| |
Subject |
Author |
Date Posted |
Forum
|
 |
RE: 2023 Super Duty 6.7PSD HO Review
Looks like Ford quietly implemented a ninth injector for the regen process and now has a 15k mile OCI for the '23 Power Strokes.OCI ???
|
Huntindog
|
06/05/23 02:01pm |
Tow Vehicles
|
|
RE: Tire Advice
09/22/09 09:22pm Link | Print | Notify Moderator
This post is an open letter to the RV.net community whom have been following the ongoing tire discussions.
I have been following these discussions, but until lately I have been staying on the sidelines until the topic took a turn to a more factual basis. I have personally experienced multiple failures with my 5th wheel and ST tires, both D and E load range and would like to understand why this appears to happen more often with ST (special trailer) vs. LT (light truck) tires. (Based on this forum it must be considered anecdotal and not conclusive evidence.)
To resolve this matter I have investigated the current Federal Motor Carrier Safety Administration (FMCSA) testing standards that ST and LT tires must meet to be certified to be sold in the United States.
First I have some folks that I would like to thank for providing me the desire to delve into this issue:
“Chris” for moving the topic in a more factual direction.
“Tireman9” for helping me find the federal standards.
“FastEagle” for his willingness to challenge group thought and to encourage me to understand the perceived performance discrepancies between these types of tires.
Thanks guys!
For those of you who just wish to get the big picture facts, I have started with a summary section. This hits all the high points and you my quit after reading this. (No need to read all the details if you don’t want to!)
If you wish to understand my research in greater depth (and verify my findings and conclusions), after the summary I have provided the following sections: references, notes, and testing of (1) bead unseating resistance, (2) strength, (3) endurance, and (4) high speed performance.
SUMMARY OF FINDINGS & CONCLUSIONS
I found the testing requirements for both the ST and LT tires at the Federal Motor Carrier Safety Administration (FMCSA) webpage.
The testing for each tire is comprised of (1) bead unseating resistance, (2) strength, (3) endurance, and (4) high speed performance.
The testing for (1) bead unseating resistance and (2) strength were identical for tires representative of moderate to heavy 5th wheels and thus no advantage is given to either tire type.
The testing for (3) endurance was found to be significantly different between the ST and LT tires.
Both the ST and LT are put through the same initial pressure, time and load profile. The total profile lasts 34 hours of continuous run time starting at 85% of rated load and ending at 100% of rated load. To further stress the tires, a load range E tire (nominal 80 psi rating) is tested at a reduced pressure of 60 psi to induce additional load on the tire during testing. (This is reasonable that testing should be conservative.)
But now the endurance testing diverges significantly.
The ST tire is tested at this pressure, time and load profile at 50 mph. After that, the ST test is over.
The LT tire is tested at this pressure, time and load profile at 75 mph. This is a 50% increase over the ST and will induce significant additional load and heating on the tire during testing. After that, the LT test is not complete. Next a “Low Inflation Pressure Performance” test is performed for the LT tire only. The tire pressure is decreased to 46 psi and the tire is immediately run for an additional 2 hours at 75 mph and 100% of rated load.
Thus, the LT tire endurance test is drastically more intense than the ST endurance test.
The testing for (4) high speed performance.
The difference in high speed performance testing between a ST and LT tire is significant. Both tires are tested through a 90 minute speed/time profile.
The ST tire is tested 88% of rated load while the LT tire is tested at 85% of rated load. Thus, the loading is 3% higher based on rated load and this slight advantage goes to the ST tire.
However, the LT tire is tested at significantly higher velocities when compared to a ST tire (99 vs. 85 mph maximum speed). This is a 16% advantage to the LT tire.
Thus, again the overall test for the LT is more rigorous than the ST test.
Conclusion:
It is reasonable to conclude that these test requirements force the tire manufacturer to construct an LT tire more substantially than an ST tire. This is also a reasonable explanation for the same size LT tire is rated at a slightly lower maximum load than a ST tire.
And now, for those of you who need to know all the details, read on!
