Reply
 
Thread Tools Display Modes
 
Old 11-04-2019, 07:43 PM   #1
Mini-Skoolie
 
Join Date: Oct 2019
Posts: 13
Gear Ratio - Speed & Mileage Sweet Spot? - And other Stuff

I am a skoolie wannabe / newbie who's getting fairly set now, on what I THINK might be my ideal bus, in terms of coach-type-size at least. I'm headed toward a kind of grand-scale, bucket-list tour of North American with my lady, visiting old friends all over the country, chasing good weather, with lots of national parks and natural wonders along the way, hoping to overstay our welcome everywhere we go.

Our land yacht's gotta be big enough to live aboard for months at a time, but small enough to be admissible to camping places where 35 feet is the limit, and maybe even the occasional parking lot that might let me hog two spaces (for the price of three)? Overall length of 31 to 33 feet would be my ideal. I want about 24 - 25 ft. of linear living space, aft of the driver's seat, with headroom a little over 6 feet (I'm only 5'10").

I presently see a lot of these 10-window Internationals (pictured) at auction, selling for $2,500 to $4,000, depending on age and condition. This one's a 2004 from e-Bay where it just sold for $2,700. There's a few for sale now--some with the handicap back, which seems like a plus(?).

Now to the drive train thing: In general, it seems like International's diesels lead the hit parade. Is that right? I detect special reverence for the DT 466E and the DT 360, but less enthusiasm for the 444, which is what seems most often to power the buses for which I lust. So what's your vote for best power plant? Secondly, I almost always hear the Allison name for transmissions, and I frankly don't know squat about the options for rear differentials. But I DO know that when I'm changing locations, I want to keep up with at least near-freeway speeds (60 - 65?) without winding out the RPMs and wasting a ton of fuel.

And so, ye most sage of skoolie pundits, I besiege thee: In 10-window skoolie heaven: What is the dream engine? What is the magic gear ratio for a "highway" bus? And what mileage is realistic with that combination?

Humbly,

- Jim

My Great Escape is offline   Reply With Quote
Old 11-04-2019, 08:14 PM   #2
Bus Geek
 
EastCoastCB's Avatar
 
Join Date: Sep 2014
Location: Eustis FLORIDA
Posts: 19,293
Year: 1999
Coachwork: Thomas
Chassis: Freighliner FS65
Engine: Cat 3126
Rated Cap: 15
In a bus that size you want any pre-2004 Cummins, Cat, or International-pick your flavor they're all pretty good as long as they're not ancient and not EPA. With any non-545 transmission. For rear gearing you want 4.44 or numerically lower. Oh- on full size tires- 10R or 11R. Avoid lowrider buses. High headroom and air ride and two things I look for.
Happy hunting.
__________________
.
Roll Your Own Build Thread
EastCoastCB is offline   Reply With Quote
Old 11-05-2019, 07:22 PM   #3
Mini-Skoolie
 
Join Date: Oct 2019
Posts: 13
Transmissions

Thanks so much for the clarity, but please forgive my ignorance--when I see
"Allison 545" does that translate to a 5.45 gear ratio, or is it a more general designation of a transmission type that could include some different gear ratios? If I follow, you're saying the lower the gear ratio number, the more forward speed you would get at a given engine RPM, right? I understand you to mean a 4.44 ratio would characterize a bus that is suited for highway speeds without having to over-rev the engine, and if the ratio was lower, all the higher expected speed per RPM.

Thanks again!
My Great Escape is offline   Reply With Quote
Old 11-05-2019, 07:26 PM   #4
Bus Geek
 
EastCoastCB's Avatar
 
Join Date: Sep 2014
Location: Eustis FLORIDA
Posts: 19,293
Year: 1999
Coachwork: Thomas
Chassis: Freighliner FS65
Engine: Cat 3126
Rated Cap: 15
Quote:
Originally Posted by My Great Escape View Post
Thanks so much for the clarity, but please forgive my ignorance--when I see
"Allison 545" does that translate to a 5.45 gear ratio, or is it a more general designation of a transmission type that could include some different gear ratios? If I follow, you're saying the lower the gear ratio number, the more forward speed you would get at a given engine RPM, right? I understand you to mean a 4.44 ratio would mean the bus is suited for highway speeds without having to over-rev the engine, and if the ratio lower, all the higher expected speed per RPM.

