This makes for some interesting comments ,I found this in my manual the same thing a Bridgestone and Toyo rep told me,I will snap you a photo of the "caution" when my battery get charged
So Clifford, does this disqualify the guys that measure each wheels recomindations for ride comfort? lvmci...
For comparison's sake, what does your sticker read and how does it compare to what the tire manufacturer's chart?
Never had any tire stickers on our 4104, nothing in da book either.
I've got the book for my 4108, and it shows pressures that are lower than the chart from the tire company. Since the chart for my bus was designed for use with bias tires with a G load rating, I ignore them and go with the tire company chart.
That states Medium Duty Trck tires. Not H rated 16 ply which are heavy duty?
Quote from: Dave5Cs on December 28, 2019, 07:04:44 PM
That states Medium Duty Trck tires. Not H rated 16 ply which are heavy duty?
It says buses too now are we driving a bus or a RV,the rating of plys means a tire can carry more load with more air pressure or it did.Now on the serious side, Dave are you and Doreen going to Quartzsite this year Sonja would like to see Doreen
If Publishers clearing house check comes Monday we will go. But probably not this year.
We have got to that stage of old where if you sit down and take it easy you will pay, LOL
Sent you a PM
I think that is covering school type busses, not coaches, which are not considered medium duty, which school busses and motor homes are.
Need to see if new Prevosts or MCI's use this type of tire label.
Quote from: chessie4905 on December 28, 2019, 07:37:09 PM
I think that is covering school type busses, not coaches, which are not considered medium duty, which school busses and motor homes are.
Need to see if new Prevosts or MCI's use this type of tire label.
My MCI DL3 has a tire label the CC has a label even for load index,I am at 52,000 lbs GVW and 61,000 lbs axle weight is that medium or heavy ?
That's why I asked about new coaches, whether they have them or not. Maybe it is only on medium duty and any newer motorhomes regardless of weight.
Quote from: chessie4905 on December 29, 2019, 04:55:22 AM
That's why I asked about new coaches, whether they have them or not. Maybe it is only on medium duty and any newer motorhomes regardless of weight.
I always thought the TPM on the newer buses were just a option then I found they are required by law just like they are on cars and pickups,LOL makes you wonder if they are sending a electronic message to big brother via Google
All kinds of regulations on everything just keep spreading year after year.
When the officials refer to "medium duty" tires, they mean bus and truck tires that we are familiar with.
"Heavy duty" tires are not found on road going vehicles.
These general classifications cover the entire range of "tires" and can cause confusion outside of the learned circles of lab coat and pocket protector wearers.
I smell your American lawyers unwashed hands all over this, and it hav ing little to nothing to do with the inflation any particular tire should have in it...
Happy coaching!
Buswarrior
Quote from: buswarrior on December 29, 2019, 05:47:52 AM
When the officials refer to "medium duty" tires, they mean bus and truck tires that we are familiar with.
"Heavy duty" tires are not found on road going vehicles.
These general classifications cover the entire range of "tires" and can cause confusion outside of the learned circles of lab coat and pocket protector wearers.
I smell your American lawyers unwashed hands all over this, and it hav ing little to nothing to do with the inflation any particular tire should have in it...
Happy coaching!
Buswarrior
Sure it is the tire manufactures don't care what pressure you run,they are not taking blame if a tire fails and causes a accident if not inflated to the standard axle limit inflation ,another Ford/ Firestone deal not going to happen again costing billions of dollars the got you in wording took care of that.The tire industry is big business and you play their game lol now you changing tires every 6 or 7 years instead of 15 years like in the past they doubled their sales making a cheaper tire and selling at a higher price JMO
Face it. This country is run by lawyers. You notice politicians don't attack the legal profession, there is no regulation on them."You don't pay unless we win"), they typically get 30 to 50 percent of the proceeds of a winning lawsuit. They are advertising everywhere on tv anymore. Class action lawsuits on drugs, cars, toys, food, medical mail practice, hospitals, etc,etc.
Their time will eventually come. This is not to say many suits have been beneficial over the years. Notice how many Senators and Representatives are from or go to the legal profession when they retire.
Well, all the politicians are lawyers anyway.
