MCI advertises that a J4500 gets 9.66 MPG at a steady 65 MPH in independent testing. Perfect conditions probably, but it still does it.
See item #3 on page 18 of the attached brochure.
The interesting thing about that claim is that MCI doesn't offer the AS Tronic transmission anymore, only the Allison "Gen V" automatic. So that fuel economy was done with the Allison and the AS 12 is known to get a further 10% better fuel economy than the Allison. A 10 MPG intercity bus ?
The brochure also says "Fuel economy optimized rear axle ratios delivering up to 19% better fuel economy in certain configurations" on page 25.
So how is MCI setting up these buses to get such good fuel economy ? They are using the Cummins ISX12. What RPM is the engine running at 65 MPH ?
Cummins developed the ISX 12 motor coach engine low horse power 385 t0 425 hp with high torque at low rpm's Prevost is playing catch up using their D13 with electric fans and around 450 hp down from over 500 hp and they are a dog
Quote from: luvrbus on August 22, 2020, 09:37:35 AM
Cummins developed the ISX 12 motor coach engine low horse power 385 t0 425 hp with high torque at low rpm's Prevost is playing catch up using their D13 with electric fans and around 450 hp down from over 500 hp and they are a dog
The new J4500 has electric fans too.
This guy is running a 500HP D13 and getting fantastic fuel economy. >9 MPG on a lot of trips. He shows the MPG indicated on the dash. He says 8.5 MPG lifetime MPG running at the speed limit all the time.
https://www.youtube.com/watch?v=8uwc7F3ixpg
It can't be that gutless because he passes other trucks going up passes, while loaded to 72-80,000 pounds. But low lugging engines feel gutless.
His truck has a 12 speed iShift. It has 2 modes, economy and performance. He uses performance when going up a pass.
I'm targeting a coach with the 12 speed AS Tronic and the ISM. 2nd choice is a DD S60. Last choice is the Cat. There were a ton of issue with the C12/13 in these buses.
Give me break I pushing a box down the road@ 48,000 lbs with a ISX 15, 650 hp and with the generator and Aqua.Hot I am at 7.3 mpg and sometimes I run 70 to 75 mph.The Jake brake is a marvel on the ISX 15 .Cummins upgraded me from 600 hp to 650 hp for better fuel mileage believe that or not and it worked
Quote from: luvrbus on August 22, 2020, 10:16:42 AM
Give me break I pushing a box down the road@ 48,000 lbs with a ISX 15, 650 hp and with the generator and Aqua.Hot I am at 7.3 mpg and sometimes I run 70 to 75 mph.The Jake brake is a marvel on the ISX 15 .Cummins upgraded me from 600 hp to 650 hp for better fuel mileage believe that or not and it worked
What kind of bus do you have ?
All you have to do is look at the ECM on those engines. They don't lie. And the VNLs are very aerodynamic.
Modern trucks are running direct drive transmissions so that there are no gears involved when cruising, along with a 2.60:1 axle ratio. Which is like a 3.3:1 with an OD transmission.
I think the fastest axle ratio available for a J is a 3.36:1.
The Silver Leaf reads the ECM direct or like me it will calculate the gals used from the fuel tank when using the Aqua Hot and generator I am around 7.8 using just the ECM.I know a little about Volvo engines a friend in Phoenix owns the largest trucking co in the US and probably owns a thousand or more of Volvo trucks plus other brands,he owns Volvos with ISX 15 Cummins also along with the Internationals,Petes,and KW's in his fleet
There's more to these fuel economy claims than just the choice of hardware.
The acceleration rate is controlled by the computer, not the driver's right foot.
So programmed, the Allison equipped will take just as long to reach highway speed as the AStronic, if not longer.
There's no high powered blast off and 9 mpg grouped together...
But at least it is smoother, no gear shifting pauses to tire out your seniors tour group, heads rocking back and forth constantly...
Read further, the direct drive choice also means heavier driveline parts, so the truck starts getting heavier in the pursuit of fuel economy. No free lunch...
Rpm is way down at 1100 give or take, at highway speed.
Downright spooky...
Happy coaching!
Buswarrior
Would you gear a S60 or ISM to cruise at 1100 RPM at 65 MPH ? Or is that only applicable to the new wonder engines ?
