Efficient Oil Pump Helps 2011 Chevy Cruze Eco Achieve 40 MPG on the Highway
By Scott Doggett August 25, 2010
By Scott Doggett, Contributing Editor
Fuel-economy improvements related to traditional powertrains aren't so much occurring in leaps and bounds these days as they are in baby steps.
Right, the variable displacement oil pump improves the Chevy Cruze's fuel efficiency. The pump body pivots (blue lines), causing the vanes (red lines) to move, resulting in just the right volume of oil being pumped. When less oil is pumped, less energy is needed, which saves fuel. The pump is standard on the Ecotec 1.4-liter turbocharged engine.
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Take, for instance, a story that's splashed all over the blogosphere today, more often than not re-posted verbatim from a news release issued by Chevrolet this morning.
The news release begins: "The oil pump in the engine of the 2011 Chevrolet Cruze takes a laid-back approach to its work, delivering the precise amount of oil needed during all driving conditions. That requires the engine to work less versus a conventional pump and ultimately saves fuel."
By lowering the volume of oil GM engineers reduced the amount of energy, or torque, required to pump the oil, without taking necessary lubrication away from the engine, Mike Katerberg, assistant chief engineer for the 1.4-liter engine, explained in the statement.
Reducing the torque demand reduces fuel consumption and it's a simple, durable, maintenance-free design that GM has used in its transmissions for years and more recently in its hybrid vehicles, he said.
What he didn't mention - and what doesn't appear anywhere in the news release - is the pump's contribution to the fuel economy of the model (which combined with the Ecotec 1.4-liter turbocharged engine helps the Cruze Eco that's fitted with a standard six-speed transmission achieve an expected segment-leading estimated 40 mpg on the highway).
For that information, we turned to Tom Read with GM Powertrain and Advanced Technology Communications. Read said the oil pump's contribution to the Cruze's fuel savings "is less than one percent." In other words, it's contribution is very small. And that's fine.
"The important point is that all of these incremental improvements, added together, we hope will make a really high-mileage vehicle," he said. "We're just trying to highlight some of those that you might not be aware of" with this news release and others that have come before it and will surely follow.
Read noted that many people presently driving compact cars that get 30 mpg are aware that GM and other automakers are shooting for 40 mpg and beyond in the compact-car segment, but they don't realize how the fuel-economy gains come to pass. The news releases are intended to educate the public, he said,
"The mileage improvement doesn't happen overnight," he said, but rather though many incremental gains such as the new variable-displacement oil pump appearing on the upcoming Cruze.
Moreover, he said the benefits of the oil pump increase when used with other technologies such as variable-valve timing, which operate using oil pressure. Variable-valve timing adjusts the engine valves' opening and closing timing for optimal performance, fuel efficiency and emissions across the rpm band, including greater low-rpm torque.
The all-new Cruze is scheduled to begin arriving in U.S. dealerships next month, starting at $16,995, including destination fees. Priced to compete in the compact-car segment, Chevrolet claims the Cruze offers more interior room, more miles per gallon in the Eco model, and more standard safety features than any of its competitors.
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Image how much fuel they would have saved if they realized a compact car with a 1.4 doesn't have to weigh 3000 lbs.
@first, lol
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