recomended doubling the minimum pressure. His trailer will weigh 5000 lbs fully loaded.

[barron64]

Man, I love all the feedback on this thread! When I bought the trailer last year in Kentucky, it had four 235/70-15 car tires to roll on. Aired them up to 35psi and drove all the way to Alabama with no issues. When I replaced these this week, I noticed the manuf date was 1999!

Has anybody ever used one of those infra-red temp detectors to check tire temp vs pressure vs load after a run down the interstate? It would be interesting to see if someone could put a chart together blending all of these variables. If we had a reccommended temp range for operating temperature from the manuf, guessing maybe around 120 or so, then you could adjust your pressure and speed to stay withen those limits while not overly inflating the tires.

[r carl]

Originally Posted by barron64

Man, I love all the feedback on this thread! When I bought the trailer last year in Kentucky, it had four 235/70-15 car tires to roll on. Aired them up to 35psi and drove all the way to Alabama with no issues. When I replaced these this week, I noticed the manuf date was 1999!

Has anybody ever used one of those infra-red temp detectors to check tire temp vs pressure vs load after a run down the interstate? It would be interesting to see if someone could put a chart together blending all of these variables. If we had a reccommended temp range for operating temperature from the manuf, guessing maybe around 120 or so, then you could adjust your pressure and speed to stay withen those limits while not overly inflating the tires.

Blend in tread wear too, you want wear across the tread even.

[driftless]

It's pretty obvious from the posts on this thread that there are many opinions regarding the original question. From reading lots of other threads and some tire manufacturer's web pages, it seems to me that the basic need to balance the tire/axle/trailer weights and capacities is being overlooked. Specifically, I believe it is recommended by trailer manufacturers and axle manufacturers that you never run tires that have a higher load rating than the axles as it will put too much stress on the axles.

So, adjusting the load rating downward to reduce the load capacity of the tires by reducing air pressure may take the stress off of the axles, but it will most likely result in a reduced wear life for the tires.

IMHO the retailer didn't do you a favor by mounting the LRE tires as they are not "better" tires, they are just "stronger" tires and they are not within the weight parameters for your trailer.