The 12 speed Astronic gear splits are 27-29% versus 34% for a standard 10 speed. So even if top gear is super low RPM, the next gear down is 1400 RPM, which is still a reasonable cruising RPM. The next gear down after that is 1800 RPM. So you really have 3 gears to chose from to cruise at 65 MPH, if you set it up that way.
my sweet spot on the cat 3406e is 1525 rpm and that is about 67 mph but most times I run at 62 mph . at this speed it makes most hills flat so I use cruise control a lot and at that speed my mileage is 7.9 -8.3 mpg . but this is on a pre emission 1875 foot pounds of torque 550 hp engine 8)
dave
Very misunderstood in busnut circles is the progression of the engines through the various emmissions regimes.
Any particular engine, you have to know what it was designed for, and what rpm is intended to deliver the power and fuel economy compromise for the vehicle it is going in.
Truck guys generally don't know about buses either..
Knowing that engine is really important, for instance, some of the last Cat motors, if it was run as little as 100 rpm away from the magic rpm, the fuel consumption curve was "V" shaped, and would bankrupt the fuel budget.
Generally speaking, the older it is, the faster it spins, the newer it is, the slower it may be spun.
Also, the whole Allison transmission thing will bite busnuts hard in the future. Just buying a "B500" or "4060" off someone cheap...They are not all capable of aggressive downspeeding, a whole ton (maybe 2 decades decade's worth?) of them can't spin below 14xx rpm, the lube pump in them was never intended to maintain it at cruise any slower. Lets be fair, cruising at 1500 was quite magical back in the day...
So, you have to have the right Allison to match the right engine.
Lots of research of information not readily avialable anywhere but a grizzled veteran at the manufacturer.
Happy coaching!
Buswarrior
So what would be the most efficient cruise speed for a '96 DL then? (no tachometer)
Jim
Quote from: Jim Blackwood on August 23, 2020, 07:22:09 AM
So what would be the most efficient cruise speed for a '96 DL then? (no tachometer)
Jim
Judging from my own personal experience, most efficient cruising speed depends on the terrain. I generally run at 65 which puts rpm right at 1550 which is just over the optimum rpm for the series 60. The series 60 likes 1200 to 1500 rpm for maximum torque output at best fuel economy. When in Commifornia I am limited to 55 because I tow. When on flatlands I may notice about 1mph better economy, but in the mountains it is worse. If I maintain 60 to 65 mph in the hills I actually see an improvement in economy over doing 55mph. So based on my experience it would seem that when lower power output is necessary to maintain speed, running lower in the torque curve seems to be the ticket. But when requiring maximum power to maintain speed it seems running closer to the top of the torque curve gets the result.
I would assume however that the same engine with different torque/hp setting may not observe the same result. I definately noticed a difference going from 370/1450 to the current 470/1550 setting. Flatland driving didn't change much but I did get a boost in economy in the hills.
Quote from: Jim Blackwood on August 23, 2020, 07:22:09 AM
So what would be the most efficient cruise speed for a '96 DL then? (no tachometer)
Jim
What engine version is in it?
You missed the point, it all depends on the particular engine that is in it. Could be a 95 or a 97 engine in a 96 coach... and as noted, what engine settings?
This is such a particular exercise, the advice for one thing will be completely the wrong advice for another.
The answer must be specific to your exact DNA, or you're wasting yer time.
And it was still popular back then to gear buses with 4.56 differentials for rocket ship top gear performance. The truck guys stare in disbelief, cuz a 4.56 gear at the time went into a tractor expected to gross 135 000 lbs...
A most hazardous area for casual answers, and whoever gives the advice has to know buses and their peculiarities.
And none of us drive far enough for these shades to make a difference. Leave the engine running while you fuel, and the savings from the weekend are gone...
Happy coaching!
Buswarrior
The generation 5 Allison is remarkable the driver or the engine cannot out smart one
That's how they get the reliability out of them now. Also the constant addition of additional speeds helps to use lighter and more compact components. The shock to the trans parts is much less in a 10 speed, compared to say, a 4 speed, since the rpm change difference when shifting is is significantly less. Plus computer controlled clutch and torque converter apply.
Quote from: buswarrior on August 23, 2020, 05:54:30 AM
Very misunderstood in busnut circles is the progression of the engines through the various emmissions regimes.
Any particular engine, you have to know what it was designed for, and what rpm is intended to deliver the power and fuel economy compromise for the vehicle it is going in.
Truck guys generally don't know about buses either..
Knowing that engine is really important, for instance, some of the last Cat motors, if it was run as little as 100 rpm away from the magic rpm, the fuel consumption curve was "V" shaped, and would bankrupt the fuel budget.
Generally speaking, the older it is, the faster it spins, the newer it is, the slower it may be spun.
