MONTREAL, Que. – They use a lot less fuel in city driving, they produce less greenhouse gas emissions and they accelerate nicely. As for giving buyers an acceptably quick return on investment though, even with generous subsidies currently on offer by Transports Quebec, hybrid diesel-electric delivery trucks cannot make the grade.

This is the conclusion of FPInovations in Montreal, which released the results of two long-term studies on the trucks this year. FPInnovations collected and compared fuel consumption data from hybrid trucks and conventional diesel trucks and compared the capital costs of each.

The best-case scenario, assuming 50,000 kilometres of city driving a year, suggested profitability after four years. A more realistic scenario, logging about 17,600 kms a year, drives the hybrid truck into profitability only after 12 years.

On the bright side, larger subsidies would encourage the broader adoption of hybrid trucks and presumably drive down their cost as economies of scales improved. Their cost-effectiveness would also improve with higher diesel costs and with carbon credits.

The 58-page report on the first study is titled Evaluation des performances et de la rentabilite  economique d’un camion hybrid-diesel electrique de classe 7 pour livraison (translated to Evaluation of the performance and economic profitability of a hybrid diesel-electric Class 7 truck for deliveries). FPInnovations compared a 2009 Class 7 T370 Kenworth diesel-electric hybrid with two FC 80 Freightliners, one a 2001 and the other a 2002.

The Societe des alcools du Quebec (Quebec Alcohol Corporation) operated the trucks and Transports Quebec provided funding for the study, which ran from May 2009 to the end of September 2010. After the analysis of this trial was completed, another three-month trial was carried out.

In short, as the study design and execution is very detailed, the researchers collected fuel consumption and other data from city (speeds less than 40 km/h); road (speeds between 40 and 70 km/h); and highway (speeds over 70 km/h) driving.

In city driving the hybrid burned 33 litres/100 km, compared to 36.8 and 41.9 L/100 km for the two conventional trucks. Fuel consumption on the road was 25.4 L/100 km for the hybrid and 22 and 26.4 L/100 km for the conventional trucks. On the highway, the hybrid got 22.1 L/100 km and the conventional trucks burned 22 and 24.5 L/100 km.

The researchers also did a start-stop cycle evaluation on the Transport Canada test track in Blainville, Que., and a simulation.
Although the fuel consumption results were good for the city driving, they did not compensate for the net additional cost of the hybrid over a conventional truck. The purchase price premium for a hybrid was $35,000 in 2010 (but $40,000 when the study began). FPInnovations subtracted $10,500 to reflect a subsidy available from Transports Quebec’s Programme d’aide gouvernementale a l’amelioration de l’efficacite energetique dans le transport routier, ferroviaire et maritime (Program for Improving Energy Efficiency in Road, Rail and Marine Transportation).

It subtracted an additional $2,000 for reduced brake maintenance, thanks to the hybrid’s regenerative braking system. It then added $10,000 for the anticipated need to purchase new storage batteries after 10 years of operation. The net cost over a conventional truck came to $32,500.

So even with fuel savings of between 11.8% and 21.2% for city driving, the math spoke against the hybrid truck.

The 101-page report on the second study is titled Evaluation des performances et des practique de conduite d’un camion hybride diesel-electrique de classe 7 pour livraison (in English: Evaluation of performance and driving practices of a hybrid diesel-electric Class 7 truck for deliveries). FPInnovations collected fuel consumption and other data from a 2009 Class 7 T370 Kenworth diesel-electric hybrid with a reefer and several conventional truck models, both in the field and on the track.  

Agropur distributors drove the trucks and Transports Quebec provided funding for the study, which ran from November 2009 until December 2010.

The study was designed to evaluate the hybrid technology’s performance in field operations and measure its fuel consumption relative to conventional trucks.

It was also designed to reveal driving practices that would maximize the potential benefits of the hybrid.

As with the first study, FPInnovations concluded that the return on investment for the hybrid was insufficient to justify its purchase.

Data collected on a variety of driver-influenced variables, such as frequency of braking and aggressiveness of acceleration revealed maladaptive driving habits carried over from conventional trucks.

The data also suggested some best practices, such as adapting the hybrid’s speed to the traffic conditions, reducing speed and avoiding abrupt braking and acceleration.

The reports on these two studies are valuable reading for any fleet manager considering hybrid trucks.

The detail is exceptional and FPInnovations presents thoughtful conclusions on many aspects of these vehicles’ performance. They are available in French from FPInnovations.