# P42 Miles Per Gallon



## OlympianHiawatha (Feb 23, 2011)

What is the average miles per gallon for 2 P42s pulling a "typical" 9-10 car Superliner consist? I know this probably isn't a straight forward easy to calculate figure but something in the ballpark. And if 2 engines are doing the work versus 1, does each engine get "better" mileage since the load is shared?


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## henryj (Feb 23, 2011)

I have no idea. But here are some links.

http://strredwolf.livejournal.com/467957.html

http://cs.trains.com/TRCCS/themes/trc/forums/thread.aspx?ThreadID=147702&PostID=1637281&PermaPostID=1637281

Locomotives are actually rated in GPH or Gallons per Hour at each run level. So mileage would depend on how hard the engine was working and how far it went at that level. To get a good reading what you really need is fuel consumption for a particular train end to end, start to stop. Then figure out passenger capacity and get a figure that is mileage per passenger on that particular route. I know you have seen the CSX add that advertises they can haul a ton of freight 400 miles on a gallon of fuel. How far can Amtrak haul a passenger on a gallon of fuel? Interesting question.

Here is a site that tries to answer the question:

http://en.wikipedia.org/wiki/Fuel_efficiency_in_transportation

TrainsUK freight trains average about 1.5–2.0 MPG loaded. Compared with road transport it is very efficient; if lorries did the same trip they would use 70% more fuel than a freight train. UK passenger trains average from 8 MPG to 12 MPG.

Freight: the AAR claims an energy efficiency of 457 ton-miles per gallon of diesel fuel in 2008[26]

The East Japan Railway Company claims for 2004 an energy intensity of 20.6 MJ/car-km, or about 0.35 MJ/passenger-km[27]

a 1997 EC study[28] on page 74 claims 18.00 kWh/train-km for the TGV Duplex assuming 3 intermediate stops between Paris and Lyon. This equates to 64.80 MJ/train-km. With 80% of the 545 seats filled on average[29] this is 0.15 MJ/passenger-km.

Actual train consumption depends on gradients, maximum speeds and stopping patterns. Data was produced for the European MEET project (Methodologies for Estimating Air Pollutant Emissions) and illustrates the different consumption patterns over several track sections. The results show the consumption for a German ICE high-speed train varied from around 19–33 kW·h/km (68–120 MJ/km; 31–53 kW·h/mi). The data also reflects the weight of the train per passenger. For example, the TGV double-deck ‘Duplex’ trains use lightweight materials in order to keep axle loads down and reduce damage to track; this saves considerable energy.[30]

A Siemens study of Combino light rail vehicles in service in Basel, Switzerland over 56 days showed net consumption of 1.53 kWh/vehicle-km, or 5.51 MJ/vehicle-km. Average passenger load was estimated to be 65 people, resulting in average energy efficiency of 0.085 MJ/passenger-km. The Combino in this configuration can carry as many as 180 with standees. 41.6% of the total energy consumed was recovered through regenerative braking.[31]

A trial of a Colorado Railcar double-deck DMU hauling two Bombardier Bi-level coaches found fuel consumption to be 128 US gallons (480 l; 107 imp gal) for 144 miles (232 km), or 1.125 mpg-US (209.1 L/100 km; 1.351 mpg-imp). The DMU has 92 seats, the coaches typically have 162 seats, for a total of 416 seats. With all seats filled the efficiency would be 468 passenger-miles per US gallon (0.503 L/100 passenger-km; 562 passenger-mpg-imp).[32]

Note that intercity rail in the US reports 3.17 MJ/passenger-km which is several times higher than reported from Japan. Independent transportation researcher David Lawyer attributes this difference to the fact that the losses in electricity generation may not have been taken into account for Japan[33] and that Japanese trains have a larger number of passengers per car.[34]

Modern electric trains like the shinkansen use regenerative braking to return current into the catenary while they brake. This method results in significant energy savings, whereas diesel locomotives (in use on unelectrified railway networks) typically dispose of the energy generated by dynamic braking as heat into the ambient air.[citation needed]

This Swiss Railroad company SBB-CFF-FFS cites 0.082 kWh per passenger-km for traction.