To be fair, some of the politicians are doctors, farmers, and at least one bar maid. The vast majority are lawyers, though, and it always seemed to me that it was a conflict of interest for lawyers to pass laws that they would benefit from when in law practice. This whole tire inflation level thing sounds like an attempt for tire companies to avoid litigation when one of their tires cause an accident. That is why tire pressure sensors are now provided on many cars. It still makes sense to know the weight on each tire position, and adjust the pressure to provide even tire wear with heat levels that will not increase the risk of tire failure.
Quite simply-they are covering their butts. If you run at maximum tire pressure on the side of the tire, you'll have a ride like a fork lift. I still maintain to weigh your bus at the heaviest (everything full) and then consult your manufacturers tire inflation table. Then run about 5psi higher. Good Luck, TomC
Actually, few ever spend the time or money to get their coaches weighed at each corner. Not that it is that expensive either.
Getting it weighed at each corner isn't that accurate since most air ride buses have a single leveling valve in the front that makes for exactly the same weight on the right and left. But on the rear-you could have it heavier on one side or the other. The only real way to find out is to weigh. Good Luck, TomC
Good point Tom on the tripod leveling system. It's sometimes hard to figure but yes the front is equal weight on both sides of the axle.
Not all buses have a front axle,the only way you can balance one with Independent front suspension is weigh both sides,you would be in a world of hurt on a Eagle thinking it would be the same on both sides
Drain the airbags on the front axle to get individual corner weights. Tom, doesn't the air in bags just level the coach? Wouldn't the wheel weight stay the same? I'll have to try that when I get mine weighed.
I am deprived of all airbags, but it seems to me that if the weight on one side of the front suspension is greatly different, and yet the bus is level, there would have to be greater pressure in the airbag on that side to hold it up level. If the pressure could be measured, it should indicate the difference, just as in the case of a hydraulic jack with a oil pressure gauge.
The air in the front suspension (at least on our 4104) is equal on both sides... It has to be. It's one system with no point of separation between the sides. The moment all the air front is exhausted to see what the difference in side by side weight is - the rear weight difference from side to side is being transferred to the front because the cushion of air to enable the whole front to act as one system is gone to independent solid mechanical points on each side.
If that is the case then, it would seem that if the bus were particularly heavy on one side, it would not be level, or is there something else at play?
The rear air suspension is independent on each side with two separate leveling valves. The difference in side to side weight is sensed by only rear leveling valves to compensate so bus is level. The word level is also misleading because it doesn't mean bus body level with ground - it means bus body level with rear axle. If your rear axle is on side to side unlevel ground so will be the body. The front leveling valve (1 common to both sides) will compensate for front to back level between the bus body & front axle - not the ground. We really never had a clear understanding of the tripod system untill we installed manually operated solenoids to level the bus "body" with the ground during parking or camping and that system is only good for a max of almost 4" inches difference across all corners. Think of a 3 legged stool on uneven floor - it won't rock as a 4 legged stool would.
Quote from: dtcerrato on December 30, 2019, 07:58:44 PM
...The word level is also misleading because it doesn't mean bus body level with ground - it means bus body level with rear axle. If your rear axle is on side to side unlevel ground so will be the body. The front leveling valve (1 common to both sides) will compensate for front to back level between the bus body & front axle - not the ground...
What he said.
Substitute the word 'parallel' for level and it makes even more sense.
When we got our first bus it drove me crazy that it looked crooked every time we parked on our driveway, but straightened up once we got on the road. I was expecting the suspension to keep it level, when all the while it was doing its best to keep the body parallel to the rear axle.
The only way the weight could be the same on both sides is if the axle had a pivot point in the center all your front end loaders and rubber tired construction equipment uses the center pivot to achieve that.
I have seen it many times over the years at Marathon,Country Coach and Vogue a Prevost shell setting on 6 scales as they do the conversion process and they pay close attention at the side loading on the front axle.John and Walter have it right
Ride height control valves
Get rid of the word "level" and a bunch of this goes away.
Happy coaching!
