I'm starting the search for new tires, hoping to get them installed in early spring. Right now we're running Firestone FS 400 in 315/80R22.5 size. We've been happy with them, and other than the tires being seven years old there is absolutely nothing wrong with them.
My initial thought was to replace them with a new set of the same. The tire dealer I'm hoping to work with is recommending Michelin, mainly I think because that is their main line and the Firestones will need to be ordered in.
So, I looked at the Michelin tires available, and with the FMCA discount they would end up costing about the same as the Firestones. Not sure if they are better, about the same, or a step down.
One tire I'm looking at is the Michelin X Line Energy Z. https://www.michelinrvtires.com/tires/selector/#!/info/x-line-energy-z-coach
Anyone have any experience with this tire?
The Firestone FS 400 spin at 491 rpm. These Michelin also have 491 rpm. Pretty close to the OEM specs of 495.
The other tire I'm considering is a Conti Coach HA3, but it spins at only 488 rpm. Not sure how that will affect performance, and since I'm already feeling that the bus is short on low-end power I don't want to do anything to make it worse.
I run Michelin XZA 11R22.5 on the front wheels. It is because of the soft ride. 7 years old isn't old for a bus tire. (I will duck from the flames) I talked to Michelin about my tires and they said that inspect them regularly and watch for cracks on the side wall and between the tread. No cracks or irregular wear keep going. They said 10 years is okay but because I store mine inside in a heated shop and take the weight off the axles for the winter they said just watch for abnormalities. I decided after 18 years it was time to get new ones. The original looked like new inside and out when I replaced them. I know the shop resold them to a gravel hauler. I am very careful with safety items even though because of the tires some may think otherwise.
They run Michelin on the first line coach company I moonlight at.
Parent company is foreign owned, dividend demanding shareholders.
If running something else saved money, you can be sure they would run 'em...
In RV use, all tires need to be protected from the sun for long life.
Why do we keep repeating these "origin unknown" tire life time limits from decades ago, when tire rubber technology has changed so much since "then"?
488 revolutions per mile, vs 491 vs 495, pace those few feet out, you wouldn't feel the difference in the seat of your pants in a blind test.
If you had transit gearing, then every tire revolution counts in RV use, but that's not you.
happy coaching!
buswarrior
315's are a overkill on a 35ft 4108 is there a reason you want 315's the bus was equipped with 12rx22.5 new,Me I would be looking at a Toyo they ride smooth ,a good tire,cheaper in price and not as prone to UVL checking as the Michelin X Energy.I have the Michelin 315 's but I am at 46,000 lbs,you can save money just on the FET (tax) on the 12R's vs the 315"s .One thing now days the 315's tire manufactures want the 315's on 9 inch wide wheels to reduce sidewall damage so check and see if you have 9 or 8.25 wheels
Richard -
We lost a tire on our "new to us" Prevost about three weeks ago, inside dual. No damage, fortunately.
Turned out the front two and the four drive tires were all 12 years old, and the tags (Firestones, very, very badly cracked) were 16 years old! Scary.
Anyway, after much research, discovered several things:
The Tire and Rim Association does not recommend installing 315/80R22.5s on rims that are less than 9" wide. All eight of the Alcoas on the Prevost were 8.25", so the 315s were out.
The stock OEM tire on your 4108, as with our XL, is a 12R22.5, Load Range H. This tire will fit on an 8.25" rim, per the T&RA specs.
I looked into the FMCA's Michelin program, looking at both the Michelins and the Continentals. Another busnut suggested I consider Sailun tires (which I'd never heard of, found out they're a Chinese product), but they don't have a dealer w/in 250 miles of me, so they were out. Continental also didn't have a dealer nearby, so they were scratched.
Thus, after three days of pouring over website after website and review after review, I ended up with eight 12R22.5 LR H Toyo (Japanese) M170s from our local Les Schwab store (a company that has over 400 stores on the West Coast.) Mounted, balanced, new stems, taxes, etc. was $5300 out the door, which was $940 less than Michelins on the FMCA program. This would work out to about $3975 for your 4108, if you went for the same tire.