REFERENCES
The references for my evaluation may be found at the Federal Motor Carrier Safety Administration (FMCSA) webpage:
ST tire standard may be found at FMCSA Part 571, subsection 109.
http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?chunkKey=090163348008f295
LT tire standard may be found at FMCSA Part 571, subsection 139.
http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?chunkkey=090163348008f2a9
Part 571, subsection 139 references Part 571 subsection 119 which can be found at:
http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?chunkKey=090163348008f29d
QUICK NOTES
Each standard for the ST and LT tires has definitions, significant constraints on labeling, etc. that I will not address. There are also tire conditioning (temperature), tire break in, etc. that are the same or similar for ST and LT that I will not address. The details are in the references.
The (3) endurance, and (4) high speed performance tests must not result in tire failure. Tire failure includes visual evidence of tread, sidewall, ply, cord, inner liner, or bead separation, chunking, broken cords, cracking, or open splices, not just a blowout.
TESTING - BEAD UNSEATING RESISTANCE
ST Tire: (reference paragraph S5.2.2)
The tire is mounted horizontally and a vertical load is applied to the tire’s outer sidewall at a rate of 50 mm (2 inches) per minute.
Increase the load until the bead unseats or a specified value is reached.
Repeat the test at least four places equally spaced around the tire circumference.
LT Tire:
Paragraph “S6.6 Tubeless tire bead unseating resistance” references the ST tire procedure noted above.
Conclusion:
The testing for bead unseating resistance is identical for a ST and LT tire.
TESTING - STRENGTH
ST Tire: (reference paragraph S5.3.2.1)
Force a 19 mm (3?4 inch) diameter cylindrical steel plunger with a hemispherical end perpendicularly into the tread rib as near to the centerline as possible, avoiding penetration into the tread groove, at the rate of 50 mm (2 inches) per minute.
Compute the breaking energy for each test point by means of a provided formula.
LT Tire: (reference paragraph S6.5.2)
Each tire shall comply with the requirements of S7.3 of 571.119, which is tires for vehicles weighing 10,000 lb or more. Per S7.3 of 571.119 for our example tire, the testing is the same as the ST tire procedure noted above.
Conclusion:
The testing for strength is identical for a ST and LT tire.
TESTING - ENDURANCE
The following is for a ST or LT tire of less than nominal cross section less than or equal to 295 mm (11.5 inches) which is typical of a 5th wheel application.
ST tire: (reference paragraph S5.4.2)
There are specifications for the contact of the tire mounted on a test axle and steel test wheel after the test that I will not address because they are similar for the ST and LT.
Inflate a load range E to 60 psi. (410 kPa)
Conduct the test at 80 kilometers per hour (km/h)(50 miles per hour) in accordance with the following schedule without pressure adjustment or other interruptions:
The loads for the following periods are the specified percentage of the maximum load rating marked on the tire sidewall:
Time and Percent of rated load
4 hours, 85%
6 hours, 90%
24 hours, 100%
LT Tire: (reference paragraph S6.3.1.2)
“Conduct the test, without interruptions, at the test speed of not less than 120 km/h…” (75 mph)
Inflate a load range E to 60 psi. (410 kPa)
This test uses the same profile as the ST tire.
Immediately following the above sequence perform a Low Inflation Pressure Performance test (reference paragraph S6.4):
This test uses the same tire/wheel as the previous sequence at a reduced pressure.
For a load range E tire the pressure is reduced to 46 psi. (320 kPa)
The same tire/wheel is run an additional 2 hours at the reduced pressure at a speed of 75 mph and 100% of rated load.
Conclusion:
The difference in endurance testing between a ST and LT tire is significant. Both tires are tested through a equivalent loading/time profile. However, the LT tire is tested at this profile at a higher speed (75 vs. 50 mph) and must still endure an additional 2 hour low pressure test without failure. Thus the overall test for the LT is far more rigorous than the ST test.