Buswarrior
Spring suspension, two valve air ride, torsilastic can be different weight on the front. But a single leveling valve operating both sides of the front axle will net exactly the same weight on both sides, no matter what the rear axle is doing since they are equalizing side to side constantly. Good Luck, TomC
Quote from: TomC on December 31, 2019, 08:31:29 AM
Spring suspension, two valve air ride, torsilastic can be different weight on the front. But a single leveling valve operating both sides of the front axle will net exactly the same weight on both sides, no matter what the rear axle is doing since they are equalizing side to side constantly. Good Luck, TomC
But don't the rear height valves control both the front and rear for each side? So if I put a 1000 generator on the right side, the rear height valves are going to put more air pressure in both right corners, front and rear. The suspension keeps the body parallel to the axles, but there is still more weight on the right side of the bus.
It was explained to me that the front valve only controls the nose up/nose down, and that the rear valves only control side-to-side.
Or am I missing something here?
Someone need to go to the scales that has manual air suspension control and settle this once and for all.
All I know for sure is my DL3 is 217# heavier on the drivers side aired up to the ride height I never checked when not aired up,could be thicker brake shoes on that side what do you think
"But a single leveling valve operating both sides of the front axle will net exactly the same weight on both sides, no matter what the rear axle is doing since they are equalizing side to side constantly. Good Luck, TomC
What Tom said is the way it is. The tripod leveling system on the Monocoupe GMs prevented the "box" from being tweaked. There's no one that I have more respect for than the civilian engineers of post WW era because previously they or someone close to them were probably military hardware engineers. While our bus height is maintained by the original height control valves the box is in static mode - no creeks or noise of any kind. The second the tripod leveling is defeated by manual means and the tripod becomes a quad, the "box" starts talking. The mechanical pivoting axle is exactly what the front one height control valve is doing for the tripod air height control on air spring suspension.
If a scale is showing 217# difference side by side on a front axle with one height control valve - that weight difference is happening below the bottom mounts of all the air springs...
Quote from: dtcerrato on December 31, 2019, 05:31:43 PM
If a scale is showing 217# difference side by side on a front axle with one height control valve - that weight difference is happening below the bottom mounts of all the air springs...
Are you talking about unsprung weight?
I still don't understand why there wouldn't be a different amount of weight pushing down on each side. The air bags on the heavier side will have more air pressure in them, resulting in the body of the bus staying parallel to the axles, but those air bags are still carrying more weight. Therefore the tire is carrying more weight.
If only the rear axle adjusted side-to-side to accommodate a weight imbalance, it would seem that the body of the bus would have to be torqued to keep both ends parallel to their axles on flat ground.
My DL3 has the tripod system like as on any bus,the only thing different in both sides is the steering sector on the drivers side
The fact that there are two height control valves on the rear axle means that each side (2 bags + 2 bags) has independent psi to each pair of bags. The fact that the one height control valve on the front axle means that the front whole air suspension system (all four front air bags) have exactly the same psi in each & every bag so the downward pressure on both sides of the axle are exactly the same - ie: from the bottom support of all four air bags upward. If there is a difference of side by side front axle weight it has to be occuring below the bottom air bag supports...
"The air bags on the heavier side will have more air pressure in them, resulting in the body of the bus staying parallel to the axles, but those air bags are still carrying more weight. Therefore the tire is carrying more weight."
Richard what you stated above in quotes is EXACTLY what is happening on the REAR axle ONLY.
If you put a 2x6 across 2 blocks and stand in the middle the weight would be the same on both blocks right,so what would happen if you moved 2 ft in either direction would it change or not ?
Yes because the longer cantilever would add more weight, :)
You guys keep saying this statement,
"the body of the bus staying parallel to the axles"
Think about that, that does not always happen. You can call it Leveling or ride height but in reality the bus adjusts to ride height or level while moving and unless the road is perfectly level this can not happen....
Unless the body reaches down and pick up the axles, which it does not do so many times there is more measured distance between the body and the axle or less but not also and very rarely parallel.
Quote from: Dave5Cs on December 31, 2019, 07:17:13 PM
You guys keep saying this statement,
"the body of the bus staying parallel to the axles"
Think about that, that does not always happen. You can call it Leveling or ride height but in reality the bus adjusts to ride height or level while moving and unless the road is perfectly level this can not happen....
