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Cummins/Peterbilt SuperTruck shows 54% improvement in fuel economy, 61% improvement in freight efficiency

The new SuperTruck achieved a 54% increase in fuel economy. Click to enlarge.

Cummins Inc. and Peterbilt Motors Company, a division of PACCAR, released test results showing their demonstration SuperTruck tractor-trailer achieved a 54% increase in fuel economy, averaging nearly 10 mpg US (23.5 l/100 km) under real world driving conditions. In addition, the truck also demonstrated a 61% improvement in freight efficiency during testing compared to a baseline truck driving the same route. Freight efficiency is based on payload weight and fuel efficiency expressed in ton-miles per gallon.

Cummins is a prime contractor leading one of four vertical teams under the Department of Energy’s SuperTruck project, one of several initiatives under the 21st Century Truck Partnership. (Earlier post.) Objectives for the program, which runs from April 2010 through April 2014, include:

  • Demonstrate 50% thermal efficiency improvements in test cell;
  • Demonstrate a 50% drive-cycle freight efficiency improvement;
  • Demonstrate 68% freight efficiency improvement on 24hr cycle; and
  • Scope and demonstrate improvements for a 55% engine efficiency.

Results. The results reported reflect the second major demonstration milestone in the SuperTruck project—the attainment of 50% drive-cycle freight efficiency. Still to come are the 24-hour Cycle Freight Efficiency Demonstration (December 2013) and the 55% BTE scoping and demonstration (Aril 2014).

During the reported test, the Class 8 Peterbilt 587 powered by a Cummins ISX15 engine averaged 9.9 mpg (23.8 l/100 km) during testing last fall on US Route 287 between Fort Worth and Vernon, Texas. The testing was conducted over 11 runs meeting SAE International test standards along a 312-mile route. The tractor-trailer had a combined gross weight of 65,000 lbs.

Today’s long-haul trucks typically achieve between 5.5 and 6.5 mpg (42.8 and 36.2 l/100 km). The 54% increase in fuel economy would save about $25,000 annually based on today’s diesel fuel prices for a long-haul truck traveling 120,000 miles per year. It would also translate into a 35% reduction in annual greenhouse gases per truck.

The reported 61% freight efficiency significantly exceeded the program goal of 50% for this demonstration.

Approach to technology improvements. Source: Cummins. Click to enlarge.

The SuperTruck. The SuperTruck developed by the two companies and their partners features a higher-efficiency engine and an aerodynamic tractor-trailer that significantly reduces drag. The truck also includes a Rankine cycle waste heat recovery system; electronic controls that use route information to optimize fuel use; tires with lower rolling resistance; and lighter-weight material throughout.

Cummins personnel and their partners in other companies and research institutions have been focused on the engine and its integration with the powertrain. To raise the thermal efficiency of the engine, they worked with increasing the compression ratio, and optimizing piston bowl shape, injectors and calibration.

Sources of increased engine thermal efficiency. Source: Cummins. Click to enlarge.

Gas flow improvements included a lower delta-P EGR loop and turbocharger match. Parasitic power reductions addressed cylinder kit friction and cooling pump power.

In addition to the truck’s exterior, Peterbilt and its partners have been working on improvements in the drivetrain, the idle management system, weight reduction and vehicle climate control. Eaton’s advanced transmission facilitates further engine downspeeding for additional fuel economy benefits.

Cummins, Peterbilt and their program partners will have invested $38.8 million in private funds over the four-year life of their SuperTruck program, with critical support coming through awarded matching grants from the Department of Energy’s Vehicle Technologies Program.

Testing will continue in 2013 on a new Peterbilt 579 that Cummins and Peterbilt are confident will take what has been achieved so far to even higher levels. The testing will address use of the tractor-trailer over a 24-hour period; including periods when drivers are at rest but still need power for such things as air conditioning and small appliances.




Up to 61% gain in efficiency may be a lot more than many expected to be possible and probably more could be done.