TESTING - HIGH SPEED PERFORMANCE
ST tire: (reference paragraph S5.5.4)
Load the tire to 88 percent of the tire’s maximum load rating as marked on the tire sidewall. Inflate to 72 psi (500 kPa). Run the test sequentially without interruption at:
75 mph (121 km/h) for 30 minutes
80 mph (129 km/h) for 30 minutes
85 mph (137 km/h) for 30 minutes
LT Tire: (reference paragraph S6.2.1.2.7)
Load the tire to 85 percent of the tire’s maximum load rating as marked on the tire sidewall. Inflate to 72 psi (500 kPa). Run the test sequentially without interruption at:
87 mph (140 km/h) for 30 minutes
93 mph (150 km/h) for 30 minutes
99 mph (160 km/h) for 30 minutes
Conclusion:
The difference in high speed performance testing between a ST and LT tire is significant. Both tires are tested through a speed/time profile. The ST tire is tested 88% of rated load while the LT tire is tested at 85% of rated load. Thus, the loading is 3% higher based on rated load and this slight advantage goes to the ST tire. However, the LT tire is tested at significantly higher velocities (nearly 100 mph!) when compared to a ST tire. This is a 16% advantage to the LT tire. Thus, again the overall test for the LT is more rigorous than the ST test.
* This post was edited 09/23/09 04:30pm by SeniorGNC *
|
Huntindog
|
06/04/23 08:18pm |
Travel Trailers
|
|
RE: Tire Advice
Hi,
I recently had a blowout on my 2009 Skyline Layton 2970 TT (8,800 GVWR). Bought it used late last year, great shape, with Goodyears (including spare) on it that also looked in good shape and that I understand were about 3 yrs old. Tread-wise they have at least another year to them, and since I am on a bit of a budget, I could just put the current spare into use and get a new spare. However, even being Goodyears, with the blowout I'm not sure I trust the rest and would rather buy 4 new.
I know how most feel about "china-bombs", but I am on a budget so can't go with the Maxxis or Sailuns everyone raves about. Plus I'm not convinced its as big of a problem as its made out to be (my old TT had Greenballs and then HiRuns, never had a blowout until the Goodyears). So anyway, I have narrowed it down to the following tires (ST225/75R15):
Power King Towmax Vanguard - Load Index 117, Load Range E, Speed N
Trailer King RST - Load Index 117, Load Range E, Speed M
Gladiator QR25-TS - Load Index 117, Load Range E, Speed N
Carlisle Radial Trail HD - Load Index 113, Load Range D, Speed M
Now I know Carlisle is the only one of these brands that seems to be acceptable by many, and it is only about $10-15 more per tire than the others, but it does have lower load and speed specs than the others. The Carlisle specs are sufficient for my TT weight, but I am wondering if getting more load buffer with the 117/E tires might be better, despite those tires being held in less regard.
Looking forward to opinions! Thanks!
Do whatever it takes to get quality tires on it. This means LT tires. ST tires are all junk. The gov. testing standards for them are a joke. They have much lower standards because they are not rated for passenger vehicle use.
|
Huntindog
|
06/04/23 03:38pm |
Travel Trailers
|
|
RE: Thoughts on a plug-in hybrid conversion
Do not let the contrairians disuade you.
There are some people that cannot even agree on what color the sky is.
Your product is not for me, but it could work well for others. Will you be sucessful? Who knows. But you gotta be, "the man in the arena" to have a shot at it. Herman Lay started out in his garage...turning the lowley potato into a salty snack. Potato chips are in just about everyones homes now. Ray crock had a dream. McDonalds is just about everywhere now. More recently we have Apple. Each of these one time startups took a chance, and changed the world... And made a few bucks while doing so. I wish you well.
|
Huntindog
|
06/04/23 05:16am |
Tow Vehicles
|
|
RE: Is it better to be hooked to short power in storage? or not?
It depends on your converter and your climate.
If you have the notorious WFCO converter that doesn't like to change modes and are in a hot climate, you will likely fry the batteries.I am in Phoenix, and that was my experience. My WFCO was stucck at 13.6, and that was too high here. I changed the converter to a Boondocker, and it worked fine. Some people in cooler climates have reported that the WFCO works fine for them.
FWIW, I have a collectible car in my garage that rarely gets driven.I have a battery tender brand charger on it. That works fine. That battery lasts more than 10 years. The cheaper tenders do not work as well.
|
Huntindog
|
05/31/23 04:13am |
Travel Trailers
|
|
RE: Selling my trailer...where to list?