Unless the body reaches down and pick up the axles, which it does not do so many times there is more measured distance between the body and the axle or less but not also and very rarely parallel.
The way you set the ride height valves is by measuring the gap between the bumper on the body and the axle. The goal is to get it to maintain the same gap on both side. Accomplish that and the body of the bus is parallel to the axle.
Bring the bus to a bus stop and load up with passengers. They all decide to site on one side. The bus wants to go down on that side, causing the ride height valve to put more air in that side to bring it back to the present point. Result is that the body is again level to the axles.
Quote from: dtcerrato on December 31, 2019, 05:58:43 PM
...Richard what you stated above in quotes is EXACTLY what is happening on the REAR axle ONLY.
But it's impossible to disconnect the rear of the bus body from the front. If what you're saying is accurate, then if you add 1,000 pounds to the right front right corner of the bus, the right rear tire will be carrying a bigger load and then left rear, and both of the front will equally share their portion of the new load?
It would seem that this would put a twisting force on the body which would do eventual damage if it was always in such a state.
Air bags replaced leaf springs years ago for cost and comfort that why they are called air springs it is still the same principal when it comes to weight distribution that did not change
There have been systems that calculate the weight of an axle based on air pressure for decades, but they do not indicate the weight at each individual wheel. The only way to achieve that simultaneously is the use of piezoelectric sensors at each wheel, just like Cliff mentioned being used by coach conversion outfits. Most truck scales weigh a pair of wheels on an axle position at a time, and some have rails on the side so that you cannot weigh one side at a time. Regardless of the airbag or torsilastic system in use (or combo), the weight on an individual tire can vary. It seems very prudent to know how much weight is on each tire position for the sake of tire load safety, and evenly applied braking traction. A lightly loaded tag or bogie is going to lock up and slide before the other positions, and an uneven load on the front wheels (and/or uneven tire pressure) might cause pulling to one side in hard braking.
"and an uneven load on the front wheels (and/or uneven tire pressure) might cause pulling to one side in hard braking." I was going to make mention of that yesterday but was already long winded but the "tripod" automatic height control valve set up did away with an uneven load on the front wheels because there isn't one from the lower air spring supports upward. Of coarse like Clifford said stationary weight on the front axle like power units, steering boxes being off centered ie: would differentiate tire load but only from an imbalance of axle mounted equipment and not body load. (all four front air springs constantly maintain equal PSI.
If you read the post people like me are taking Tom as saying the load is going to be same on each side at the wheels he made no mention of the body or I missed it
If you are on a 6% slanted road I guarantee you the body and the axle will not be parallel. The passengers will be over on the other side of the aisle. It is a series of loading and unloading the airbages to keep the body as close to level as they can. The rear are side to side and the front up and down as a tri pod. ;)
Hi All, my tag Toyo's are at 10 years, was going to get Toyo's for the front see if a higher quality tire will ride smoother, but 315s and 12Rs are rated for 65mph, so bit the bullet for Hankook with a 75mph L rating, the Double Coins M rated, are now drives and tags and they never really balanced well. I hope with high speed balance on the Hankooks, will ride smooth all the way to 75mph, lvmci...
I've found quite a few 12R and 315s rated to 75, including Toyo.
Well Richard, there were 5, 315-80 Toyos, 3 rated at 70 and 75 mph, much more expensive, but rated for off pavement and long distance, according to their flyer at Southern Tire, they suggested the Hankook L rated 75mph, so I went for it...
The Hankook is a good tire from what I've read. Since there are a lot of commercial coaches running the 315s, I'm sure there are even more out there than I've seen with the 75 mph rating. You are correct though, they aren't cheap. To replace my Firestone FS400 would require a small mortgage. I'm probably going to go with the FS561 in 12R22.5 in the spring - they are only H rated, but that should be more than enough tire, even with the bus weighing in at 30,000 lbs.
Which Hankook did you go with? I see that their 12R22.5 is only H rated (16 ply), so I'm assuming you went with 315s if you have the L rated.
Both of these show a 9" rim on their charts though, so I'd have a problem since I still have the 8.25" rims.