Yearly fuel savings of $25,000/year/truck could become $50,000 when fuel price goes up from $3.50/gal to $7.00+/gal.

Almost to good to be true.

Politicians with the country's health as their goal would mandate the progressive use of those trucks, regardless of the objections from the Oil Barons and their highly paid lobbies.

However, as long as the RP controls the House, nothing will be passed to reduce liquid fuel consumption and emissions. The same inaction will take place in Canada for the very same reason.




is this adaptable for CNG or LNG?



Yes, both LNG and CNG. Cummins has a joint venture with Westport Innovations for CNG and LNG diesels. http://www.westport.com/


You do not need to pass new laws. All you have to do is show that you will save money. I see more and more of the basic aerodynamic skirts.



In Canada, fuel taxes and vehicles registration fees can be reduced and/or raised without new laws but it is not always so in USA.

To persuade operators to spent $100K more to buy their rigs, a fuel economy of $50k/year/vehicle and higher registration fees would be more convincing than $25k/year/vehicle and low registration fees?


The major principles for this, specifically better powerplants, better aerodynamics and lighter weight (greater cargo fraction), have been obvious for a long time.  Now it's time to see them hit the roads.

Maybe with the overhead catenary electric feed, we can get rid of combustion-powered trucks altogether.


why? a 50% ICE(which this truck has) is way more efficient than 90% of the electric powerplants out there.

We got to start greening the grid first.


A 60% CCGT burning natural gas uses less of a cheaper fuel than a 50% truck burning ULSD.


maybe in 20 yrs will there be enough of those to make a dent in the total US grid. That would be like me saying oh yea we will just put 55% NG/D RCCI engines in every truck


If we really wanted to make a difference we'd just make our electrical grid 78% nuclear.  France did it in 15 years.

Even if you don't, a simple-cycle gas turbine from GE operating at 46% efficiency is going to cost less for fuel and emit less CO2 than a 50%-efficient diesel burning ULSD.  The gas turbine would have the additional benefits of moving its emissions (however small) and noise outside of urban areas.


The politicians should mandate these features.

Otherwise this project will end up like the PNGV or the EV1 or the Insight I.

These things are almost certainly financially unsound but are MORE certainly desired by politicians and others untrained and uninterested in engineering and business economics.

So they must be mandated - there are already to many nice sounding things we cannot have.

Clearly this is worth it at any price.

If you are a greedy truck or trucking company shareholder - tough, this is the price you have to pay so the rest of us can see these spiffy, Hi-Tech trucks rolling by.

If you think this will increase your food budget - get on welfare where your supposed to be.


Weird - if efficiency was your goal, why not hybridize?


Because hybridization doesn't make sense when braking events are a small part of the total drag losses and sustained operation at speed is the rule.


This is great! The other part of the story of course should be reducing/eliminating the incentives pushing truckers to go beyond posted speed limits!


Judging by the aerodynamic devices that are already present on interstate trucks, these changes will be widely implemented. There's no need for government intervention when Walmart keeps pushing fleets to tighter margins.

What I find interesting is that most of the efficiency gains are not from aero.

I know that fixed-site turbines can achieve great efficiency, but assume that these are mostly from bulky and heavy heat-recovery systems. Can these systems be scaled-down to a point where it makes sense to haul them around the country at 65mph?
If they can't be scaled-down, then it makes sense to concentrate on diesel-cycle powerplants (whether they burn diesel or NG).

Can these systems be scaled-down to a point where it makes sense to haul them around the country at 65mph?
If they can't be scaled-down, then it makes sense to concentrate on diesel-cycle powerplants
Only if the powerplant and the vehicle can't be separated and linked by e.g. overhead wires (see recent GCC post on that).  Removing the engine from the vehicle removes its weight and also the weight of the fuel supply, allowing it to be replaced with cargo.  It's a win on many levels.