I've only got about 100 miles on the Toyos at this point, but I'm very happy with the ride, plus they're very quiet on the different freeway surfaces in my area. Oh, and they turn 490 revs/mile, which is pretty darned close to the GM spec'd 495 on your coach.
FWIW & HTH. . .
;)
Running stock steel wheels? Are they 8.25" or 9" wide?
Bus came to me with the 315s. I assume that they are there because the previous owner ran a fleet of commercial buses and probably had these on hand.
The Michelin 12R22.5 spins at 486 rpm. Starting to get further from the 495 factory mark.
Following some of the suggestions, I've been looking to see what tires are available in the 12R22.5 size. There are not nearly as many options, which is maybe why people are running the 315s instead.
In looking at the bus more closely, I do see that at some time the edge of the tires have touched the air bags in the front. Obviously on full turn the wider 315s are causing a problem. At this time I only see that they've touched the dirt layer, as there is no visible damage to the rubber. But, I suppose that this is reason enough to go back to the 12R22.5 tires. UPDATE: Looks like the turning stops are adjustable, and it should be possible to adjust to prevent this from happening in the future, removing it as a problem. That would make the 315s a viable option moving forward.
One thing I notice is that almost all the 12R22.5 tires I see are spinning at a lower rpm than 495, some as low as 482. Our current tires spin at 495. Speedo is off, and I do notice a lack of low-end power from a dead stop. If I go with a tire with only a 482 rpm am I going to notice any difference? How much more is the speedo going to be off?
RJ - The M170 look interesting. Were you able to find any long-term reviews of the tires? I'm wondering how they'll hold up with regard to weathering and the sun. Any comments on ride quality with them?
https://www.michelintruck.com/tires-and-retreads/selector/#!/
click on bus/RV only and click search.
13 tires to choose from, on each tire, click on "view details"
Click on "tire specifications"
275R are similar to the old 11R
12R are similar to 295/305
the 65 mph/75 mph rating is irrelevant to most busnuts, unless you are running a borderline/overweight front axle thru the desert in the summer time, at 80 mph... but if a busnut wants to obsess, go ahead, its your money to spend.
315 on a coach that wasn't intended to wear them, will allow the front of the coach to wander around, following oh so many more cracks and ruts, and have less bite in the wet and snow. Too much tire contact for the weight in a 40 or 35 footer.
Once you have a coach with too much tire under it for the weight and slide it trying to turn... you won't want it like that anymore... Go try an empty 45'r in a parking lot with snow on it for an immediate and dramatic experience.
The 45 footers in busnut hands will be another big variable, depending on your build decisions. It is much easier for a busnut to design a bigger variation in front axle loading in a 45 than in a 40, too heavy, or too light, depending on where one puts the heavy conversion bits. The big engines also allow for ideas to be acted upon that we'd have called foolish in the 2-stroke days, water and fuel weighs ~8lbs a US gallon... 150 gallons of liquid adds 1200 lbs... which bay shall we put that in? Bigger diesel generator outweighs the old small Onan gas job, big battery banks, solar panels, etc etc...
Many busnut 45's are light in the front end and would drive a lot better with a narrower steer tire than that 315.
Buses were/are notoriously overloaded in passenger service, a busnut has to work hard to replicate those conditions, and usually doesn't need as heavy a tire underneath.
Weigh the coach in fighting trim, opens up a world of possibilities.
happy coaching!
buswarrior
On the topic of tires sitting weathering and basking in the UV sunshine...
You won't get anything of substance.
These tires are supposed to go DRIVE, not sit.
The RV/busnut market is too small, and frankly, we're a pain in the a$$ to the tire manufacturers and sellers.
The rest of the market wants the most miles per tire cost, get 'em installed, there's money being lost sitting here jawing about tire subtleties... busnuts buy tires to let them dry rot.
Where do these BS tire reviews come from? The same guy who has to pay a tech to reset the breaker on his generator is writing about his tire experience???
