All,
While the discussion thus far has centered on vehicle engines and driver behavior, the third variable should not be lost: fuel.
The current focus on mitigating the environmental impacts of vehicle emissions has led to fuel constructs that are less optimized for energy production, from what I've been told. Have the trade-offs between less polluting fuel mixtures and energy production impacts associated with these mixtures been evaluated thoroughly and documented? This is not a rhetorical question; it's a bit out of my lane and something I am genuinely curious about.
Tom Kearney
FHWA-HOFM
(518) 431-4125 ext. 218
[log in to unmask] <mailto:[log in to unmask]>
________________________________
From: Technical, operational and economic aspects of road freight transportation on behalf of John de Pont
Sent: Tue 2/1/2011 9:35 PM
To: [log in to unmask]
Subject: Re: January 2011 Newsletter
Hi Anders,
I find your comments very interesting. They imply that the fuel savings reported by Erik is his Melbourne paper from reducing engine power were primarily the result of limiting the peak power available to the driver during hill climbing, acceleration from rest etc. Is this correct?
John
From: Technical, operational and economic aspects of road freight transportation [mailto:[log in to unmask]] On Behalf Of Lundström Anders A
Sent: Wednesday, 2 February 2011 11:27 a.m.
To: [log in to unmask]
Subject: SV: January 2011 Newsletter
John and all,
the rated power that you usually see on the cabs of heavy duty vehicles is
not an adequate measure of actual fuel consumption, I am doubtful it should be
there at the first place. Truck diesel engines in the range 200 hp and upwards are
pretty similar in terms of gram of fuel per kWh at the flywheel, i.e. similar thermal
efficiency. So it is really all about how the truck is used, in terms of traction force
and speed.
A 40 or 60 tonnes combination has a power to mass ratio approximately
a factor of ten less than that of an ordinary car. In fact, most of us "smooth" car
drivers could do very well with a 30 to 40 hp rated engined car. Will we?
Smoot driving is by far the lowest hanging fruit for fuel consumption reduction
for commercial vehicles as well as for passenger cars. Training, proper instructions,
vehicle support functions have 10 to 20 % reduction potentials. There is at least
anecdotical evidence that female commercial drivers are better fuel savers as
well as safer and resulting in lower vehicle R&M costs. Research needed?
I do not believe in the delivery time versus vehicle speed importance. Nighttime
fruit and vegetables delivery from Hastings on the east coast of the NZ North Island
to the distributers in Auckland is a matter of planning. Loading the truck was so
late and slow that the driver could have started at least one hour earlier. I know,
I was there standing waiting with my topography measuring gear. Unloading, on
the other hand, was pretty quick and on time. Do not blame the drivers.
All the best
Anders
________________________________
Från: Technical, operational and economic aspects of road freight travey nsportation [[log in to unmask]] för John de Pont [[log in to unmask]]
Skickat: den 1 februari 2011 21:44
Till: [log in to unmask]
Ämne: Re: January 2011 Newsletter
Hi Pete,
I think the truck does need adequate power to undertake its task but being over-powered uses additional fuel. The paper by Dahlberg referred to in the original post reduced the engine power from 440hp to 400hp to achieve the 3.4% fuel consumption reduction. I have no doubt that using an under-powered engine where it is not possible to use fuel-efficient driving techniques and still maintain adequate speed is also not fuel-efficient.
John
From: Technical, operational and economic aspects of road freight transportation [mailto:[log in to unmask]] On Behalf Of peter lynch
Sent: Tuesday, 1 February 2011 11:30 p.m.
To: [log in to unmask]
Subject: Re: January 2011 Newsletter
Well, do more powerful trucks use more fuel? I spent years driving totally underpowered vehicles that had to be pushed hard to make any progress.
Regards Pete
--- On Tue, 1/2/11, Craig Silby <[log in to unmask]> wrote:
From: Craig Silby <[log in to unmask]>
Subject: Re: January 2011 Newsletter
To: [log in to unmask]
Received: Tuesday, 1 February, 2011, 6:09 PM
Hi John, thanks for your discussion interest,
I am also from NZ and deal with heavy commercial vehicle purchasing and specification daily. It is my experience the majority look at the front end cost only of most items, which does not give a true picture of the actual cost in most areas of their businesses. It is very difficult to explain to the bean counters how; greater resources put into training and vehicle selection now will potentially save resources over time vs buying and hiring the cheapest on any given day.
David Potter (Axis Intermodal) explained very well at the last IRTENZ conference that putting greater resource into training, health/safety and vehicle selection/design paid many ongoing dividends to the DHL business in the UK. The greatest area I see benefits are; the reduced downtime for both staff and vehicles when training, health/safety and good vehicle selection/design are implemented. Downtime would have to be one of the most costly items a transport business faces.
Is there a web based forum application more suited to open discussions such as this? it could be very useful
Regards,
Craig Silby
www.easytrucks.co.nz <http://www.easytrucks.co.nz/>
On 1 February 2011 13:54, John de Pont <[log in to unmask] <https://webaccess.scania.com/owa/,DanaInfo=webmail.scania.com,SSL+UrlBlockedError.aspx> > wrote:
Dear IFRTT Forum subscriber
Greetings and best wishes for the New Year from the antipodes.
In the past this forum has been used to discuss technical issues of interest to, at least, some of the subscribers. In recent times, apart from the monthly newsletters, it has become primarily a bulletin board for advertising conferences, courses and jobs. While this function is important and useful I think it is a shame that the forum's role in promoting discussions and exchanges of ideas has declined. So to try to promote some revival of the discussion function I thought I would present a few ideas on an issue that subscribers may agree or disagree with in the hope that you will express your views in responses via the forum.