Also, the whole Allison transmission thing will bite busnuts hard in the future. Just buying a "B500" or "4060" off someone cheap...They are not all capable of aggressive downspeeding, a whole ton (maybe 2 decades decade's worth?) of them can't spin below 14xx rpm, the lube pump in them was never intended to maintain it at cruise any slower. Lets be fair, cruising at 1500 was quite magical back in the day...
So, you have to have the right Allison to match the right engine.
Lots of research of information not readily avialable anywhere but a grizzled veteran at the manufacturer.
Happy coaching!
Buswarrior
Well said. I especially agree with the B500 stuff.
I found the Cummins spec sheet for the ISM410 EPA2007 engine.
It says:
"For maximum fuel economy or for vehicles intending to
cruise greater than 65 mph, gear for an engine speed of
1500 rpm at the 65-mph checkpoint (1600 rpm for the
ISM 410)."
I am @ 1250 rpm @ 65 mph I drove a friends new J with ISX 12 it was 1100 rpms @ 65 mph,ISM Cummins are popular in RV's set @ 500 hp
So then just drive it at 65 or 70 and don't worry about it huh?
Jim
Cat's take on RV fuel economy.
Quote from: someguy on August 23, 2020, 02:02:12 PM
Cat's take on RV fuel economy.
[/quote
Cat used to be at all FMCA conventions for RV's all 3 were CAT,Cummins and Detroit with their sales pitches with movies lol even pop corn,the problem CAT had was all their engines were developed for equipment and they adapted those engine for highway use some times it worked great other times it didn't
Quote from: someguy on August 23, 2020, 02:02:12 PM
Cat's take on RV fuel economy.
Cat's 2005 printed materials...
You can't talk engines without the qualifier.
Happy coaching!
Buswarrior
FYI, a 2006 E4500 with the ZF AS Tronic 12 speed transmission cruises at 1330 RPM at 65 MPH, based on tires with 490 revs/mile, 0.78 OD ratio and 3.21 axle ratio.
In 11th gear (1.0 ratio), the engine runs at 1700 RPM at 65 MPH.
In 10th gear (1.27 ratio), the engine runs at 2100 RPM at 62 MPH.
10th gear at 55 MPH is 1831 RPM, which is full power for most engines. A 40,000 pound coach takes 475 wheel HP to climb a 6% grade at 55 MPH.
FYI, the only difference between the 10 and 12 speed ZF AS Tronics is that the 12 speed has 2 extra creeper gears and 2 reverse gears instead of 1. The gear ratios of the upper 10 gears are the same in both.
The ZF AS Tronic 12 speed has nearly identical spread as the standard Eaton 10 speed, except the 12 speed splits are 25-32% whereas the 10 speed splits are 35-40%. On average the ZF splits are 8% tighter.
At 1500 RPM, 8% is 120 RPM tighter. With a standard 10 speed the 40% splits are 900/2100 RPM. With the ZF the splits would be 32%, which is 1020/1980 RPM. Nobody shifts at 1500RPM, I'm using that to show the ZF can stay in the rev range whereas the 10 speed can't.
If the transmission shifts at 1800 RPM, the ZF picks up at 1224 RPM, whereas the 10 speed picks up at 1080 RPM. The C13 makes constant torque from 1200 to 1500 RPM and peak HP at 1800 RPM. So the ZF shifts fit within that peak torque to peak HP band whereas the 10 speed makes the engine go beyond peak HP (to 2000 RPM) in order to pick up the next gear at peak torque.
I cannot wait to haul @$# up hills with a decent transmission for once. Not that I want to race up hills fast. I just want some gear ratios to let the engine do its job without revving its brains out.
Did you do the math percentages in the correct direction? Your rpm drop calculations are WAY too big.
The paper can say what it wants, none of these engines will "make power" up near the top of the rpm range. Spinning them up there doesn't make much push... but it sure will consume fuel.
You do kniow that HP is a marketing number, always has been. Where's your torque... stay there.
As for the ZF 10/12... what differentials were being put behind/infront of each, i ask rhetorically...? You don't suppose the lower gears were to allow a taller diff to get cruise speed down, without losing startability...?
The 12 speed will start off in 3 and even 4 from a stop, and skips gears all the time, it doesn't touch each one .
Keep going, you have a ways to go yet...
Happy coaching!
Buswarrior
In practical every day terms, the ZF A S Tronic transmission was not a nice transmission. Most driver's hate it. It shifts quite roughly in stop and go traffic in town. It will rattle the dishes in your cupboards. Like BW says, it rarely starts in 1st or 2nd, and skips gears according to conditions. It doesn't always know what gear to be in. You have to baby it with manual shifts. I would just look for an Allison B500. Smooth, always in the right gear up or down.
