Beware of scams when improving fleet fuel economy

Beware of scams when improving fleet fuel economy

It’s gratifying to see regulators finally shift their focus from reducing NOx emissions to reducing global warming, because global warming can be reduced by improving efficiency. Improved fleet fuel economy can significantly reduce a fleet’s carbon footprint.

But beware. When fuel economy becomes an issue, charlatans come out of the woodwork. During commercial fuel economy testing at Automotive Research Associates, I encountered some rather ingenious charlatans. One wanted me to prove that placing lead balls into the fuel tank would increase fuel economy.

I drilled holes in the lead balls so they could be retrieved from the fuel tank and weighed before and after each fuel economy test. When the results showed no fuel economy benefit, the charlatan didn’t want to pay. He reasoned that the strings tied to the lead balls prohibited their movement around the gas tank, thereby limiting their function.
I’ve done considerable fuel economy testing during my career. To stimulate your thinking about improving your fleet’s fuel economy, I’ll try to impart some of my experience.

There are distinctly different approaches to improving fuel economy between line haul and P & D fleets. Both operations appreciate driveline efficiency and rolling resistance improvements, but P& D fuel economy is more significantly influenced by vehicle weight due to the need to regularly accelerate and decelerate (F=ma). Line haul trucks, on the other hand, respond more to aerodynamic improvements since average speeds are relatively constant, and higher speeds mean more aero drag.

Engine builders tried their best to improve fuel economy, but NOx emissions regulations forced serious compromises. Look for renewed OEM efforts on fuel economy. In the meantime, I think you might want to consider (1) making sure all your engines are properly tuned; (2) running your engines as hot as possible; (3) using lower viscosity oils; (4) eliminating idling; and (5) reducing engine speeds (RPMs).

When running mileage marathons, the best fuel economy was obtained when the engine was operated with elevated coolant temperatures (290 F).  Higher temperatures reduce intake charge density effectively decreasing the displacement of the engine. Of course, higher coolant temperatures can’t be utilized unless you can prevent coolant boil over. We used 20 PSI radiator caps and watched for signs of overflow.

Emphasis on improving fuel economy will accelerate the use of lower viscosity engine and driveline oils. Racers long ago learned that viscosity is an important engine oil property when it comes to horsepower. It’s simple physics – lighter oils require less horsepower to pump. European truckers have used 10W30 and 10W40 oils for years without problems. Run the lightest oil you can run while maintaining adequate oil pressure (25 PSI or more at hot idle). Engine builders will soon learn to tighten up crankshaft bearing and connecting rod side play clearances so you can run even lighter oils.

Claims that lower viscosity engine oils can improve fuel economy 4-5% are overstated. Examine those claims carefully. Most of them require a reduction in vehicle speed since vehicle speed reduction has a more pronounced affect on fuel economy than oil viscosity. Single viscosity grade reductions might be expected to yield gains of 1-2%, but that can still save your fleet a lot of money.

Engines are basically air pumps. The slower you can rotate the engine, the more efficient it becomes. Use the highest gear possible.

Tire inflation pressures significantly affect rolling resistance. Run the highest pressures possible without adversely affecting tire wear. Also carefully align all vehicle wheels. Any side scrub reduces fuel economy. We spent hours aligning the wheels on our mileage marathon cars.

Also consider lighter viscosity transmission, differential, and wheel end lubricants. As long as the parts don’t come in contact with each other, fuel economy can be improved using lighter oils.

You May Also Like

Allison to supply e-axle to McNeilus Volterra ZSL electric refuse vehicle

Allison will provide e-Axles to Oshkosh for North America’s first fully integrated, zero-emission electric refuse collection vehicle.

McNeilus-Volterra-ZSL-refuse-EV

Allison Transmission announced that it was selected by Oshkosh Corp. as its electric axle supplier for a new fully integrated, zero-emission electric refuse collection vehicle. The Allison eGen Power 100S has been successfully integrated into the McNeilus Volterra ZSL electric refuse vehicle, the company said.

Oshkosh said it recognized the eGen Power 100S architecture efficiency advantage in heavy stop-start refuse applications would extend the eRCV’s range. Each vehicle will be built using two eGen Power 100S e-Axles in tandem configuration, while delivering cleaner air and quieter operation in communities where deployed. A differential lock will be utilized for optimized traction.

Rypos DPFs pass CARB compliance test

The CARB certification shows Rypos’ active diesel particulate filters go beyond normal EPA emissions standards.

Rypos-active-diesel-particulate-filter-ADPF-CARB-certification
Webb launches UltraGrip brake pads in three formulations

Webb says the Plus, Premium and Severe-Duty options were made to suit differing applications.

Webb-UltraGrip-Brake-Pad
Share your tire health management practices and you could win

Calling all managers, owner operators and presidents, Class 1 through Class 8 — take this anonymous survey for a chance to win.

tire-health-management-practices-survey
BorgWarner announces JV with Chinese HD parts supplier

BorgWarner plans to team up with Shaanxi Fast Auto Drive Group, a Chinese supplier known for transmission and drivetrain systems.

BorgWarner-logo-new

Other Posts

US Tarp bolsters leadership with promotions

Company growth, product development, and building client bonds will stay top of mind in the new roles.

US-Tarp-Jason-Frazier-Marti-Kupres
ZF expands [pro]Academy training

The company is adding another 40 training modules to the 160 they already offer.

ZF-HDAW-2024-1400
Do biodiesel and bitter cold mix?

Three cities partnered with Optimus Technologies to keep their fleets going at an 89% runtime on B100, in temperatures as low as -17°F.

REG-June-blog-image-biodiesel
Cummins-Meritor provides an aftermarket strategy update

The company’s integration progress, technology advancements, eCommerce growth, and future strategies in heavy-duty trucking.

cummins-meritor-aftermarket-strategy-hdaw-1400