Author Topic: interstate crusin speed?  (Read 6183 times)

Offline lostagain

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Re: interstate crusin speed?
« Reply #15 on: November 03, 2013, 11:38:39 AM »
Jeremy, correct me if I am wrong, but aren't all transport trucks and buses limited to 90 km/h (55mph) all over Europe? Is it more for safety, or economy?

Blackie AB
1977 MC5C, 6V92/HT740

Offline HB of CJ

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60 MPH At 1500 RPM In 10th Gear
« Reply #16 on: November 03, 2013, 12:57:20 PM »
1500 RPM seemed to be the sweet spot with the Big Cam Cummins pancake engine.  Since the Crown Supercoach only got to go on just a handful of meaningful road trips, the remembered fuel mileage is hazzy, but probably was between 10 and 11 mpg.  Crowns are kinda aerodynamic....up to a certain speed.  HB of CJ (old coot)

Offline white-eagle

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Re: interstate crusin speed?
« Reply #17 on: November 03, 2013, 01:20:24 PM »
my sweet spot is around 70.  much slower and the rpms are too low for the next hill.  middle lane in towns to avoid the constant move out of the way of entering cars.  i try to avoid the "crumple zone" Bob otn mentioned by backing off from the idiots when i can, and like he said, i look for my best option direction, just in case.
in the flat states, 65 can become 75 pretty quick if i'm not watching close enough.  i try to pay attention because Fran gets upset if i have to brake and it dumps plants, etc.
1991 Eagle 15 and proud of it.
8V92T, 740, Fulltime working on the road.

Fran was called to a higher duty 12/16/13. I lost my life navigator.

Offline Oonrahnjay

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Re: interstate crusin speed?
« Reply #18 on: November 03, 2013, 02:45:52 PM »
  ...  logging trucks.   They are crazy... 

     That seems to be true everywhere.   
Bruce H; Wallace (near Wilmington) NC
1976 Daimler (British) Double-Decker Bus; 34' long

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Offline roadrunnertex

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Re: interstate crusin speed?
« Reply #19 on: November 03, 2013, 02:57:31 PM »
My P8M4905A with a 8V/71 & V730 transmission does real well at 60 to 65 mph on the interstates in Texas and the Southeast.
6 to 6.5 mpg on the last trip with R.J.Long as the driver and I the co-pilot.
It's to bad fuel is almost $4.00 per gallon but that is the way it's going to be for us diesel powered folks.
Back many years ago when Greyhound had real buses and real bus drivers who use to drive the Silversides and the PD4104's and the PD4501 Scenicruisers. My dad was driving for Greyhound and there were no interstates in Florida he used to drive 60-65 mph and do just fine.
To this day I can still hear him say keep it between 60&65 MPH son and you will do just fine.
I wish he was still around to see how the industry has changed.

Offline RJ

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Re: interstate crusin speed?
« Reply #20 on: November 03, 2013, 09:54:53 PM »
My P8M4905A with a 8V/71 & V730 transmission does real well at 60 to 65 mph on the interstates in Texas and the Southeast.

What John forgot to mention here is that we were fighting a cross-headwind the entire trip from TX to the Blytheville gathering, where we fueled before we left.  (And had a GREAT time, too!)

Calm weather for the trip back to TX, so mileage might be better, we'll see when the numbers come in.

4905s are in "the sweet spot" for ride, handling, noise and comfort at about 65 +/- a couple mph.

FWIW & HTH. . .

RJ Long
PD4106-2784 No More
S13406 1978 MC-5C Converted 6V71/MT-644
S14947 1980 MC-5C Shell 6V92/HT-740
Cheney WA

Offline Mike in GA

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Re: interstate crusin speed?
« Reply #21 on: November 04, 2013, 01:54:37 AM »
Ultimately we must do what we are personally comfortable doing, since few of our rigs are similar and our ages and driving abilities vary.
     For me, I like to run about 2000-2100 on the tach, the bus's sweet spot, which on the flat is 62-64 mph, no headwind.
     I prefer to travel in the right lane, unless in a city with lots of on-ramps. Here are my reasons:
1. I like having the breakdown lane immediately available if I should develop a sudden mechanical problem;
2. I can jump into the breakdown lane if someone stops short in front of me. And I have used it, in the blink of an eye;
3. My speeds are slower than most, and I don't want to clog the middle or the passing lanes, hold up other motorists or force some right-lane passing;
4. In my advanced age (69 two more days) I confess that my planned exit ramp occasionally sneaks up on me, and I can get to it easily from the right-most lane. (I realize that this rarely happens to other readers!).
     An old professional driver in our Bus Nuts group who has been full timing for 20 years encouraged me to start busin' by using the right hand lane, for safety and to allow myself to get used to driving a big rig with tow car, whose bus cannot and will not stop as quickly as the cars I was used to. I followed his advice and haven't changed much after 13 years of fun.
     Just my way. YMMV.
Mike in GA
Past President, Southeast Bus Nuts. Busin' for more than 15 years in a 1985 MC 96a3 with DD 8v92 and a 5 speed Allison c/r.

Offline Jon

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Re: interstate crusin speed?
« Reply #22 on: November 04, 2013, 04:21:10 AM »
I drive slow. I expect folks to nod their heads and tell me I am dangerous, a rolling road block, and any other descriptors to let me know I am a road hazard. But the reality for me is my coach is a RECREATION VEHICLE. I'm a 62 MPH driver in states whose typical posted highway speeds are either 65 or 70.