Commonly on these bus boards over the last 20 years, one may fairly safely consider that tires that get driven don't show weather cracking as soon as tires that sit.
A busnut's best defense is covering/shading the tires when the coach is not in use, drive the coach regularly, and hope for the best.
happy coaching!
buswarrior
I never could wrap my head around the BS with tires on any of these boards.people seldom change tire sizes on their private vehicle but on a bus that is a different story
After reading all the comments, talking to Luke, and spending time online researching, here's what I've come up with:
- The tires on the bus now (Firestone FS400 315s) are in great condition. No sign of weathering or cracking, and lots of tread life left. Other than having a production date code of 4711 they are doing well.
- The problem with the tires being able to contact the air bags is easily remedied by adjusting the stop nut.
- There is no imminent need to replace the tires right now.
- While 12R22.5 might be a better option moving forward, the 315s are bought and paid for.
- I've got an unused FS400 mounted spare.
So, my decision right now is to do the following:
- When the bus is pulled out in the spring, I'll adjust the stop nuts to prevent any future air bag contact.
- I'll get the front wheels balanced.
- I'll keep a close eye on the tires and do frequent inspections.
- At the first sign of cracking or other problems I'll replace all 6 tires with new, probably going with the OEM 12R22.5 size. Right now the Toyo M170 is in the running as a viable option. It's priced right, has relatively good reviews, and spins at 490 rpm.
Sound like a reasonable plan?
Yes, adjust the stop nuts, and lose some turning radius.
Run tires until you can find cracking, sidewall, bead, or in the tread, all need to be watched.
Buy young tires.
Gary can finance a new tire of his own with the Google ad revenue from this thread.
You're welcome.
happy coaching!
buswarrior
I wouldn't fool with the stop adjustment that is a vital adjustment needed on some power steering units maybe not on your GM
I put the Michelin XZA energy tires, and I swear I get better fuel mileage like they advertise.
I run 11 x 22.5 Toyo's ( Made in China)and have for 6 years and they are nice riding tires and have no wear at all. When parked they are on top of thick rubber mud flaps over gravel outside. I take the bus out to stretch her legs each month. I wash them with dish soap and water and a black scrub pad every three months to keep the outer oils agitated and check the pressures monthly if sitting and daily if on the road. :) Cover them when in the yard with vinyl tire covers but not always on those.
Respectfully ...
Another point of view. Do you have any heavy duty truck wrecking or recycling yards nearby you? Places where they would have used "take offs" sets of tires and wheels from heavy trucks that do not need them any more. Wrecks or burn outs.
Sometimes you can find complete sets of 10 or perhaps 8 tires and wheels. Sometimes aluminum wheels with mounted near new tires. One would have to be careful looking for various types of damage. Age. Dents, flat spots, out of round.
Also consider that your used tires and perhaps wheels could find use off road for the independent frugal operator. Quarry or mining use. Anyhow ... just another way of having fun and saving money with your Bus Conversion. Just me here.
As I've said many times, weigh your bus by axle. Most of us will not have enough weight on board to justify the expense of 315's, or for that matter even 12's. 11R-22.5's are much more readily available on the road. Both sets of recent tires, I went 12 years with no problems. I now have Hankook tires-mainly because Freightliner uses Hankook's as their standard tire, and they were $1,500 less than Michelin. Hankooks ride a bit rougher, but not by much over the Michelins. Look into 11R-22.5 16ply for your bus. I had 12R-22.5 on my bus, and switched to 11R-24.5's for highest available street tire. Good Luck, TomC
Quote from: TomC on November 16, 2018, 01:39:47 PM
As I've said many times, weigh your bus by axle. Most of us will not have enough weight on board to justify the expense of 315's, or for that matter even 12's. 11R-22.5's are much more readily available on the road.
The weight limits on the 11R22.5 tires would probably work for us, but the front would not give us much head room without running 110-115 psi. We're at about 11,500 lbs on the front. We did that on the 4106 and found the ride was much harder than with our current tires running at 95 psi.