AEA carried out a detailed study of road and rail for the United Kingdom Department for Transport. Final report

Amtrak reports 2005 energy use of 2,935 BTU per passenger-mile (1.9 MJ/passenger-km).[35]

The Passenger Rail (Urban and Intercity) and Scheduled Intercity and All Charter Bus Industries Technological and Operational Improvements - FINAL REPORT states that "Commuter operations can dissipate more than half of their total traction energy in braking for stops." and that "We estimate hotel power to be 35 percent (but it could possibly be as high as 45 percent) of total energy consumed by commuter railways."[36] Having to accelerate and decelerate a heavy train load of people at every stop is inefficient despite regenerative braking which can recover typically around 20% of the energy wasted in braking.

US Passenger transportationThe US Transportation Energy Data Book states the following figures for Passenger transportation in 2006:[42]

Transport mode Average passengers

per vehicle BTU per passenger-mile MJ per passenger-kilometre

Vanpool 6.1 1,322 0.867

Efficient Hybrid 1.57 1,659 1.088

Motorcycles 1.2 1,855 1.216

Rail (Intercity Amtrak) 20.5 2,650 1.737

Rail (Transit Light & Heavy) 22.5 2,784 1.825

Rail (Commuter) 31.3 2,996 1.964

Air 96.2 3,261 2.138

Cars 1.57 3,512 2.302

Personal Trucks 1.72 3,944 2.586

Buses (Transit) 8.8 4,235 2.776

Looks like Vanpool is the most efficient form of transport. Amtrak rates fourth.


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## Ryan (Feb 23, 2011)

Should be pretty easy to figure, you can read the fuel remaining on digital gauges on the side of the locomotive. Check it between two stops and you can calculate it pretty easy.


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## transit54 (Feb 23, 2011)

Amtrak lists gallons per train mile in their performance reports, which can be obtained here:

http://www.amtrak.com/servlet/ContentServer?c=Page&pagename=am%2FLayout&cid=1241245669222

Based on the Dec 2010 report (the most recent) trains average between 2.2 and 2.5 gallons per train mile. In the figures your looking for, that would be between .4 and .46 miles per gallon.


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## Acela150 (Feb 23, 2011)

So a P42 goes less then half a mile on a gallon of diesel fuel?? WOW! That's crazy on how short of a distance it goes. I would think at least two miles. I was wrong. :lol:


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## the_traveler (Feb 23, 2011)

But how many MPGs does it get on 89 octane unleaded gas?


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## Trogdor (Feb 24, 2011)

Acela150 said:


> So a P42 goes less then half a mile on a gallon of diesel fuel?? WOW! That's crazy on how short of a distance it goes. I would think at least two miles. I was wrong.


Given how large the engine is and how much power it puts out, I don't know why you would expect it to get any more than that.

The real measure of fuel efficiency isn't miles per gallon, it's payload-miles per gallon (passenger-miles or ton-miles, as the case may be). A P42 getting 0.4 miles per gallon pulling a train with 100 passengers gets 40 passenger-miles per gallon. That's certainly better than most single-occupancy cars out there. Put 400 people on a train (a full Hiawatha, for example), and you get 160 passenger-miles per gallon.


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## Green Maned Lion (Feb 24, 2011)

the_traveler said:


> But how many MPGs does it get on 89 octane unleaded gas?


Zero. Putting 89 Unleaded into a P42 would create damage to its valve gear and fuel delivery systems, not to mention its block, pistons, etc. that would cost, I would guess, hundreds of thousands of dollars to fix. You would, in all likelyhood, need to replace the entire prime mover.


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## transit54 (Feb 24, 2011)

To put more numbers to it, from the Nov 2010 report (it's in December's report also, I just happened to have Nov 2010 in front of me), Amtrak used 2.2 gallons per train mile and traveled 3,129,000 train miles during the month of November. During that time they accumulated 528,450,000 passenger miles. That works out to 76.8 passenger miles per gallon.

Amtrak actually had 1,081,300,000 seat miles available during November. So if every seat was sold out on every Amtrak train each day, Amtrak could theoretically obtain 157.1 passenger miles per gallon.

Now, granted, this assumes that all trains involved were diesel, which they were not - thus the actual efficiency could vary if electric trains were more fuel efficient, for instance. But these numbers at least give a back of the envelope estimate of Amtrak's efficiency in comparable terms.


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## jis (Feb 24, 2011)

henryj said:


> US Passenger transportation - The US Transportation Energy Data Book states the following figures for Passenger transportation in 2006:[42]
> 
> Transport mode Average passengers
> 
> ...


Interesting! It uses the following interesting parameters for average number of passengers per vehicle to do its what appears to be questionable conclusions:

Van pool 6.1 - a very tightly packed van

Rail (Intercity) 20.5 - a very sparsely used train

Rail (Transit Light and Heavy) 22.5 - clearly we are not talking new York Subway or even HBLRT here

Rail (Commuter)31.3 - again we are not talking of LIRR, MNRR or NJT here.