Also; http://www.gizmag.com/go/3077/

Nick Lyons

I will be interested to see what the incremental cost of these engines is, considering the addition of both turbo compounding and Rankine cycle waste heat recovery.


Way to go. Efficient diesel and efficient aerodynamics. Imagine cutting total trucking fuel consumption by 50%. This is an enormous change, and we should do it right now. No need to wait.

We also should require ALL trucks and buses to have mileage/MPG instrumentation and displays so drivers can SEE consumption and adopt fuel/energy-saving behavior. I see it locally in the that hybrid/diesel bus drivers seem to drive much more sensibly than the the drivers of the old buses -- and I think part of the reason is that they see in real time what mpg they are getting.


@RFH, completely true that electrification is detrimental to CO2/mile until the average grid mix is much cleaner (CO2/kWh) than it is now.

>why? a 50% ICE(which this truck has) is way more efficient than 90% >of the electric powerplants out there.

>We got to start greening the grid first.

Yes, indeed. But in the meantime, reduce fuel consumption by 39% by using the described technology. Why 39%, you ask? Well, they did use the trick of saying "61% improvement in (mileage)". However, the reduction in fuel use not quite as high as 61%:

6.0 mpg is 1/6 gpm is 1/6*1.609km/3.8L = 39.33 L/100km
(6.0 is the midpoint of the 5.5-6.5 range cited, for lack of exact data)
9.9 mpg is 1/9.9 gpm is 1/9.9*1.609km/3.8L = 23.84 L/100km

23.84/39.33 = 0.606, or a reduction of 1-0.60=0.394 or 39.4%

39.4% is not 61%, but it is still a truly awesome number.

You can also get the number as (X/9.9)/(X/6)=6/9.9=0.394=39.4%.

Well, they did use the trick of saying "61% improvement in (mileage)". However, the reduction in fuel use not quite as high as 61%
The improvement is in freight ton-miles per gallon.  Vehicle (tare) weight went down, gross stayed the same, freight went up.

@ HarveyD

The power to tax is the power to destroy. Raising taxes without having to pass new laws as they do in Canada goes one step closer.

Incidentally when visting Canada on several occasions I noticed that there is no variation in the price of gasoline. Every gas station posts the identical price per liter. Do Canadian gas stations engage in price fixing? If so is that legal?


I wonder what the extra price is for the rankine cycle. This has always seemed very interesting to me and in the past there have been many attempts at a rankine bottoming cycle. Maybe now technology and fuel prices have now reached the point that the cost and complexity premium is acceptable and paid back within X years?

Jim McLaughlin

While 5.5 to 6.5 mpg might be typical for the average truck on US highways, those built after 2010 are considerably better. I hear of 7 to 8 mpg regularly. The Selective Catalytic Reduction (SCR) exhaust after treatment added by most (and eventually all) engine manufacturers for US10 EPA regulation compliance allows hotter engine operation and often eliminates the need to actively regenerate the diesel particulate filter. All of which improves efficiency.

Scania has offered turbo compounding for some time and Mercedes is adding it soon, so presumably it will come to the very similar Detroit Diesel engines shortly (used by Frieghtliner). With the 2016 Greenhouse Gas Regulations on the way, all engine manufacturers might have turbo compound offerings. This may be the end of traditional manual transmissions, since a clumsy shift can break things with the extreme gear down ratios of turbo compounding.


Mannstein...yes, Big Oil has been fixing retail gasoline & diesel fuel prices for decades in Canada. They have finally been found guilty by a lower court last month but they will take it up to the Supreme Court during the next 12 to 24 months.

With the current Fed government, Big Oil has a 90% chance of winning their case in the Supreme Court and they will continue to fix and vary retail prices as they wish.

PS: In our region, retail price goes up from $1.33/l (about $5/gal) to $1.47/l ($5.52/gal) every Thursday (pm) for 3 days. All stations change their price at the very same time. That is done every week without price fixing?

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