The bigger problem with the 11R22.5 tires is ground clearance though. Our black tank valve is routed straight out the bottom. There is a fitting just above the floor aiming straight down. To dump, I screw a 45-degree adapter to the bottom and then attach our dump hose. There have been a few times when it was nearly impossible to get the thing connected as with the 315s mounted on the bus, especially if the ground around the dump site isn't flat. Going to 11R22.5 would lower the bus about an inch, and that would make it really difficult to dump the tank.
The 12R22.5 tires have about the same diameter as the 315s, so there should be no issue there. What I've seen in the Toyo specs for the M170 tires in 12R22.5 size is that they have two widths available. One has a loaded width of 13.0" and another has a loaded width of 13.4".
The 13.0" wide tires would be the ones I'd go with, as the 13.4" variant is really no different than the 315/80R22.5 at all. The only difference between the wider of the 12R22.5 tires and the 315s is the load rating. The 315s are 20-ply with an L rating, and the 12R22.5 are 16-ply with an L rating.
As Tomc mentions "have your bus weighed by wheel location" That is the only way to know for sure the weight on the individual tire. I changed to 11R22.5 years ago and while travelling in North Carolina I had a blow out. It was called a zipper tear due to overloading. Goodyear explained to me that a vehicle with air suspension can overload one side by 50% as the vehicle sways side to side. Since than I switched to 12R22.5 and never had anymore issues.
Quote from: Bill Gerrie on November 16, 2018, 04:13:42 PM
As Tomc mentions "have your bus weighed by wheel location" That is the only way to know for sure the weight on the individual tire. I changed to 11R22.5 years ago and while travelling in North Carolina I had a blow out. It was called a zipper tear due to overloading. Goodyear explained to me that a vehicle with air suspension can overload one side by 50% as the vehicle sways side to side. Since than I switched to 12R22.5 and never had anymore issues.
If the weight on a side of the bus can increase by as much as 50% when the bus sways, then weighing the bus when stationary would have only limited value. Or, was the tech at Goodyear expecting us to get tires with 50% extra capacity?
Either way, right now I'm leaning (no pun intended, but it works) towards the 12R22.5 tires, and their load rating at only 105 psi would be about 13,200. Since the axle weighs in at approx 11,600 it would seem like adequate head room.
Of course, if I have to provide for 50% head room, then I might as well stick with the 315s, but that really seems like too much tire.
The problem with the tires being able to contact the air bags is easily remedied by adjusting the stop nut.
that stop isn't put there to stop tire rub....
not sure I'd do that.
If the weight on a side of the bus can increase by as much as 50% when the bus sways, then weighing the bus when stationary would have only limited value. Or, was the tech at Goodyear expecting us to get tires with 50% extra capacity?
Pretty sure Goodyear figured that in to their design/engineering.
Imagine what a C5 Galaxy weighs on impact.
i mean landing :)
The C5 doesn't impact. It merely floats down to the runway like a feather. Hard to believe without sitting all day watching them. Like Dumbo.
So anyone know what the empty axle loads are on the DL3?
Jim
Quote from: eagle19952 on November 16, 2018, 09:03:50 PM
The problem with the tires being able to contact the air bags is easily remedied by adjusting the stop nut.
that stop isn't put there to stop tire rub....
not sure I'd do that.
Yeah - after reading through the manual more thoroughly, it's not just as simple as adjusting the stop nut. In addition, the power steering itself must have adjustments made to place the pressure limit in the correct point so that the tire stop moving
prior to touching the stop nuts. Starting to sound more complex to me and perhaps something akin to opening that proverbial bag of worms.
Perhaps I need to add one item to the list until I change to the proper size tire:
-Drive with extreme caution while doing close-quarter maneuvers in parking lots and such.
As far as I know, I've only had the wheels turned to the extreme left or right only a couple of times, and those were when trying to get out of tight parking areas. In normal driving I don't think I've come close. Of course, if I spent more time doing city driving that could change so I'll have to be aware.
Always the possibility that I put the 12R22.5 tires on there and still have the problem, so I'll still have to check and remedy if so.