Buses (Transit) 8.8 - maybe they should replace those routes with the tightly packed vans 

Isn't number crunching fun? I have no doubt that all of that calculation is based on some real set of numbers spanning all transport everywhere in US. But the numbers are somewhat useless as a means for planning anything.


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## the_traveler (Feb 24, 2011)

jis said:


> henryj said:
> 
> 
> > Transport mode *Average passengers per vehicle* BTU per passenger-mile MJ per passenger-kilometre
> ...


I'd hate to meet that .1 passenger!



(Maybe it was too tightly packed!



)


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## Bigval109 (Feb 24, 2011)

Acela150 said:


> So a P42 goes less then half a mile on a gallon of diesel fuel?? WOW! That's crazy on how short of a distance it goes. I would think at least two miles. I was wrong. :lol:


Well let us remember it isn't a car. :blink: In fact the engine weighs maybe 100,000 lbs plus the weight of the cars behind it. It has 16 cylinders or maybe 12 and each cylinder is the size of maybe a washing machine just a guess. I think it does good to get that much. I use to have a 455 olds that only got 8 mpg. :wacko: I was always crying at the gas station and gas was only .25 a gallon back in 1972. but it didn't last long in that Olds. The car was great though. I certainlly could use some .25 gallon gas today.


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## the_traveler (Feb 24, 2011)

Bigval109 said:


> I certainlly could use some .25 gallon gas today.


Eat lots of baked beans - and you'll have plenty of gas!


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## George Harris (Feb 25, 2011)

jis said:


> Interesting! It uses the following interesting parameters for average number of passengers per vehicle to do its what appears to be questionable conclusions:
> Van pool 6.1 - a very tightly packed van
> 
> Rail (Intercity) 20.5 - a very sparsely used train
> ...


Exactly right: This sort of stuff is an outstanding example of the saying, "Figures don't lie, but liars figure."

If you changed the passenger count to realistic figures, the results would be completely different. Back in the 1960's passenger trains with higher than 20.5 average passenger counts were permitted be discontinued by the ICC.


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## Trogdor (Feb 25, 2011)

Well, the stats do say "passengers per vehicle" not "passengers per train." I'm not sure what counts as a vehicle in this case, but if you have seven cars and a locomotive, does that count as eight vehicles? A train with a locomotive, a baggage car, dorm car, one sleeper, dining car, lounge, and two coaches might have 160 people on it, but it's entirely possible that these stats would say that "passengers per vehicle" would be 20.


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## PRR 60 (Feb 25, 2011)

The intercity rail energy stats published by the DOE, including ridership, come directly from Amtrak. Many, if not most formal van pools use 12 passenger vans, so a count of 6.1 per van is only 50% occupancy.

The DOE report has a pretty comprehensive discussion of the basis for ridership figures and assumptions. The figures are not just pulled out of thin air.


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## jis (Feb 25, 2011)

PRR 60 said:


> The intercity rail energy stats published by the DOE, including ridership, come directly from Amtrak. Many, if not most formal van pools use 12 passenger vans, so a count of 6.1 per van is only 50% occupancy.
> 
> The DOE report has a pretty comprehensive discussion of the basis for ridership figures and assumptions. The figures are not just pulled out of thin air.


I specifically said that I completely believe that they were based on concrete data. All that I said is they are not particularly useful for planning a specific system since the range of systems from which data was rolled up for it made it somewhat useless for the purposes of planning a specific system, or even coming to any conclusion on how future policy execution would change these parameters.

In the same spirit, Amtrak system-wide data is not particularly useful in determining what the energy consumption profile is for NEC for example.

Your point about 12 seat van is well taken.

BTW there are some obvious factors that weigh in against American passenger trains being as energy efficient as those elsewhere. For example, American trains tend to have some of the lowest seat densities and some of the highest tare weight per seat that has to be carted around, of any trains in the world. That has negative impact on energy efficiency.


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## andrew (Mar 17, 2015)

how far can a train go on fuel? like how many times would the locomotives on the Sunset Limited or Empire Builder need a fill up?


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## BCL (Mar 17, 2015)

andrew said:


> how far can a train go on fuel? like how many times would the locomotives on the Sunset Limited or Empire Builder need a fill up?