During a typical day of driving I will pass several vehicles per hour, but for the most part I will be passed by everyone else. I will pass certain company trucks whose speeds are likely governed. I will pass motorhomes and RVers with trailers and the occasional car. But typically I can set my cruise control and just relax knowing I am not going to have to be on and off cruise control because I am running up on the back of vehicles and need a lane change. For me driving like this is as relaxing as sitting in the living room chair.

My biggest concern is not how fast I come up on someone, but how to prevent the idiots from getting run into by me. Like everyone else I have the same fools pull in too close and then hit the brakes because they need to get off at the exit, or who don't know how to merge due to lane closures, or who just suddenly have a rain drop hit the windshield.

At that speed my Series 60 is turning 1500. most hills won't affect me, but if I sense a grade that might prove an issue I just downshift prior to getting there so I don't lose speed.

I ran quite a few miles with a friend whose preferred speed was 70. The bus was happy there also, but I had to change lanes a lot more often because I was passing a lot more vehicles, I was on the brakes more, and I was on and off the cruise control. Driving was less relaxing and not a lot of fun. But worse, I know the stopping distances required to save the lives of the idiots increased dramatically so I was never enjoying the ride.

Current coach 2006 Prevost, Liberty conversion
Knoxville, TN

Offline Jeremy

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Re: interstate crusin speed?
« Reply #23 on: November 04, 2013, 04:42:08 AM »
Jeremy, correct me if I am wrong, but aren't all transport trucks and buses limited to 90 km/h (55mph) all over Europe? Is it more for safety, or economy?


Sorry, only just seen this question. This is one of things where, despite laws supposedly being homogenized all across Europe, each country still manages to keep the same speed limits it's always had (and Britain, speeds and distances on roadsigns are still shown in imperial, despite the fact that the country went metric 50 years ago).

In Britain the speed limit for trucks on multi-lane roads is 60mph and for buses it is 70mph. On single-lane roads it is 50mph and 60mph respectively. Buses and cars have the same limit here, and for example buses are allowed in the third lane on motorways, which trucks are not. Cars generally run at around 85mph on the motorway here, which is considered acceptable, and it used to be that coaches did too - but there was a series of accidents a few years ago which put a lot of bad publicity onto the coach industry and they rarely break the limits now (and, as I said in another thread, my own bus has a speed limiter). Until earlier this year (when the environmentalists got in the way) the Government was proposing 85mph as the new limit for UK motorways, but I imagine that if that did ever happen that they would introduce a lower limit for buses (and I'm sure that would be the correct thing to do).

I'm not sure about limits in other countries but I think the 90kph for trucks that you mentioned is widespread because a lot of foreign trucks that you see here have '90' symbols on the back. But whether that applies to buses and coaches I'm not sure. I do know from driving in France for instance that their motorway signs have two speed limits posted, one for when the road is dry and one for when it is wet - which has always seemed incredibly sensible to me


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Offline robertglines1

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Re: interstate crusin speed?
« Reply #24 on: November 04, 2013, 05:48:34 AM »
To be clear:: I have always believed one should drive their own race!  Drive to their abilities and equipment.  I just felt that the general attitude presented on the boards is/was that if you didn't drive 55 to 60 in the right hand lane ==your doing it wrong.  Not saying anyone  change!   Stay safe==  will be proud to run with you at any speed.   Not past my limit! ? unknown in new ride?   Bob
« Last Edit: November 04, 2013, 05:52:26 AM by robertglines1 »
Bob@Judy  98 XLE prevost with 3 slides --Home done---last one! SW INdiana

Offline Bill B /bus

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Re: interstate crusin speed?
« Reply #25 on: November 05, 2013, 04:42:01 PM »
First bus was a PD4108. Sweet spot was 72 to 75 MPH. Mileage was 8 to 8.3 MPG. That was a little faster than I wanted to run. Changed tires to 11/22.5. Sweet spot moved to 66 to 70 MPH. Mileage improved to 8.5+ MPG.

Second bus is an MCI102A3 with a Series 50 and an HT70 transmission with a .75 overdrive. Happy spot is around 62-67 MPH. Fuel mileage is running around 8.5 to 9 MPG. Last tank was 9.6 MPG. So I quite happily drive in 62-65 MPH range. Going that speed north on I81 I was with traffic in the right lane and occasionally passing trucks running 60 MPH.

I will agree that sometimes traffic demands a higher or lower speed to prevent being the rock in the road or trying to force a way through. The Northeast is an example of a higher speed required to flow with the traffic.

Since we try to stay off the Interstate as much as possible our speed works.

Bill & Lynn
MCI102A3, Series 50 w/HT740

Offline wg4t50

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Re: interstate crusin speed?
« Reply #26 on: November 05, 2013, 04:55:12 PM »
The most aerodynamic bus I have any experience with is the old Senicruiser, my MC7 needed slight fuel to go down a specific moutain, why the Senecrusier needed use of brakes on same mountain. That was an eye opener for me.  He never got good fuel mileage due to running a 8V-92 with 150 injectors RTO910, 4.10, 10R22.5 and 2650 RPM and driving about 80 mph most time, yes he lost license many times, but could not put it together. After one short trip with him, I never allowed a repeat, yes there is such a thing as CRAZY.
MCI7 20+ Yrs
Foretravel w/ISM500
WG4T CW for ever.
Central Virginia