Going to sell our travel trailer, since we have bought a vacation condo and no longer need the trailer. Looking for suggestions as to where to list the sale? also has anyone delt with POP RV? They talk a good game but are the as good as they say?I have sold all 3 of mine fast and easy on Craigs list.It is free. I will say that the last one got a not of scammers and low baller calls. Just don't fall for them. A true buyer will not try to purchase it over the phone.
|
Huntindog
|
05/27/23 06:04pm |
Travel Trailers
|
|
RE: '21 RAM Big Horn 3500 DRW CC/LB 4x4 with NEXEN Tire WOES!
Both OEM NEXEN front tires (LT235/80R17E) had to be replaced last week due to separation with only 11K miles since I purchased the truck FEB-21. Wish I had known (or researched) these POS tires before I signed on the dotted line or I would have insisted on Michelin Defenders I have always used in the past before I left the dealership. My bad...
I have ZERO trust/faith in these NEXEN tires. Therefore, I am going to remove/replace these crappy tires this week. My problem is finding a Michelin Defender LTX M/S or Michelin LTX M/S2 in my OEM size tires (LT235/80R17E). Only Michelin tires I can find in my size are the LTX A/T2, Energy Saver, and Agillis???, none of which I really want to pay $2K for. I NEVER had so much as a flat tire in the the 20+ years I rode on Michelin Defender LT tires hauling RVs around the USA!
Is there another SIZE TIRE that will fit on my 17" wheels so I can try and find a Michelin Defender LTX or LTX M/S set of tires? If not, looks like I will be buying new wheels also...
Thanks in advance.
Jack in North Florida, Retired
River Life on the beautiful Suwannee River
2021 RAM Big Horn 3500 DRW CC/LB 4x4
2021 Keystone Cougar Half-Ton 29RKSIf you are thinking of 16" rims, that may not be possible. In at least some cases the larger rims are needed for the larger brakes. No ideas if this applies in your case. Just something to check on.
|
Huntindog
|
05/24/23 05:37pm |
Tow Vehicles
|
|
RE: Help me with current best manufacturers
I looked at a 2021 Grand Design TT and it had OEM installed Lionshead Castlerock China Bombs.If the only thing I did not like about a TT was the tires, I would buy it.
It is literally the easist thing to fix. One could take care of that on the way home from the dealer.
Well that's obvious but when an RV manufacturer decides to install the cheapest borderline tires they can find, and tires are in a location that can easily be seen just by walking up to it, I find it hard to believe they don't also use the cheapest borderline other components and materials in places not easily seen. The Grand stops with the name. There is nothing Grand about them and no better than trailers made by others like Forest River or Thor. If it makes you feel better to believe they're that "Grand", and you somehow purchased a peach that is better than A or B, more power to you but it's only a fantasy.I seem to have overlooked your all knowing recomendations. Fact is you have not made any. All you have is trash other peoples opinions. As soon as I finish this post I will block you. I encourage others to do the same. With no audience you will soon go away from boredum.
|
Huntindog
|
05/21/23 05:23pm |
Travel Trailers
|
|
RE: Rain bow
Both of them have 4 tires on the ground and a nut behind the wheel.
|
Huntindog
|
05/19/23 01:56pm |
Around the Campfire
|
|
RE: No more training wheels
It settles 2 1/4” with the RV on the truck. It is enough that some oncoming drivers were flashing their lights. Would have got the air suspension if I ordered the truck.
Bigger tires are for aesthetics. They won’t be huge but I’ve never been a fan of stock size.
You want the truck to set "LEVEL" and ride on the overloads. Yes I get flashed at times but oh well! I set 55" top rear bed to ground with factory rear air. LOVE it!!!Headlights are adjustable to fix this.
|
Huntindog
|
05/16/23 09:15pm |
Tow Vehicles
|
|
RE: No more training wheels
It settles 2 1/4” with the RV on the truck. It is enough that some oncoming drivers were flashing their lights. Would have got the air suspension if I ordered the truck.
Bigger tires are for aesthetics. They won’t be huge but I’ve never been a fan of stock size.Bigger tires on a TV effectively lowers it's rating and performance as a TV. How much is debatable. but it definantly will not help it.
|
Huntindog
|
05/16/23 09:12pm |
Tow Vehicles
|
|
RE: 2023 Super Duty 6.7PSD HO Review
Telescoping wheel would be nice but for me in my RAM not really needed. No way on the heads up display, drove a Mercedes with it and hated it.