Thanks again!
545 is the model of Allison auto transmission. Its got no lockup torque converter and a 1:1 fourth gear.
The lower the number numerically the more highway friendly. The lower the number the "higher" the gearing.
__________________
.
Roll Your Own Build Thread
EastCoastCB is offline   Reply With Quote
Old 11-05-2019, 07:48 PM   #5
Bus Crazy
 
Join Date: May 2016
Location: Georgia
Posts: 1,697
Year: 2001
Coachwork: Blue Bird
Chassis: IH
Engine: T444E
Rated Cap: 14
An AT545, as noted, has a 1:1 top gear and no lock-up torque converter. Here's some examples:


My bus has a 5-speed manual and a 1:1 top gear. I have 5.38 rear-gears and 10R22.5 tires, which have a diameter of ~40". I have a top speed of 55 at ~2600 RPM (which is close to max RPM for my T444E) If I swap to 4.44 gears and recalibrate the speedometer (electronically, I'm told) I calculate a top speed around 65. 4.10 gears will get me close to 70, and 3.91 gears will bring my top end to 74-ish. Of course, at lower speeds it'll drop my RPM's and the engine seems content to cruise at 1800-2000, and it gives me some top end if I feel the need to pass someone. If I find some gears between 3.50-ish and 4.10, like maybe 3.78 or 3.54, I feel like I'll get a good cruising RPM.


Be fair warned that on an AT545, the torque converter doesn't lock up - it's always "slipping". If you switch to really high (lower numerically) gears, it will take more torque through the transmission to maintain a speed and climb hills, generating more heat. You will want to monitor transmission temps, excessive heat will kill one quickly.
Brad_SwiftFur is offline   Reply With Quote
Old 11-05-2019, 07:49 PM   #6
Bus Geek
 
Join Date: May 2016
Location: Eastern WA
Posts: 5,727
Year: 2002
Coachwork: Bluebird
Chassis: All American RE (A3RE)
Engine: Cummins ISC (8.3)
Rated Cap: 72
You may want to consider transit style buses. They will yield more living space per foot of length.

Regarding engines, I strongly prefer inline six's over V8's. The International DT's have a great reputation but everyone knows that the Cummins 8.3 is the best OK... Maybe I could a little biased
PNW_Steve is offline   Reply With Quote
Old 11-05-2019, 09:09 PM   #7
Mini-Skoolie
 
Join Date: Oct 2019
Posts: 13
Thanks for the wealth of info! Brad and Steve (or anyone), could you venture any mileage figures to go with those gearing and engine specs? Given I'm not running an express service, I'm happy to just be able to cruise at moderate revs, and hopefully somewhat economically, anywhere meaningfully above 60 MPH. (I hate the idea of being too much of a roadway pariah!)

The transit bus is something I hadn't considered, mostly because I'd like to keep the overall footprint down. I have room on my property to park a bus, given it's not over about 30 - 33 ft. long--though I guess there's short transit buses? I also didn't know if they'd be much for fuel economy. I'm plenty used to being comfortable in small living spaces, having owned--and lived aboard--a couple of sailboats in years past. Compared to those boats, a 30 - 35 ft. skoolie would be like the Titanic. (Well, just where living space is concerned, I hope!)
My Great Escape is offline   Reply With Quote
Old 11-05-2019, 11:35 PM   #8
Bus Crazy
 
Join Date: May 2016
Location: Georgia
Posts: 1,697
Year: 2001
Coachwork: Blue Bird
Chassis: IH
Engine: T444E
Rated Cap: 14
I'd estimate fuel economy somewhere between 8-10 MPG for a diesel powered bus full sized, even a shorty, some of us get a little better, others not so much, dependent partly on how fast you drive it.
Brad_SwiftFur is offline   Reply With Quote
Old 11-06-2019, 12:44 AM   #9
Mini-Skoolie
 
Join Date: Oct 2019
Posts: 13
Allison 1000 - 2000 ?