Cliff-your analogy of the board between to blocks is noble. BUT-blocks are solid whereas air suspension has air lines connecting the two sides to each other. So the two sides are constantly balancing each other out. When you stop and weigh, you'll find that no matter how the bus is sitting, both sides are going to be always equal (with one leveling valve). This is why those bus nuts that have taken off their automatic leveling valves and replaced them with 4 manual valves run the risk of tweaking the body-of which GMC engineers were trying to avoid this with the tri-pod suspension system. My recommendation always to those that have manual leveling valves is to only have one valve for the front axle to maintain what GMC engineers designed into the original buses. Good Luck, TomC
Richard-I just went on the Hankook tire site and it is very incomplete. I have AH37 11R-24.5 on my bus. While they ride just a bit harder then the Michelin XZE2's I took off, $1,500 cheaper for 6 says that I can put up with the harder ride-which now I really don't even notice.
I am normally a Michelin user. But from my days of being a Freightliner new truck engineer and salesman, Freightliner's standard tire is Hankook-unless you order differently. I figure if it is good enough for the biggest truck manufacturer in the US, then they should be good. Just stay away from no brand name Chinese tires! Good Luck, TomC
Tom I totally agree with you, we are on the same wave length pertaining to tripod suspension. It is accurate as Cliff stated that side by side front weight can be different if component placement (steering boxes, power cylinders, etc.) on the front axle are off center & "underneath" the lower air spring supports.
Quote from: TomC on January 11, 2020, 08:46:53 AM
Richard-I just went on the Hankook tire site and it is very incomplete. I have AH37 11R-24.5 on my bus...
I noticed that too, and had to download their spec book to get more details. The book shows the AH37 11R22.5 on 8.25" rims, and shows 12R22.5 on 9" rims. They don't show any other allowable rim widths.
Firestone lists 9" rims for the tires I am looking at (FS561) but in the back of the book where there is more information about rim widths they include 8.25 as well, just not in bold print (bold print must be their recommended width). For the FS400 tires in 315/80R22.5 they list 9" in the back, with a footnote about using on 8.25" with a slightly reduced weight limit.
I would add the Hankook tires to my list of tires to consider if I knew for certain that they are approved for the 8.25" rims in the 12R22.5 size.
With those size tires 3/4" rim difference isn't a cause for concern, unless you are running near maximum rated tire weight.
Quote from: chessie4905 on January 11, 2020, 02:40:41 PM
With those size tires 3/4" rim difference isn't a cause for concern, unless you are running near maximum rated tire weight.
The 315's balloon out on the bottom on a 8.25 wheel on the 9 inch the side walls are more vertical and do carry more weight you really need to be careful running 2-315's together on 8.25 wide rims with low air pressure for the smooth ride they will rub the sidewalls out
this will save you some money
https://us.amazon.com/dp/B07S2MYFQL/ref=psdc_353633011_t2_B00VO345BM
dave
Sledhead-My opinion-that tire is EXACTLY the type of tire you should stay away from. A no name Chinese tire that who knows how it is made? Tires are much more than big black rubber round things that hold air. Who knows the tire compound, the tire construction, etc. Michelin makes 50 different truck and bus tires for specific uses. PLEASE stay with name brand tires! Good Luck, TomC
thanks Tom
I was wondering how long it would take for someone to say something
the price is awesome but who knows about the quality ?
dave
You guys are funny I can remember back in the 70's the exact words were said about the Japanese and Korean made tires 1st came here.DOT sets the standard for tires here I am not saying the Chinese made tires are that great but!!! lol my Michelins are made in Brazil and I know nothing about a tire made in Brazil with a DOT stamp
I agree Clifford the tires on my Jeep are from Indonesia. They are the smoothest tires I have ever ridden on. My Bus has Toyo's and are 6 years old with no problems.
We had Michelin's on our Buick and they were worn out in 2 years and were always hard riding with really smooth side walls.
I'm not sure that the country of manufacture is the issue here, but rather the no name company making them.
With a known company you get a known reputation and known level of quality. Usually.
Where does the no name come from the manufacture of Radar tires sells a lot of tires
Quote from: richard5933 on January 20, 2020, 03:18:37 AM
I'm not sure that the country of manufacture is the issue here, but rather the no name company making them.