If I turned my steering wheel as much as he did I would be in the next lane as my steering is that tight.
Nice truck but not worth the $$$ IMHO.
Oil and fuel filter access is good but that hose monster is a "NO BUENO" for me. I will tale a couple minutes longer to change the filters for having my engine actually visible. I have the HUD on my Silverado, and never want a truck without it.It was invented for fighter planes, so they could see what they needed to without looking down. best thing since sliced bread.
I get that but they keep making the info screen larger that you DO have to look at to change anything. I think a lot more can happen quickly in a Jet.
You have not seen me drive!!!!:B
|
Huntindog
|
05/15/23 11:02am |
Tow Vehicles
|
|
RE: Used Nash TT 22H model, any good? What's it worth and...
You said,"I do not yet have a brake controller or a distribution hitch. I need recommendations for these.
I will have to drive it home under standard towing set up, about 60 miles in fast moving, heavy traffic, mostly level with a few small hills, to get it home. Once home it will sit until I can get it cleaned up and set up the way my wife and I want it. I will then install a brake controller and buy a distribution hitch."
Dont take it on the road at all without a brake controller installed! You will be breaking the law and putting yourself and others in danger.
The Tekonsha Prodigy P3 brake controller are plug and play because it comes with the wiring harness for your truck from that retailer. Note: Don't try and save a few bucks by getting a "time delay" controller.
One more comment. You will most likely be at the limit of your truck with that trailer. I would not pull it without a WD hitch. They are not very expensive and also very easy to install. Get one like this and be safe - at least equipment wise. Good luck and I hope you enjoy your trailer.:)
Barney
Thanks! Ok, so I'll get the brake controller done, and buy the WD hitch before I get the TT. Actually, IF I get this one. The seller is already telling tales.What do you mean by "telling tales?
From what you have posted, it sounds like a good deal. Check out the roof. If that is good, buy it. Lots of used junk out there in that price point.
|
Huntindog
|
05/15/23 06:07am |
Travel Trailers
|
|
RE: Help me with current best manufacturers
I looked at a 2021 Grand Design TT and it had OEM installed Lionshead Castlerock China Bombs.If the only thing I did not like about a TT was the tires, I would buy it.
It is literally the easist thing to fix. One could take care of that on the way home from the dealer.
|
Huntindog
|
05/14/23 09:43am |
Travel Trailers
|
|
RE: Help me with current best manufacturers
My Momentum has optional 8K axles and disc brakes, 17.5 LRH tires, a 12" tall frame, and is the first RV I have owned where the tanks actually hold what they are spec'ed at. This is my 4th RV over 30 years, and the best one yet.
Thats great, but I am not sure what the height of the frame has to do with quality. One would expect the frame rails to be larger on a bigger rig. A 12" high frame can be fabricated just as shoddy as a 6" high frame and when it comes to LCI that speaks for itself. I've yet to see a quality weld on an LCI frame and its a known fact they use cheap surplus steel whenever they can and the smallest/lightest they can get away with. You paid for the optional axles and disc brakes, what would you have gotten from Grand Design as "stock"? Are you saying that the stock axles and brakes are low quality? I looked at a 2021 Grand Design TT and it had OEM installed Lionshead Castlerock China Bombs.GD uses Dexter axles with self adjusting brakes. In the 2021 model year they were 7K axles on the big Momentums with an option for 8K with disc brakes and Cooper 17.5 LRH tires. Triple 7Ks had a GVW of 20K and Triple 8Ks bumped that up to 21K. The pin box is/was the limiting factor. Now they are coming With the 8K axles/disc/LRH tires standard. This puts the GD toyhaulers far ahead of the competition.
If you will notice even the 7K axles in 2021 exceeded the GVW of 20K...A stark contrast to the industry standard of subtracting the hitch weight from the GVW to determine axle size.