Current concerns about climate change are driving substantial efforts to reduce greenhouse gas emissions and the most obvious step is to improve fuel efficiency. Recent weather events in various part of the world have heightened these concerns. Even if you don't accept the climate change argument it is indisputable that fossil fuels are a finite resource and we owe it to future generations not to waste this resource. Although the vehicle manufacturers are putting substantial resources into technological solutions to address the issue, there are a number of measures that can be implemented right now using existing technology that can have a significant impact on fuel consumption.
For light vehicles the most obvious measure is downsizing the vehicles. In New Zealand (and in many the other countries) the average size of vehicles has steadily increased over the years and as a result the benefits of the fuel efficiency gains achieved by the manufacturers have been partially eroded. In New Zealand the average vehicle occupancy is 1.6 people and the maximum speed limit is 100km/h. Both of these requirements are easily accommodated by the smallest cars on the market so why are there so many larger cars? Safety is a factor. Although many small cars have excellent safety performance, the barrier crash tests effectively simulate a collision with an identical vehicle. If a small car collides with a substantially larger car Newtonian mechanics dictate that the occupants of the small car will experience greater decelerations and are more likely to suffer injuries even if the safety performance of the small car is inherently better than that of the large car. If everybody else drives a small car you are much safer in a large car. However, safety is not the only factor. The most popular large car in New Zealand is available with either a V6 or a V8 engine. The two vehicles are the same size and virtually identical in appearance but the V8 option is 24% more powerful and uses nearly 26% more fuel. The V6 option has more than enough power for the vehicle to perform its functions yet a significant proportion of sales are for the V8 option. Why?
With heavy commercial vehicles, paradoxically, both upsizing and downsizing can improve fuel efficiency. Upsizing through increasing vehicle size and weight limits reduces the amount of fuel required per tonne-km of payload. Various initiatives are in progress in different jurisdictions and we will not discuss these further here. However, for a given transport task there are fuel efficiency opportunities in better matching the engine power and transmission configuration to the transport task. Erik Dahlberg presented a paper on this topic at our last symposium in Melbourne with an example that showed a fuel efficiency gain of 3.4% compared to the standard vehicle used for the task. Generally this means downsizing the engine power. In New Zealand the maximum allowable gross combination weight for general access is 44 tonnes and this has not changed for more than 20 years. The speed limit for heavy vehicles is 90km/h. 20 years ago the typical maximum weight combination had a 350-450hp engine. Today the typical engine power for new 44 tonnes vehicles is 500-600hp. The New Zealand roading environment is relatively hilly and so there are potential travel time benefits from increased engine power. However, I believe these are overstated as we will see in the next paragraph.
The other way in which substantial gains in fuel efficiency can be achieved is through driver training. Last year the New Zealand Ministry of Transport sponsored the development and introduction of a driver training programme for fuel efficiency called SAFED-NZ (Safe and Fuel Efficient Driving). This programme is based on a similar programme of the same name developed in the UK and the introduction to New Zealand involved getting one of the developers of the UK programme to come to New Zealand to train a group of senior driving instructors. These senior driving instructors will both deliver the programme and train other driving instructors on how to deliver the programme. The basic principles of the SAFED driving are very simple and one would think obvious to any experienced driver. Yet even this very experienced group of driver trainers achieved an average improvement in fuel efficiency of 5% from undertaking the course. This is based on before and after measurements on a 40km test circuit. Significantly the average travel time for the "after" circuit was 6% less than that on the "before" circuit. That is, not only did the drivers use less fuel (and by implication less average engine power) they also achieved a higher average speed. This result is based on a very small sample and cannot be generalised but it does suggest that the negative impacts on travel time of a fuel efficient driving style and lower engine power will be small.
Although these savings in fuel consumption may appear quite modest they have a substantial impact on profitability. In New Zealand there is no road tax on diesel (road user charges are collected separately) and so fuel is relatively cheap. Nevertheless, depending on the type of transport operation, fuel represents 15-20% of total costs. In countries that collect road user charges through fuel tax it will be significantly higher proportion (perhaps double). A 5% reduction in fuel consumption can increase profits by about 1% of turnover. Trucking in New Zealand is a very competitive business and many operators' profits are less than 5% of turnover, hence this represents a 20% increase in profit, which is very significant.
With an economic incentive of this magnitude we might expect an immediate large scale uptake of these measures by the industry but this has not happened. A number of operators here have seen the opportunities and are implementing driver training for fuel efficiency programmes and looking at vehicle selection policies but many others are not. This raises the obvious question; why not? My personal view is that they don't believe the results apply to them. Specifically they don't believe that their drivers can reduce their fuel consumption significantly; they don't believe that fuel-efficient driving practices will not substantially increase trip times; they don't believe that fitting lower-powered engines will save fuel; and they don't believe that using lower-powered engines will not substantially increase trip times.
As I said at the outset one of my aims in writing this is to try to stimulate a discussion. Some people may think I have got it all wrong. Please say so and why. Others may think the situation in their country is completely different. Again I am very interested to hear how it is different and particularly why it is different.
Regards to you all,
John de Pont
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The ROAD-TRANSPORT-TECHNOLOGY mailing list is published by
International Forum for Road Transport Technology <http://www.road-transport-technology.org/>
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The ROAD-TRANSPORT-TECHNOLOGY mailing list is published by
International Forum for Road Transport Technology <http://www.road-transport-technology.org/>
***************************************************************
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The ROAD-TRANSPORT-TECHNOLOGY mailing list is published by
International Forum for Road Transport Technology <http://www.road-transport-technology.org/>
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The ROAD-TRANSPORT-TECHNOLOGY mailing list is published by
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www.road-transport-technology.org
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