A P42DC has a 2200 gallon tank. I'm guessing that both segments of the Empire Builder can go the entire route without refueling. I think the California Zephyr or Texas Eagle are longer and won't require a fuel stop.

As far as the fuel goes, I thought it was No. 2 fuel oil. Someone told me that it's practically identical to No. 2 diesel except for the addition of a red dye to indicate that it wasn't taxed as a road fuel. The dye is supposed to indicate that it was used illegally if found in an over the road truck.


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## Paulus (Mar 17, 2015)

Amtrak's diesel trains average 2.3 gallons per mile.


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## CCC1007 (Mar 17, 2015)

I know that Amtrak refuels in havre, mt.


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## KmH (Mar 17, 2015)

Yep. That's why each P42DC locomotive has 2200 gallon fuel tanks.



Bigval109 said:


> 'Acela150' said:
> 
> 
> > So a P42 goes less then half a mile on a gallon of diesel fuel?? WOW! That's crazy on how short of a distance it goes. I would think at least two miles. I was wrong.
> ...


The P42DC prime mover engine has a V configuration diesel with 16 cylinders and each cylinder has a displacement of 10.95 liters (668 cu in). Total displacement is 175.2 liters (10,690 cu in.).

I think the CZ refuels in Denver going each way, and start full at each end of the route.

Don't forget that some of the fuel used goes to making Head End Power (HEP) of up to 800 Kw of electrical power for the train.
Traction motor HP is decreased as more HEP is produced.



> All Genesis engines can provide head-end power (HEP) to the train drawn from an alternator or inverter powered by the main engine at a maximum rating of 800 kilowatts (1,100 hp), making each unit capable of providing HEP for up to 16 Superliner railcars. The P40DC and P42DC power plants can supply 60-hertz head-end power either from the HEP alternator with the engine speed-locked to 900 rpm (normal mode) or from the traction alternator with the engine speed-locked to 720 rpm (standby mode). In the latter case, traction power is unavailable.


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## VentureForth (Mar 17, 2015)

Southwest Chief refuels in ABQ.


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## CCC1007 (Mar 17, 2015)

The numbers indicate just under 1000 miles for their range.


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## DryCreek (Mar 17, 2015)

Green Maned Lion said:


> 'the_traveler' said:
> 
> 
> > But how many MPGs does it get on 89 octane unleaded gas?
> ...


Actually, no. Diesel engines run on compression-ignition fuels which and are rated in cetane numbers, whereas spark-ignition fuels are rated in octane. I live where diesel engines are very popular, and we own two diesel pickups and two diesel tractors. I have seen what happens when an unwitting person fills their tank with gasoline instead of diesel. The engine just stops. Lighter distillates won't combust in a standard compression ignition engine*. What we've had to do to fix the problem of wrong fuel is simple - you siphon out as much of the gasoline as you can, and refill the tank with diesel, and maybe throw in a gallon or two of TC-3 two stroke oil to slick up the injection pump internals. In most cases, the lack of lubricity in the gasoline isn't a problem as the engine doesn't run long enough to screw up the lift pumps, the injectors or the injection pump.

*** there are/were hybrids known as "Distillate Engines" that ran on both fuels, albeit not very efficiently.


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## Ryan (Mar 17, 2015)

CCC1007 said:


> I know that Amtrak refuels in havre, mt.


Minot as well.


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## BCL (Mar 17, 2015)

KmH said:


> The P42DC prime mover engine has a V configuration diesel with 16 cylinders and each cylinder has a displacement of 10.95 liters (668 cu in). Total displacement is 175.2 liters (10,690 cu in.).


http://www.salvex.com/listings/listing_detail.cfm?aucID=182946333

Says they're 6 feet wide and 8 feet high. I'm guessing salvaged from freight locomotives. These three look like the turbos are in front.


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## amtkstn (Mar 17, 2015)

The Chiefs get their locomotives topped east of KC in the rail yard.


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## Guest (Mar 17, 2015)

BCL said:


> andrew said:
> 
> 
> > how far can a train go on fuel? like how many times would the locomotives on the Sunset Limited or Empire Builder need a fill up?
> ...


Don't know about railroad, but the red dye is put into diesel sold for farm use and delivered to the farm by tank truck.


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## BCL (Mar 17, 2015)

Guest said:


> BCL said:
> 
> 
> > andrew said:
> ...