Having taken the wisdom on the AT 545, especially for long-distance highway travel, it appears from other posts here on s.net that the Allison 1000 to 2000 series gearboxes are about as beloved as the 545's appear maybe not to be?

I just saw this bus sell on eBay, perfect size for me, and with an AT2000. Should I feel like I just saw my ideal bus, to be sought the NEXT time one comes up?

But now, it's a pusher with a CAT 7. Is that all the more reason to believe "that was my bus" or...not? I've noticed some negative comments around here on CATs in general. Is that the wrong impression?

Here's the auction, just ended:

https://www.ebay.com/itm/Thomas-/113...p2047675.l2557

My Great Escape is offline   Reply With Quote
Old 11-06-2019, 12:25 PM   #10
Bus Geek
 
Join Date: May 2016
Location: Eastern WA
Posts: 5,727
Year: 2002
Coachwork: Bluebird
Chassis: All American RE (A3RE)
Engine: Cummins ISC (8.3)
Rated Cap: 72
Quote:
Originally Posted by My Great Escape View Post
Having taken the wisdom on the AT 545, especially for long-distance highway travel, it appears from other posts here on s.net that the Allison 1000 to 2000 series gearboxes are about as beloved as the 545's appear maybe not to be?

I just saw this bus sell on eBay, perfect size for me, and with an AT2000. Should I feel like I just saw my ideal bus, to be sought the NEXT time one comes up?

But now, it's a pusher with a CAT 7. Is that all the more reason to believe "that was my bus" or...not? I've noticed some negative comments around here on CATs in general. Is that the wrong impression?

Here's the auction, just ended:

https://www.ebay.com/itm/Thomas-/113...p2047675.l2557

That is a nice looking bus. However, folks here have mixed feelings about the C7. Before you buy, Google "bulletproofing your C7"

The Allison 2000 is great.
PNW_Steve is offline   Reply With Quote
Old 11-06-2019, 01:03 PM   #11
Mini-Skoolie
 
Join Date: Oct 2019
Posts: 13
Thanks Steve. I noticed some comments on another thread about an interesting feature of the A-2000 (and I guess some previous thousand-series as well). Apparently it can be ordered with an optional 6th gear, but even if not supplied at the factory, it can apparently be accessed or "activated" by owners of existing units by following a somewhat elaborate-sounding hack. One owner wrote that, on the level in 6th gear, his bus cruises at freeway speeds with the engine essentially at an idle. That's gotta be pretty economical! Does anybody here know about that?
My Great Escape is offline   Reply With Quote
Old 11-06-2019, 01:15 PM   #12
Bus Geek
 
Join Date: May 2016
Location: Eastern WA
Posts: 5,727
Year: 2002
Coachwork: Bluebird
Chassis: All American RE (A3RE)
Engine: Cummins ISC (8.3)
Rated Cap: 72
Quote:
Originally Posted by My Great Escape View Post
Thanks Steve. I noticed some comments on another thread about an interesting feature of the A-2000 (and I guess some previous thousand-series as well). Apparently it can be ordered with an optional 6th gear, but even if not supplied at the factory, it can apparently be accessed or "activated" by owners of existing units by following a somewhat elaborate-sounding hack. One owner wrote that, on the level in 6th gear, his bus cruises at freeway speeds with the engine essentially at an idle. That's gotta be pretty economical! Does anybody here know about that?
The MD-3060 and the 1000/2000 series, post 2005 are six speed transmissions. Sixth is locked out in the programming of the TCM.