If I wanted a 10 speed auto shift I would skip the ZF and buy the 10 speed Allison,I haven't figured out why Allison is not letting bus manufactures have the 10 speed yet ,I know they were testing those in buses
Quote from: lostagain on August 25, 2020, 06:15:42 AM
In practical every day terms, the ZF A S Tronic transmission was not a nice transmission. Most driver's hate it. It shifts quite roughly in stop and go traffic in town. It will rattle the dishes in your cupboards. Like BW says, it rarely starts in 1st or 2nd, and skips gears according to conditions. It doesn't always know what gear to be in. You have to baby it with manual shifts. I would just look for an Allison B500. Smooth, always in the right gear up or down.
Meritor rebranded the ZF AS Tronic as the Meritor Freedomline transmission. It is a really good transmission, almost as good as the Volvo iShift. In fact, Volvo used it behind the D13 for a while.
Meritor had to cease selling it because some of the technology infringed on US patents held by Eaton. Meritor ended up paying Eaton $500M to settle.
There is no reason for a PROPERLY working AS Tronic transmission to shift roughly. The AS is a manual transmission with shift rod actuators on top of it. Not an XY box like the Ultrashift. It does not shift under power. Any jerkiness you felt was from the clutch releasing awkwardly.
Generally if the AS is shifting poorly it is because the clutch isn't set up properly or has been abused. That happens if drivers use the throttle pedal to hold the vehicle like they would the torque convertor. In a vehicle with a properly working clutch, they shift super smooth, up and down.
Why use an AS over a B500 ?
- more gears / better gear spacing
- less heat. The AS doesn't even need a cooler
- about 400 pounds lighter
- more efficient
- lets the engine lug and use its torque
- less expensive to replace
- I could rebuild one if I had to
- works better with the exhaust brake
I hate automatic transmissions. Especially Allisons.
BTW, you can't even get a manual transmission in a new Volvo VNL. They are all iShift.
Quote from: lostagain on August 25, 2020, 06:15:42 AM
Like BW says, it rarely starts in 1st or 2nd, and skips gears according to conditions. It doesn't always know what gear to be in.
The 12 speed starts out in 3rd, where it should. 1st and 2nd are creeper gears. The operator can manually jog to whatever start gear he wants, up to 4th, I think. They skip shift quite well. Sounds like the transmission you were running wasn't set up properly. 3rd in the 12 speed = 1st in the 10 speed.
There is a setup file for both the engine and the transmission controllers. Everything is tunable, but the off the shelf settings should work fine. Not sure what was wrong with the transmission you drove. One of the parameters in the transmission setup file is the default start gear.
Most drivers are wrong apparently. Aren't y'all glad there is someone around to point that out?
Jim
See Section 3 Maintenance. Page 53. Release Fork Greasing Procedure.
Section 5 has calibration procedures if the shift solenoids are ever opened up. But unless the transmission is jerking because it is being shifted under power, that isn't the problem you are describing. What you are describing is a clutch issue.
All the actuators in the AS are pneumatic. The flow to them is controlled by solenoids. If the solenoids are dirty they might respond in a jerky manner.
FYI, both the Ultrashift and the Ishift use electronic clutch actuators and they fail periodically and are expensive. I think it is good that the AS uses a pneumatic clutch actuator.
Another advantage with the b500 is full boost throughout shifts,
I'm running 1450 rpm at 68mph with 3.73 rearend in 5th gear
Trying to keep up with sonnie greys bus lol
Look what I stumbled across, a video of a C13/ZF in a J4500.
https://www.youtube.com/watch?v=uR8FpJ2zI-o
Doesn't seem jerky to me.
Bonus pack, there is a second one. https://www.youtube.com/watch?v=Arywpn6IsPc
"I remember falling asleep to that sweet Detroit turbo in a comfortable seat while cruising on the freeway on a field trip to DC In the morning I just had to ask the driver what the bus%u2019 model was and what engine it was equipped with" Sounds like a happy passenger.
I wish he had it out on a mountain pass.
And another one.
https://www.youtube.com/watch?v=eV3gL3z2fH0
Someguy, I have driven more than one ZF, and more than one Allison, and many other engine/transmission combinations in buses and trucks.
I am trying to help you with real life driving experience, but you seem to know it all... But you don't listen very well...
This isn't my first rodeo with truck stuff. If it doesn't shift well, I'll fix it. It's a pretty simple concept. It shifts exactly how one would double clutch a 10 speed. The only thing that will cause jerkiness is if the clutch is engaging wrong. And I actually rode in a Volvo that I thought had an iShift but I've come to find out had a Meritor Freedomline in it. Very smooth.