A friend of mine just sold his 4107 and it came with 12R22.5 tires. He never had any rub issues and I'm sure the 4108 is the identical chassis. 12R22.5 XZA can go to 120 psi and 7390 lbs single and 6780 dual. More then enough. The adjustment for the wheel stops and the pressure release on the Sheppard box is very simple so you don't take a chance on rubbing the air bags..
Quote from: Jim Blackwood on November 16, 2018, 10:02:14 PM
The C5 doesn't impact. It merely floats down to the runway like a feather. Hard to believe without sitting all day watching them. Like Dumbo.
So anyone know what the empty axle loads are on the DL3?
Jim
Curb weight (empty) is 35,100 lbs on a DL3, you want the empty weight for ea axle ?,GVW is 44,000 lbs with 12Rx22.5 and 48,000 lbs with the 315/80x22.5 tires
Here's the actual difference between the 12R and 11R both 16ply rated-based on the Michelin XZE.
12R- loaded radius is 19.8" and 11,600lbs would be 90psi
11R- loaded radius is 19.2" and 11,600lbs would be 100psi.
So running 11R's you'd loose 6/10" in height and have to run 10 more psi-in my book that's well worth the convenience factor of having 11R's instead of 12R's. Good Luck, TomC
A highway coach is going to handle much better with the 12r's than a 11r tire ,most of the people I know that went to the 11R x 22.5 went back to the 12r x 22.5 on the next set of tires
Re: tire rubbing the internals...
Same 12R size tire, one Goodyear, one Michelin,
One of them would rub one of the bars under an MC8, one wouldn't.
Just the nature of the beasts, slightly different bulge, one just touched, the other didn't.
Noticed the dirt missing shortly after tire swap, swap 'em back, dirt began to accumulate again.
MC8 steer like battleships, so the mechanics had it freed up as far out as we dared, when this was discovered.
Interesting the subtle difference between two "same size" tires.
Experiment and adjust.
happy coaching!
buswarrior
Quote from: TomC on November 17, 2018, 07:53:03 AM
Here's the actual difference between the 12R and 11R both 16ply rated-based on the Michelin XZE.
12R- loaded radius is 19.8" and 11,600lbs would be 90psi
11R- loaded radius is 19.2" and 11,600lbs would be 100psi.
So running 11R's you'd loose 6/10" in height and have to run 10 more psi-in my book that's well worth the convenience factor of having 11R's instead of 12R's. Good Luck, TomC
I don't understand the 6/10 of a inch all tires the side walls are 90% of the tread width,the 11R x 24.5 is about the same height as the 12R x 22.5 but with the naked eye you can see the difference in a 11R x 22.5 vs a 12r x 22.5
I can't agree more with luvrbus then that as I know 2 people that did exactly that. The 12 R is a much better handling tire and smoother ride.
Quote from: TomC on November 17, 2018, 07:53:03 AM
Here's the actual difference between the 12R and 11R both 16ply rated-based on the Michelin XZE.
12R- loaded radius is 19.8" and 11,600lbs would be 90psi
11R- loaded radius is 19.2" and 11,600lbs would be 100psi.
So running 11R's you'd loose 6/10" in height and have to run 10 more psi-in my book that's well worth the convenience factor of having 11R's instead of 12R's. Good Luck, TomC
The radius is only half the story. With regard to the ride height, the tire diameter is important. The 11r is almost two inches less than the 12r in diameter, which would drop the ride height 1".
Quote from: buswarrior on November 17, 2018, 08:42:19 AM
Re: tire rubbing the internals...
Same 12R size tire, one Goodyear, one Michelin,
One of them would rub one of the bars under an MC8, one wouldn't.
Just the nature of the beasts, slightly different bulge, one just touched, the other didn't.
Noticed the dirt missing shortly after tire swap, swap 'em back, dirt began to accumulate again.
MC8 steer like battleships, so the mechanics had it freed up as far out as we dared, when this was discovered.
Interesting the subtle difference between two "same size" tires.