With a known company you get a known reputation and known level of quality. Usually.
Lets see do you remember Goodyear and the Ford Exploder. How long did that last before someone feesed up We had a Mercury Mountaineer (Same vehical but mercury)at the time and the tires were replaced after many hours of debate of who's fault was it, We sold the car soon after.
I had Michelin's on the Trek they recalled 1.5 million of those tires all the name brand manufactures have had huge recalls
I thought it was Firestone vs Ford Explorer. Ford specified only something like 22 or 24 lbs of pressure in the tires to provide a nice soft ride. Problems with rollovers from tire failure. Ford said it was all Firestone's fault.
Every company has problems from time to time - that's a given. The difference with a big company is that there is someone there to stand behind the product, or be sued if they don't.
The fact that companies like Michelin and Firestone recall tires means that they are large enough companies to withstand that kind of recall.
I'm not bad mouthing every little company out there, but this thread is the first time I've ever heard of Radar tires. It looks like Radar has been around only since 2006, and they are part of Omni United, which has only been around since 2003. All in all, that's not a long time for a tire company to be around.
Quote from: richard5933 on January 20, 2020, 03:18:37 AM
I'm not sure that the country of manufacture is the issue here, but rather the no name company making them.
With a known company you get a known reputation and known level of quality. Usually.
Good or bad, the reputation of the brand has never been higher for those needing to stay on the side of quality vs price. It is the company behind the brand that is most vested in ensuring products are made to the their quality standard - a key to build and retain long term customers. Stick with US companies and you have a lot more protection than buying direct via alibaba, banggood, aliexpress etc. Virtually, blind faith in the level of the supplier's integrity and honesty.
As I have mentioned before, the real test of the quality of a tire is whether a good re-capper like Bandag will accept it for retreading at all, let alone two times, three times, up to five times (in my experience). The only brand that did that for me was Michelin. The chances of a lesser known Chinese tire being accepted as a retread core are dismal, currently. Maybe some day their quality will rise, but I don't think most of us have enough lifetime left to wait for that. If you younger busnuts use these tires, especially on the front axle, you might not have as long a lifetime as you think, should a sudden blowout happen. We need tires that will last over time, rather than treadlife. If you really want Asian tires, stick with Japanese, Korean, or Vietnamese (surprisingly). :o
Sorry yes it was Firestone and they replaced them with Goodyears but being no one could actually answer the question of who's fault it was for the vehicles flipping over we sold the SUV.
It took many years for the made in Japan lable to become excepted and stil haven't with some people.
Loved my Tacoma and Tundra's and if I till needed a truck that's what we would buy.
You guys do know that a lot of those no-name tires are made by the major manufacturers right? I have no clue why they do it but that's been going on for a long time.
Jim
Quote from: Jim Blackwood on January 22, 2020, 09:29:57 AM
You guys do know that a lot of those no-name tires are made by the major manufacturers right? I have no clue why they do it but that's been going on for a long time.
Jim
Have you got any stats showing which brand goes to which manufacturer?
The Omni United brands seem to be their own work, according to their website.
Michelin and Double Coin have some kind of connection, or did.
Quote from: chessie4905 on January 22, 2020, 11:22:26 AM
Michelin and Double Coin have some kind of connection, or did.
https://www.rubbernews.com/article/20171120/NEWS/171129992/michelin-selling-its-stake-in-double-coin-joint-venture
You never know where a Michelin tire is made unless you read the sidewall,I don't worry to much about it as long as it has the DOT on the sidewall,I have some Continental 295/80/22.5 takeoff in bold letters they say engineered in Germany in the fine print they say made in China
I flat spotted my tag tires being dumb and at that low price delivered I was thinking it might be a good test ? or how much damage can driving with the flat spotted tag tires could do if I drive back home 1600 miles ?
I lost about 3 / 16 of an inch on both
dave
Lots of high-quality items are manufactured in China, but in order for the quality to remain constant it's necessary for the company paying for production to stay on top of supervising the plant and maintaining high standards.