This company lists six different fuel oils dyed red. One is "Grade No. 2 Diesel S-500 Dyed L-M", where that stands for locomotive-marine.

http://www.amref.com/products/fuels.aspx


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## Bob Dylan (Mar 17, 2015)

The Texas Eagle ( One P-42) refuels in Ft. Worth and St. Louis on its run between Chicago and San Antonio. On one trip they "forgot" to refuel and we had to wait in Taylor for 2 hours for a fuel truck to refuel us!!

The SWC ( 2 P-42s)fuels up, as was said, in Albuqurque, and WEST of Kansas City in the freight yard on its run between LA and Chicago.

The Sunset Ltd.(2 P-42s) fuels up in San Antonio, El Paso, and if needed, in Tucson between NOL and LAX.


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## KmH (Mar 17, 2015)

BCL said:


> KmH said:
> 
> 
> > The P42DC prime mover engine has a V configuration diesel with 16 cylinders and each cylinder has a displacement of 10.95 liters (668 cu in). Total displacement is 175.2 liters (10,690 cu in.).
> ...


Yep. They are big.

I was quoting the displacement of the cylinders, not the outer dimensions of of the engine.


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## Thirdrail7 (Mar 17, 2015)

OlympianHiawatha said:


> What is the average miles per gallon for 2 P42s pulling a "typical" 9-10 car Superliner consist? I know this probably isn't a straight forward easy to calculate figure but something in the ballpark. And if 2 engines are doing the work versus 1, does each engine get "better" mileage since the load is shared?


I would think the engine that is using HEP would expend more fuel than one that is used purely for traction power, particularly in lower throttle positions. Additionally, there are strict(?) policies about how many units are allowed online at any given time for traction power. At other times, they must be isolated.


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## KmH (Mar 17, 2015)

Paulus said:


> Amtrak's diesel trains average 2.3 gallons per mile.


Since Amtrak doesn't haul freight, lets think of the mileage in terms of people.

On a LD train - Engineer, Conductor, Assistant Conductor, OBS staff, - LSA Diner, Chef, Food Specialists, SA, LSA - Cafe/Lounge, 1 Train Attendant- Coach (TAC), 3 Train Attendant - Sleeper Car (TASC). Say 14 people.

Lets say 30 pax per sleeper car w/3 sleeper cars or 90 pax,

and close to 2 of 3 coach car seats filled for 150 coach pax.

14 + 90 + 150 =255 people moved by 2.3 gallons of diesel fuel per mile.

That's 0.009 gallons per person, per mile or 100 mpg per person.

Lets drop the employees and just consider 240 passengers - 2.3 gpm = 0.00906 gpp or 95.8 mpg/person.

Oh! And with 2 P42DC engines, a LD train has 32 cylinders for power, motive and/or HEP.

By the way. 255 people at an average weight of 180 each + 50 lbs of baggage = 56,100 lbs (28.05 tons)

Does anyone know what the airlines use as the average weight figure for people these days?


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## Alexandria Nick (Mar 18, 2015)

KmH said:


> Does anyone know what the airlines use as the average weight figure for people these days?


170(!), but they're talking about revising that way, way up. I hear conjecture it could hit 215.


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## battalion51 (Mar 18, 2015)

Thirdrail7 said:


> OlympianHiawatha said:
> 
> 
> > What is the average miles per gallon for 2 P42s pulling a "typical" 9-10 car Superliner consist? I know this probably isn't a straight forward easy to calculate figure but something in the ballpark. And if 2 engines are doing the work versus 1, does each engine get "better" mileage since the load is shared?
> ...


Running HEP is equivalent to running in the 6th notch (of 8) all the time. There is obviously fuel being spent to provide HEP versus just running for traction.


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## Shortline (Mar 18, 2015)

BCL said:


> andrew said:
> 
> 
> > how far can a train go on fuel? like how many times would the locomotives on the Sunset Limited or Empire Builder need a fill up?
> ...


Just between San Antonio and Chicago, the TE is refueled at FTW and STL.


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## VentureForth (Mar 18, 2015)

battalion51 said:


> Thirdrail7 said:
> 
> 
> > OlympianHiawatha said:
> ...


Without looking, I believe it is 170 for crew and 190 for pax.
That seems like excessive consumption. With two locos, it's 98 mpg per pax? Or with one? If only one, then we're looking at 50 mpg per pax when two locos are used (disregarding efficiencies) which ain't that great and comes close to what I get on the highway in my gasoline powered Suburban with my family.


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## KmH (Mar 18, 2015)

Paulus said:


> Amtrak's diesel trains average 2.3 gallons per mile.


I was calculating by 'train', not per locomotive.


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