INDIANAPOLIS, Ind. – When working with a client, Ralph Haire, president of Thomasville, N.C.-based Synergy Design and Production, was issued a challenge: to build a work truck that does the job just as well as the vehicle it replaces, but weighs 2,300 lbs less. The reason was obvious.

Haire had read an Environmental Protection Agency (EPA) report that indicated every 100 lbs of weight reduction translates to a 1-2% improvement in fuel economy. That, combined with the added benefit that trimming a 12,300-lb GVW truck to under 10,001 lbs would get it out from under the watch of the DoT, was enough to send Haire on a weight-loss mission. The result was a lightweight delivery truck Synergy has since dubbed the SynergyLite Green truck.

The fleet was initially comprised of 184 trucks, each with a gross vehicle weight of 12,300 lbs, a 14-ft. body and a heavy liftgate.

“Everything that was steel had to go and everything that was wood had to go, replaced with composite panels or aluminum components,” Haire recalled during a seminar on Using Vehicle Weight Reduction to Improve Fuel Efficiency, presented at the Green Truck Summit.

Haire substituted the 14-ft. body with a 12-footer that was two inches wider, allowing it to carry the same amount of cargo while saving substantial weight. He then replaced the heavy steel liftgate with a lightweight aluminum scissor-lift. That alone represented a weight reduction of 1,301 lbs (from 1,760 lbs to just 459).

“We started to immediately pick up fuel economy,” Haire recalled. Better yet, the liftgate was able to double as the rear door, eliminating the need for a roll-up door – another 300-lb savings.

Haire said the general rule of thumb when switching to aluminum components is, they tend to weigh half as much, and cost twice as much as their steel counterparts. Still, when measuring the life-cycle costs of the new vehicles, Haire found the additional cost of aluminum was recovered thanks to its lighter weight.

When all was said and done, Haire said the new trucks weighed about 25% less than the vehicles they replaced. The benefits of getting the trucks below the DoT threshold also meant a reduction in administrative costs, not to mention the benefits of bypassing weigh scales and eliminating the need for log books and driver physicals.

In measuring the value of the weight-shaving initiative, Haire pointed out every new truck in the fleet of 184 vehicles would require 240 fewer fill-ups over the course of its life, for a fleet-wide total of 44,160 fewer fill-ups. Attributing a $50 billable hour to every fill-up for unproductive time spent adding fuel, Haire figures the transition saved the fleet in the neighbourhood of $2.2 million.

“And that’s fuel that doesn’t have to leave Saudi Arabia,” he added.

Also on-hand to share a weight-loss success story was George Mayhew, vehicle design and specifications specialist with Verizon Communications. Verizon set out to reduce the weight of its light aerial lift trucks, which carried a 29-ft. single person aerial lift. In an effort to reduce weight, Mayhew said Verizon: downsized from an 8.1-litre engine to a 5.4-litre option; reduced towing capacity from 9,000 lbs to 3,000; switched to aluminum ladder racks and other components; switched to a lighter tow hitch; and eliminated some optional equipment such as an air compressor, second nitrogen tank holder, etc.

“In a lot of cases, those options were never used,” Mayhew said. Moving to a smaller engine and chassis resulted in an overall cost savings of about $8,000 per vehicle, even after many steel components were replaced with pricier aluminum alternatives.

In total, the empty weight of the chassis was reduced 1,790 lbs and the GVWR was downsized from 17,500 lbs to 13,000 lbs.
Payload was reduced 2,278 lbs, but Mayhew said it was still sufficient for the application. The body layout and compartment features all remained the same and the aerial tower was repositioned by just a few inches.

Mayhew admitted the 5.4-litre engine was not powerful enough in mountainous regions, but it worked fine in most areas.
Mayhew acknowledged there are risks in spec’ing lightweight trucks, including the possibility maintenance costs could rise when running a chassis that’s constantly loaded to near its capacity.

“Anytime you have a chassis loaded to near capacity, you’re going to see more ball joint failures and brakes are going to cost you more. It was a concern. You don’t want to load the truck right up to its GVWR, so there’s a certain amount of monitoring of payload that has to be done,” he warned. Mayhew said he noticed some premature wearing of ball joints on the downsized trucks, but over time there were very few maintenance issues.

“Generally, from the records I’ve seen, we have not seen a big spike in maintenance on the lighter trucks,” he said.

Mayhew pointed out that any savings resulting from lightweight spec’ing will be lost if driver training isn’t involved.

“There will be minimal fuel savings if engine idling is not minimized,” Mayhew pointed out. “If they’re going to sit there and idle the truck all day, the only savings is going to be how much fuel the 5.4-litre is going to consume while idling compared to how much an 8.1-litre is going to consume while idling. If you can’t get on top of engine idling, you’re not going to save that much just by doing weight reduction.”

Mayhew had a few recommendations for work truck fleets that are looking to spec’ lighter weight trucks. For starters, he suggested involving all suppliers in the process and ensuring they provide accurate component weights.

“Some vendors ballpark things a lot,” he warned. “That’s fine to an extent but when you’re ballparking a lot of individual items and they are all plus or minus 50 lbs, that can make a big difference. It can make a difference on whether this thing is a go or no-go.”

Mayhew said a fleet would be well advised to build a complete prototype and then weigh it.

“No matter how well those weights are calculated, the final end product, once it goes across the scales, is going to be different than any calculations anyone has done,” he said.

Mayhew also reminded fleet managers to consider the weight of fuel and occupants and to ask the OE if they included fuel in their weight estimates.

“A few hundred pounds can make all the difference in the world,” Mayhew noted. Finally, he advised fleets to be up front with drivers on why their trucks are being spec’d differently.

“We eliminated some options and we had to let the users know we were doing this to reduce costs, but also make sure they could live with those changes we made,” he said.