Pre 2005 1000/2000 are five speed and can be upgraded by changing out the valve body and enabling sixth in software.

I don't have sixth enabled yet and I can run close to 70 in fifth. I don't need to go any faster but I would like to run on the interstate with lower rpm's.

There is a thread dedicated to "unlocking sixth"
PNW_Steve is offline   Reply With Quote
Old 11-06-2019, 02:51 PM   #13
Bus Crazy
 
Join Date: May 2014
Location: West Ohio
Posts: 1,272
Year: 1984
Coachwork: Bluebird
Chassis: International 1753
Engine: 6.9 International
Rated Cap: 65
If you'll be living in this for weeks on end, you'll want to maximize the internal square footage available to you. So go with some sort of transit style bus vs the conventional style that you're looking at. Another perk of the transits is that they have a tighter turning radius then a conventional of the same length. That makes them more maneuverable and easier to park.

If you're 5'10" most bus offerings will be fine for you. It's when you're 6'+ that you'll have to get picky.

Look for something in the south or out west to avoid rust. Try and find buses from school districts that are in affluent areas. That makes them more likely to have better maintenance and repair performed on them, as well as having better options.

If you're planning on travelling significantly, go with the larger/higher hp engines. Check the rear gearing in any bus that you look at, that's the biggest factor in cruising speed. You'll also want one of the better transmissions too, so get one of the modern allison offerings, or at least one of the MT6XX series for the lock up torque converter.

As far as engines go. They all have problems. So if it's pre-04 I'd go with one that seem to be the best maintained, 04-07 I'd choose cummins only, and avoid anything built between 07-13
Booyah45828 is offline   Reply With Quote
Old 11-06-2019, 04:37 PM   #14
Bus Geek
 
o1marc's Avatar
 
Join Date: Dec 2017
Location: Dawsonville, Ga.
Posts: 8,456
Year: 1999
Coachwork: Genesis
Chassis: International
Engine: DT466/3060
Rated Cap: 77
Quote:
Originally Posted by My Great Escape View Post
Thanks Steve. I noticed some comments on another thread about an interesting feature of the A-2000 (and I guess some previous thousand-series as well). Apparently it can be ordered with an optional 6th gear, but even if not supplied at the factory, it can apparently be accessed or "activated" by owners of existing units by following a somewhat elaborate-sounding hack. One owner wrote that, on the level in 6th gear, his bus cruises at freeway speeds with the engine essentially at an idle. That's gotta be pretty economical! Does anybody here know about that?
An exaggeration at best. The 6th gear is in the tranny, they just electrcally disable/enable it.Ultimately the 3060 is the top tranny for an automatic. An FE has rear access an RE and more build space than a CE.
o1marc is online now   Reply With Quote
Old 11-06-2019, 04:51 PM   #15
Bus Geek
 
o1marc's Avatar
 
Join Date: Dec 2017
Location: Dawsonville, Ga.
Posts: 8,456
Year: 1999
Coachwork: Genesis
Chassis: International
Engine: DT466/3060
Rated Cap: 77
Quote:
Originally Posted by o1marc View Post
An exaggeration at best. The 6th gear is in the tranny, they just electrcally disable/enable it.Ultimately the 3060 is the top tranny for an automatic. An FE has rear access an RE and more build space than a CE.
Cruising speed may have absolutely nothing to do with gears or rear ends if governed.
o1marc is online now   Reply With Quote
Old 11-13-2019, 07:54 PM   #16
Mini-Skoolie
 
Join Date: Dec 2016
Posts: 18
Welcome to the world of owning a bus!

I own a fleet of buses and I've had quite a bit of experiencing with different specs. Here's my two cents for you:

1) Correct with the engines for IC. DT466 is a good motor. T444 is a throw away, and I wouldn't recommend for a hobbyist.

2) If you're mainly on the highway, I'd stick with an Allison MD3060. These typically come programmed for 5-speed, but 6-speed is an option. You will have better luck obtaining authorization through Thomas.

