Volvo will soon start delivering the I-Shift automated mechanical transmission in next year’s trucks here in North America. As other OEs will do, Volvo trucks with 2007 engines will be designated 2008 models. The I-Shift can be ordered now for deliver in the second quarter of 2007.

It’s not a new transmission, in fact. Volvo says it’s sold some 80,000 I-Shifts in other markets since the introduction in early 2002. It’s actually the Swedish company’s third generation of automated manual gearboxes, the first going back to 1987. Europeans bought 19,000 I-Shifts in the first six months of 2006.

There will be three I-Shift models here, with the ability to handle all power and torque inputs from the new Volvo engine family, including the 600-horse/2050-lb-ft rating. They’ll be available for all Volvo truck models, including the Volvo VN and VT highway tractors, and the VHD vocational truck. All are 12-speeds, one of them a direct-drive model, the other two with a 0.78 overdrive. The two that are matched to D11 and D13 engines weigh 597 lb (275 kg), while the heavy-duty model for the big D16 weighs in at 610 lb (281 kg), all pretty light.

The I-Shift is a single-countershaft transmission with a splitter, a main section with three forward and one reverse gears, plus a range gear. There are no synchronizers in its main section. With a clutch but no clutch pedal, the transmission’s controls are located on a console and lever attached to the driver’s seat. The company makes the point that the I-Shift’s electronic control unit (ECU), the VECTRO engine management system, and the Volvo vehicle ECU were designed by the same team and use the same protocols.

An I-Shift is programmed with the efficiency map for each engine rating. It combines that information with sensors to continuously calculate the truck’s speed, acceleration, torque demand, weight, rolling and air resistance, and road grade in order to predict and select the engine’s most efficient operational parameters for the next 30 seconds. Volvo says the result is optimum performance and fuel economy.

That grade sensor, exclusive to Volvo, helps the transmission decide on the start-off gear and when it can skip-shift. It also senses how the gradient is changing, which helps predict whether a gear change will be necessary. Fully integrated into the Volvo engine brake system, the system can automatically downshift to maintain set cruise speeds on downhills.

Then there’s ‘Eco-Roll’, an energy management feature that aims to improve fuel economy when operating in rolling hills. It automatically disengages the engine when the truck’s in top gear on a long, slight downgrade which demands no engine torque. By allowing the engine to idle, the feature is claimed to reduce parasitic losses by as much as 30 hp. The engine is re-engaged when road speed hits the cruise-control setpoint, when the driver touches the brake, accelerator, or the engine-brake control stalk.

Among other features and options, the I-Shift has two major operating modes: Fuel Economy (E) and Performance (P). In ‘E’ mode, the transmission will select shift points and engine parameters to maximize fuel economy. In ‘P’ mode, gradeability is maximized.

There’s also a third and very useful option for times when traffic is jammed and you’re just creeping along. The ‘Idle Governor’ driving mode complements the cruise control when driving slowly, without cycling the clutch. It leaves the engine operating at idle and adjusts road speed by selecting the gear that best suits the traffic. It adjusts torque to maintain idle speed and thereby constant vehicle speed, although the engine load may vary. A slight drag on the brake will cause the transmission to change down one gear, while a touch of the throttle increases to the next higher gear. The clutch is only disengaged when the truck is stopped.

The I-Shift warranty is five years/750,000 miles parts and labor for engines with 1750 lb ft of torque or less, and three years/500,000 miles for engines above 1750 lb ft.