Left alone, many factories will take short cuts and use the least expensive method of production possible. Many of the problems in production can be traced back to things like rejects being thrown back into the raw material hopper rather than being properly recycled, contaminating the next batch. This happens everywhere, not just in China. With a US manufacturing plant though, it's relatively easy for the plant to be supervised. That's not as easy when production is overseas.
I have a friend that works for a high-end HVAC company with production in China. They keep people on site at all times to ensure the specifications are met with every batch/run. Companies that don't do this have problems, but obviously doing this costs money. There's a reason some brands cost more, and part of it is the resources committed to maintaining high standards.
When a company like Michelin, Continental, or Goodyear contract with a production facility in China they send people to watch over things. Their company name and reputation is on the line. I'm not sure if Chinese companies are as focused on maintaining high quality standards, especially the companies that come and go or change ownership/names regularly.
I wouldn't trust a DOT mark on the sidewall to guarantee quality. Unless I'm missing something, don't companies self-certify that their tires meet DOT guidelines? I can't find anything to indicate that the DOT does any kind of testing or that third-party testing is required. If I'm wrong on this, please point me to the relevant information.
Look at your head lights, marker and turn.stop lights Richard even your brake system they all have DOT approved so why not trust the DOT label on tires ?
Quote from: luvrbus on January 22, 2020, 04:08:37 PM
Look at your head lights, marker and turn.stop lights Richard even your brake system they all have DOT approved so why not trust the DOT label on tires ?
The problem is that the DOT doesn't do any testing on these products. From what I've read, each manufacturer self-certifies that their products meet or exceed the applicable regulations and standards. The "DOT Approved" marking is only as good as the company that does the testing to ensure standards are met. Some companies likely use a third-party test site. Others do the testing in house.
Having the DOT marking on the tires doesn't mean anything unless the company that self-certified it is reliable and trustworthy.
Here's some interesting reading on the subject:
https://www.sema.org/federal-regulation-aftermarket-parts (https://www.sema.org/federal-regulation-aftermarket-parts)
One interesting section is this one talking specifically about the term "DOT-Approved":
Is "DOT-approved" a legal term? No, NHTSA has no authority to "approve" or "disapprove" vehicle equipment. The equipment is self-certified. Sometimes the term is confused with the DOT symbol, which is required to be placed by the manufacturer on certain items of equipment such as headlamps. This is simply an affirmative statement by the manufacturer that the equipment is compliant with an applicable NHTSA rule.
If you have more specific information on how a tire (or any part) gets the DOT stamp on it, I'd love to know.
Search the mfger. to see if they are ISO 9000,1,2...
certified - if so they would be better from a QAQC standpoint but still not failsafe... I'd rely more on google searches (BBB, etc.) & customer ratings.
Here is what is printed in my DOT manual
Products must meet strict regulations standards,specifactions and testing,I believe you will find the DOT and NHTSA are 2 different federal agencies
Quote from: luvrbus on January 22, 2020, 04:47:41 PM
Here is what is printed in my DOT manual
Products must meet strict regulations standards,specifactions and testing,I believe you will find the DOT and NHTSA are 2 different federal agencies
NHTSA and FMCSA are both sub-sections of The Department of Transportation (DOT).
I agree - the products are supposed to meet strict regulation and standards. Problem is that the companies self-certify compliance.
Reminds me of a trip to Mexico where the tour guide was telling us about the importance of looking for the "925" marking on pieces to let us know that it was real. I asked who does the stamping and who checks to see if the silver meets the standard. The answer was the silversmith. So, the "925" mark was only as reliable as the silversmith doing the marking.
Same for the DOT-approved products like tires. The marking is only as reliable as the company doing the marking.
I'm not saying that any particular tire is not reliable or meeting the standards, just that with newer or less-known manufacturers there is not as long of a track record to check the history.
Found this;
The company designs and produces tires in partnership with manufacturers based in the United States, China, India, Indonesia and Thailand. Omni United owns the Radar, Patriot and Corsa brand names, and markets, sells and distributes several other brand names. The company was founded in 2003 by G.S. (Goldman Sacks)
In fact, there are only two genuine American brands: Goodyear and Cooper. The largest foreign tire companies with plants in the US include Michelin, Pirelli, Continental, Bridgestone, and Yokohama.