I have no idea what was wrong with your unit, but there are lots out there that shifted well. Volvo sold a lot of trucks with the Meritor Freedomline in it before the iShift came out.
Here is a VNL with the AS Tronic in it. The driving starts at 4:20
https://www.youtube.com/watch?v=66n6DDjIiZA
And yes at 5:42 it starts out in 3rd gear. As it should with no trailer.
Good luck!
Quote from: lostagain on August 26, 2020, 06:55:13 AM
I am trying to help you with real life driving experience, but you seem to know it all... But you don't listen very well...
No worries JC. You can lead a horse to water... Only disappointment after all the advice he has received is that he ends up being another ASK0HOLIC which we have seen all to often in the past. Good luck!
You guys got a problem with newbies asking a bunch of questions ?
Quote from: lostagain on August 26, 2020, 06:55:13 AM
I am trying to help you with real life driving experience, but you seem to know it all... But you don't listen very well...
Pretty sure he's never replied to me... ???
Quote from: someguy on August 26, 2020, 02:40:06 PM
You guys got a problem with newbies asking a bunch of questions ?
Nope, just one anonymous newbie who does not have a bus or indicate where he is located. Say, you're not some Russian spy sent in to disrupt busnuts by machine-gunning in questions, are you? Or are you working for Facebook and you want to do Bulletin Boards in? You need to have a better regard for the wisdom of others that have more miles on the road than you.
If "someguy" isn't a confederate of Gary's, driving up the google ads click statistics, then "someguy" better negotiate a cut of Gary's google cheque for driving the Board activity way up... !!!!
Taking the time to share quality information with someone who it turns out already has answers, and openly shrugs off experienced warnings... it is a bit rude.
How about some contributions of IDEAS, which contribute to the collective creativity? Asking us for ours and then being dismissive doesn't help anyone.
Copying all of us, doesn't advance the hobby?
Happy coaching!
Buswarrior
Quote from: lostagain on August 26, 2020, 06:52:53 AM
Someguy, I have driven more than one ZF, and more than one Allison, and many other engine/transmission combinations in buses and trucks.
Lostagain, I sent you a PM.
I'm a relative newbie here too but an old hand on other forums and I understand a bit of the etiquette. We've got a guy on one forum named Barrie. When Barrie has to loosen a bolt he asks how it's done and where to buy the best wrench for the job. When Barrie adds gas he wants to know if he should buy his paper towels at WalMart. We've gotten used to Barrie but it took some doing. OK that's all an exaggeration but I think it helps demonstrate the point. Forums are a social society with developed ways of conduct. If you don't bother to learn those ways it causes friction.
So, as mentioned, here's a guy (someguy) who is completely unknown even though he's been here since '06 maybe lurking. At least he registered that long ago. Is he a real person? We don't know. He could be an established member playing troll. It does happen. No name, no age, no location, no bus. Sounds like about 50, reveals specialized knowledge, acts like a know-it all. Not a great way to start out, but just about what you would get from a troll. Why? Well it sure drives the numbers up. So until I see some personal info provided that's going to be my opinion. Not that I mind particularly, I'm inclined to bait trolls just as a pastime. And overall running the numbers up is a good thing. Besides, this guy is raising issues that should concern us. It'd be good if he could do it in a less offensive manner, but hey, some people are just naturally offensive and can't help it. Doesn't necessarily make 'em bad people.
Jim
I was just on the Allison Transmission web site. And I see no mention anymore of the TC10. I don't believe it is being offered anymore. Good Luck, TomC
Quote from: TomC on August 28, 2020, 10:39:57 PM
I was just on the Allison Transmission web site. And I see no mention anymore of the TC10. I don't believe it is being offered anymore. Good Luck, TomC
I saw a Waste Management 2020 Pete with one ,talking to a friend at Williams a new Allison 10 speed is in testing a fully automatic like the newer passenger cars and pickup's have
Maybe he is an RV saleman or works selling ZF tranny's for commission. ;)
Quote from: Dave5Cs on August 31, 2020, 04:15:52 PM
Maybe he is an RV saleman or works selling ZF tranny's for commission. ;)
How dare you! :o :o :o :o :o :o ;D
If the passengers could choose... espeically the typical seniors group...
They would pick an automatic Allison every time.
Automated manual transmissions do NOT deliver a smooth ride in so many real world situations.
But i'm just another person typing words onto the internet, hiding behind a pseudenom...
Happy coaching!
Buswarrior