Experiment and adjust.
happy coaching!
buswarrior
Even with the same tire manufacturer and same tire. Toyo offers their M170 in two widths - 13.0 and 13.6
Obviously one would be more likely to rub than the other.
To clarify-loaded radius is the distance from the ground to the axle when mounted with rated load and air pressure in the tire. All this talk about over an inch isn't true. 6/10" is all the difference your bus would be between the 12R and the 11R. Good Luck, TomC
Quote from: TomC on November 18, 2018, 11:32:40 AM
To clarify-loaded radius is the distance from the ground to the axle when mounted with rated load and air pressure in the tire. All this talk about over an inch isn't true. 6/10" is all the difference your bus would be between the 12R and the 11R. Good Luck, TomC
Actual drop on a Eagle measuring from the body to the pavement with 11R x22.5 is almost 2 inches, so they go with 11R x 24.5 but I'll take your word on the 6/10 of inch 8) since I don't recall the brand of tire
Something not mentioned here is the mph difference in running shorter tires. I run 315 80r 22.5's for the GVW on my 2 axle RTS @ 36,900 lbs. Tom is good at calculating top speed. I like the taller and wider 315's.
Quote from: TomC on November 18, 2018, 11:32:40 AM
To clarify-loaded radius is the distance from the ground to the axle when mounted with rated load and air pressure in the tire. All this talk about over an inch isn't true. 6/10" is all the difference your bus would be between the 12R and the 11R. Good Luck, TomC
There are two variants of the Toyo M170 in the 12R22.5 size. One is nearly identical is size to the 315 size, with a loaded radius of 19.8"
The M170 in size 12R22.5 in the narrower width is only 19.0" loaded radius. This is the one I'd be installing, because it's the one that would help with the clearance issue. The wider M170 is the same width and same loaded radius as the 315s, and would most likely have the same clearance issue.
315/80R22.5 19.8" loaded radius
12R22.5 19.0" loaded radius
11R22.5 18.6" loaded radius
So, the drop from the current 315 size to the 11R size would be 1.2"
As it is, going from the 315s to the 12R would be dropping the ride height down .8" and make getting the tank hose on more difficult (impossible in some places). Going down another 1/2" would be worrisome if I hope to be able to empty the tank without too much cussing.
Top speed is not a worry right now. With the 315s I can hold a cruising speed over 70 with no problem on flat roads. As it is, the speed can easily creep up over 75 if I'm not watching. I like to keep it to around 65 at the most.
Richard -
My Les Schwab dealer just got back to me today with some "inside" information on the Toyo M170s in the 12R22.5 size that you see on their commercial tire website.
SKU #546090 is the current production tire, and the ones put on my coach a few weeks ago.
SKU #546310 is the new replacement for the 546090 as current stock in the system is depleted. It has a slightly different tread pattern, slightly higher load/speed numbers, has a slightly taller static loaded radius (19.7 vs 19.0), and a slightly wider overall inflated width (12.4 vs 12.0.) This new tire is also smaller than a 315/80R22.5, but not by much. Biggest difference is the 315 has a greater weight capability and, surprisingly, a lower speed rating! (At least in the Toyo line, others may be different.)
Anyway, thought you'd find this info interesting as you ponder new shoes for your coach.
FWIW & HTH. . .
;)
Thanks for the updated information RJ.
That confirms what I've been thinking, but I discovered a part of this that confuses me.
If the tire is contacting the airbag on full turns, it's most likely the corner of the tread that makes contact. I suspect that the width of the actual tread is the same on both of these two model variants, so the only real difference will be the loaded static radius.
The current production tire, the one with the smaller radius, is probably going to be the one with the most clearance between the tire and the air bag. However, it will be the one that gives me 0.7" less clearance under the bus. Maybe not that much, but I worry that it may be enough of a drop to make putting the black tank hose on more difficult or not possible in some locations.
There are so many variable with this that it really gets to be mind boggling after a while.
I had the 12's on the MCI when I first got the bus then went to the 315's but went back to the 12's because it FELT easier to steer
Dave