3) Allison 1000 pts / 2500 pts / AD 2000 & AD 2500 were all 5-speed mechanically prior to 6/2006.

4) If you go with an AD 2000, these transmissions had wire harnesses that ran through the transmission fluid. The harness plugs were known to leak and short. It's a good transmission, but be mindful on maintenance. I have one left in my fleet and I rebuilt it last year.

5) In reference to ratios - the indicated ratio is the number of times the drive shaft rotates per one rotation of the wheel. While a lower ratio is more fuel economical, the trade off is torque. You may have a slower bus if your ratio is smaller.

6) Ensure you have ample HP. I wouldn't go any lower than 210HP with a 230HP preferred. You will waste fuel on a low HP engine.

Hope this helps.

Jeremy
jhagan is offline   Reply With Quote
Old 11-13-2019, 07:55 PM   #17
Mini-Skoolie
 
Join Date: Dec 2016
Posts: 18
Also, I have a fleet of Cats. I have 3116, 3126 and C7. They are all good as long as you keep up with them. I have a cat pushing 400k miles with no blow by. Change oil often and ensure you have the adjunct HUEI filter.
jhagan is offline   Reply With Quote
Old 11-13-2019, 07:59 PM   #18
Bus Geek
 
o1marc's Avatar
 
Join Date: Dec 2017
Location: Dawsonville, Ga.
Posts: 8,456
Year: 1999
Coachwork: Genesis
Chassis: International
Engine: DT466/3060
Rated Cap: 77
Quote:
Originally Posted by jhagan View Post
Welcome to the world of owning a bus!

I own a fleet of buses and I've had quite a bit of experiencing with different specs. Here's my two cents for you:

1) Correct with the engines for IC. DT466 is a good motor. T444 is a throw away, and I wouldn't recommend for a hobbyist.

2) If you're mainly on the highway, I'd stick with an Allison MD3060. These typically come programmed for 5-speed, but 6-speed is an option. You will have better luck obtaining authorization through Thomas.

3) Allison 1000 pts / 2500 pts / AD 2000 & AD 2500 were all 5-speed mechanically prior to 6/2006.

4) If you go with an AD 2000, these transmissions had wire harnesses that ran through the transmission fluid. The harness plugs were known to leak and short. It's a good transmission, but be mindful on maintenance. I have one left in my fleet and I rebuilt it last year.

5) In reference to ratios - the indicated ratio is the number of times the drive shaft rotates per one rotation of the wheel. While a lower ratio is more fuel economical, the trade off is torque. You may have a slower bus if your ratio is smaller.

6) Ensure you have ample HP. I wouldn't go any lower than 210HP with a 230HP preferred. You will waste fuel on a low HP engine.

Hope this helps.

Jeremy
My experience has shown the authorization comes from Allison before Thomas or anyone else can unlock the trans.
o1marc is online now   Reply With Quote
Old 11-13-2019, 08:01 PM   #19
Mini-Skoolie
 
Join Date: Dec 2016
Posts: 18
No; the authorization comes from the OEM of the bus, then the authorization letter is released to Allison, of whom will release the calibration to your local Allison Dealer.
jhagan is offline   Reply With Quote
Old 11-13-2019, 08:05 PM   #20
Bus Geek
 
o1marc's Avatar
 
Join Date: Dec 2017
Location: Dawsonville, Ga.
Posts: 8,456
Year: 1999
Coachwork: Genesis
Chassis: International
Engine: DT466/3060
Rated Cap: 77
Quote:
Originally Posted by jhagan View Post
No; the authorization comes from the OEM of the bus, then the authorization letter is released to Allison, of whom will release the calibration to your local Allison Dealer.
Myself, and others have gotten dealers to comply, only for Allison to deny the unlock. The OEM can ask all day long, if Allison decides no, OEM can't unlock it. It's not like I haven't been through several dealers and outside resources to get mine unlocked.
o1marc is online now   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 04:24 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
×