A testament to GDs confidence in their frame and running gear is that they state the garage can have the entire CC loaded into the garage! My Momentum 398M has a CC approaching 5K!! I have a trip planned where I will load a Jeep into the garage. That would not be possible within the ratings of most of the competition
I haven't been shopping since I bought my Momentum, but at that time, they stood out from the rest. Only DRV, Luxe, and New Horizons were better in some areas. But none of them had the 18' garage we needed
|
Huntindog
|
05/14/23 05:53am |
Travel Trailers
|
|
RE: Ram Cummins/Aisin Failures
Meanwhile, at the Ford dealership down the street, the mechanic has nothing to do. He and the Maytag repairman knock off early to drown their sorrows at the local tavern, and tell each other that something will break soon.:B
|
Huntindog
|
05/12/23 05:47pm |
Tow Vehicles
|
|
RE: Backwards buttons
I think you’re exactly right, as when I disconnected the battery, replaced the fuses, and powered back up, all was good.
Now to figure out how I messed that up. I’ve only done this how many times before…You probably blew the fuses on the convertor. There is ususally 4 of them IIRC. They are there just for when the battery is hooked up backwards. To prevent future brain farts, only dissconect 1 battery cable.
|
Huntindog
|
05/12/23 04:29pm |
Travel Trailers
|
|
RE: 2023 Super Duty 6.7PSD HO Review
Telescoping wheel would be nice but for me in my RAM not really needed. No way on the heads up display, drove a Mercedes with it and hated it.
If I turned my steering wheel as much as he did I would be in the next lane as my steering is that tight.
Nice truck but not worth the $$$ IMHO.
Oil and fuel filter access is good but that hose monster is a "NO BUENO" for me. I will tale a couple minutes longer to change the filters for having my engine actually visible. I have the HUD on my Silverado, and never want a truck without it.It was invented for fighter planes, so they could see what they needed to without looking down. best thing since sliced bread.
|
Huntindog
|
05/11/23 05:09pm |
Tow Vehicles
|
|
RE: Help me with current best manufacturers
Just Bought a New 20 ft Grand Design. Don't do it! The enginering isn't the Best is an Understatement. and out the Door Quality??? Rust? Door that won't open? Etc...
Focus on what is important.
The foundation IE, The frame axles and tanks. GD tends to have more robust items, an even has axle/tire/brake upgrades avaiable on some models. I have read good things about Northwoods and outdoors as well.
Interesting. I am not sure what Grand Design has that would qualify as "more robust items". From what I have seen and researched they use just as much cheap junk obtained from Lippert as Forest River and Thor, perhaps more, from the frame on up. A couple oif years ago they had Lippert running gear failing in a big way. A close friend bought a Solitude 5th wheel which had so many recurring issues he dumped it after a year and a half.
Grand Design was started by 3 guys who spent their life in the RV Industry, mostly with Thor/Keystone/Dutchmen RV, who were/are known for the highest level of quality LOL. They blew a lot of smoke, built up a cult like following the first few years, then cashed out and sold out to Winnebago. One stayed at Winnebago as Pres of the Grand Design Division, the other two now have started another company to fleece more people with slapped together junk. All of the original hoopla over higher quality and better customer service went out the window over time. Grand Design is no better than any other of the mass produced brands.My Momentum has optional 8K axles and disc brakes, 17.5 LRH tires, a 12" tall frame, and is the first RV I have owned where the tanks actually hold what they are spec'ed at. This is my 4th RV over 30 years, and the best one yet.
|
Huntindog
|
05/11/23 03:07pm |
Travel Trailers
|
|
RE: I Bought Too Much Truck
HA! And I know this is no bs since I saw your video of backing a GN trailer at what like 30mph?
Fwiw I tried. Although with a long bumper pull flatbed. My personal best was only a bit over 15mph before I chickened out or things got squirrelly! Lol
Not that any of the last couple pages has to go with Steve and his truck….
I should have made a better quality video while I had the chance. I was able to hit 35 mph backing the gooseneck with my 2017 F350 but Ford has spoiled my fun. The new 10 speed with its 4.92:1 reverse gear ratio and rev limiter has been neutered so as to have a top speed of 20 mph in reverse.Awww shucks. I was looking forwards to a "Hold my beer and watch this" video:B
|
Huntindog
|
05/09/23 04:36pm |
Tow Vehicles
|
|
