Inside Volvo

The new Volvo FH with I-Save: long-haul fuel efficiency at its best

2019-05-14 | 6 min read | 6 min read

Text: Lina Törnquist Photo: Arne Edström Illustration: Daniel Tegeland

The new Volvo FH with I-Save can cut fuel costs by up to seven per cent. Its secret? Rigorous testing, a unique D13TC engine and a number of updated fuel-saving features that combine to make it Volvo Trucks' most fuel-efficient truck to date.

Volvo FH with I-Save combines the Volvo Turbo Compound D13TC engine with several high-tech features including updated I-See and I-Cruise.

On a highway in Sweden, a truck is heading westward to a secret test track. Behind the wheel is Lars Sjöö, Chief Project Manager at Volvo Trucks. Together with a team of dedicated engineers, he is in the final stages of testing the new Volvo FH with I-Save. Every feature of this vehicle, from its new low-friction rear axles to the interior shape of the pistons, has been designed to save fuel.

“After decades and decades of working on fuel efficiency at Volvo Trucks, there is no magic screw you can adjust to save up to seven per cent in fuel costs. Instead, it’s a question of chasing every fraction of a per cent through innovation and fine-tuning,” says Lars Sjöö.

Key to the low fuel use is the D13TC engine, with Turbo Compound technology that is used in high-power aircraft engines and has been adapted for the road. Put simply, the Turbo Compound unit is an additional turbine positioned after the turbo in the exhaust flow that reuses excess heat and energy from the exhaust gases. By making use of excess energy, the TC unit delivers much more torque to the crankshaft – producing a powerful and extremely fuel-efficient engine.

And it is not only the Turbo Compound unit that delivers fuel savings in the Volvo FH with I-Save. The whole driveline has been calibrated for maximum efficiency. For example, the truck engine pistons have been given a new wave-shaped interior. The design makes use of gas and fluid mechanics to guide the heat to the centre of the cylinder and away from the engine walls, where energy would otherwise be lost as heat. “The wave-shaped pistons are a new Volvo Trucks’ patented innovation. By changing the shape of the piston, we guide the flames back to the centre of the cylinder. This results in more efficent combustion, where less energy is lost as heat,” says Mats Franzén, Powertrain Strategy Director at Volvo Trucks.

I-Save also integrates Volvo Trucks’ state-of-the-art technologies such as map-based I-See software and I-Cruise with I-Roll, Engine Idle shutdown and Power Steering Pump with Variable Displacement. The result is a truck that saves up to seven per cent in fuel costs. “For our largest customer group – long haul – fuel is the largest cost. So it is important that we develop new efficient solutions,” says Mats Franzén.

There are also two other major benefits. For one, the Turbo Compound engine features a cooled Exhaust Gas Recirculation System which reduces the amount of nitrogen oxide during the combustion process. This in turn cuts the need for AdBlue, lowering costs for owners still further. “The engine and the driveline are at their most effective at 1,000 revs. That’s also when the engine saves most diesel and AdBlue,” says Mats Franzén.

The other major benefit is drivability. The project team set out with a strong ambition to create a vehicle that not only saves money for owners but is also really great to drive. They have been helped along by a clever bit of engineering. By making use of waste heat and excess energy, the Turbo Compound unit delivers much more power to the crankshaft – creating higher torque at lower engine speeds. The resulting truck is powerful up hills, while the driver environment is quieter because the truck runs on low engine revs and high torque.

“For our largest customer group – long haul – fuel is the largest cost. So it is important that we develop new efficient solutions.”

The difference it makes can be felt right away. During the test period, Lars Sjöö and his colleagues have driven the truck with between 40-tonne and 60-tonne loads. They have made certain that the truck takes the hills with extra gusto and runs very quietly with any load.

In fact, every single feature of the I-Save truck has been developed through rigorous testing out on the road and different I-Save truck combinations have been compared with traditional diesel trucks. This is to get a true sense of the difference the new technology makes.

The amount of testing hours on the road are extensive. After Volvo Trucks’ professional test drivers have driven the trucks on a track during the day, the engineering team is often out driving them by nightfall. “We don’t want to be stuck in an office with some PowerPoint,” says Lars Sjöö with a smile. “When we are discussing an adjustment, we take the trucks out for a test drive to see for ourselves how things work.”

“Getting to where we are today has necessitated thousands of hours of testing, both in the lab and on the road. But now we have a vehicle that will be as good for the drivers as it is for the owners”.

In a few weeks, Lars Sjöö is all set to drive one of the new trucks back from the Volvo Trucks’ winter test track, located close to the Arctic Circle, to Volvo Trucks’ headquarters 1,700 km away. This is exactly the type of demanding, long-distance drive the truck was built for. “It’s only by spending time behind the wheel that you know you are able to deliver a solution where every feature is just as it should be,” says Lars Sjöö.

“If you only focus on fuel consumption, there’s a real risk that you will jeopardise other areas, such as driver comfort or engine performance. This way of working makes the whole process complex. But we just can’t compromise on the making of the world’s best trucks,” he says and adds: “Getting to where we are today has necessitated thousands of hours of testing, both in the lab and on the road. But now we have a vehicle that will be as good for the drivers as it is for the owners”.

We are comparing the D13TC Euro 6 step D with the Long Haul Fuel Package (I-Save) vs. D13 eSCR Euro 6 step D without the Long Haul Fuel Package. Actual fuel economy will vary depending on many factors, such as use of cruise control, actual topography, the driver’s driving experience and weather conditions. Read more here.

VOLVO FH WITH I-SAVE

Every feature of I-Save has been designed to save fuel. It is available with the Volvo FH, with either a 460 or 500 hp D13TC engine.

Engine
D13TC (Turbo Compound) 460 or 500 hp engine.

Engine idle shutdown
Saves fuel by automatically turning off the engine after 2.5 minutes of idling.

Transmission
I-Shift, I-Shift with Crawler Gears or I-Shift Dual Clutch – all with long haul optimised software.

Updated I-See
By using cloud-based map data, the updated I-See can reliably sync the truck with information from high-resolution maps in order to support the driver to save fuel. In remote locations, it uses local road data.

I-Cruise with I-Roll
Volvo Trucks Smart Cruise Control is combined with the I-Roll freewheel function that saves fuel.

Rear axles
New, less friction, highly fuel-efficient.

Power steering
Pump with variable displacement.

Volvo FH with I-Save is especially suitable for people that typically drive more than 120,000 km a year.

Are you interested in a Volvo FH with I-Save? Contact your local Volvo dealer.