Volvo Trucks North America announced Wednesday, Sept. 20, that beginning in the second quarter of 2007 its customers will be able to equip their trucks with the Volvo I-Shift transmission – an automated mechanical transmission that offers two-pedal operation. Initially, the 12-speed I-Shift will be available only on Volvo trucks spec’d with Volvo’s new engines for 2007 – the D11, D13 and D16. The transmission will be available on all truck models – the VN and VT highway tractors and the VHD vocational truck.
“We believe customers will immediately recognize the advantages I-Shift offers for productivity, lower cost of operation, driver recruitment and retention, and safety,” said Scott Kress, senior vice president of sales and marketing. “The combination of I-Shift with Volvo’s new engine family gives our customers a complete vehicle and drivetrain solution. Customers can always get the perfect ratio at the right time for optimal engine and vehicle performance, which means a higher degree of productivity, fuel economy and reliability.”
Volvo will offer three I-Shift models, with the ability to handle all power and torque inputs from its new engine family, including the top 600 hp/2050 lb-ft rating. Although the I-Shift is new to North America, Volvo has sold about 80,000 in other markets since it was introduced in early 2002. In addition, Volvo has been building automated manual transmissions for other markets since 1987.
One of Volvo’s major goals with the introduction of I-Shift is improving fuel economy. Due to the integration of the transmission and Volvo engines, the I-Shift is programmed with its engine’s efficiency map for each engine rating. Using this information and various sensors, the transmission calculates vehicle speed, acceleration, torque demand, weight, rolling and air resistance, and road grade to continuously predict and select the most efficient utilization of the engine for the next 30 seconds, Volvo says.
The road grade sensor – which Volvo claims as an exclusive feature – helps determine which gear to start off in and when the transmission can skip-shift for better fuel economy.
Another exclusive feature related to fuel economy is Eco-Roll, which is intended to improve fuel economy in the top gear when operating in rolling hills. Eco-Roll automatically disengages the engine when the vehicle is in top gear on a long, slight downgrade. By allowing the engine to idle in these situations, Eco-Roll can reduce parasitic losses by as much as 30 hp, Volvo says.
A fuel economy-related option is direct drive, which ties the output shaft directly into the input shaft when the I-Shift is operating in 12th gear. The result is less power loss due to friction, saving as much as 1.5 percent in fuel versus overdrive transmissions.
If the customer wants, the I-Shift can be spec’d with the ability to shift from fuel economy mode to performance mode and to improve acceleration by using a “kick-down switch” connected to the accelerator pedal. An Idle Governor driving mode allows drivers to creep in slow traffic without using the accelerator pedal.
The I-Shift will be available with a 5-year/750,000-mile parts and labor warranty for engines with 1,750 lb.-ft. of torque or less, and a 3-year/500,000-mile warranty for engines above 1750 lb-ft of torque.
