A: “I’ve never had anyone ask about 80 mph fuel economy before,” GM hybrid spokesman Brian Corbett said. “But cruising at that speed is not efficient with any type of car or truck or any size engine. Typically, an engine is most efficient when it is cruising at 55 to 60 mph.”
Toyota spokesman Bill Kwong added that since the government doesn’t test vehicles at 80 mph, Toyota doesn’t either.
The battery pack is designed to get the vehicle started and moving, which is why mileage is best in stop-and-go driving, and to give a boost to pass or climb so the gas engine doesn’t have to work as hard. But a battery pack isn’t working at 80 mph on the interstate.
Q: We’ve been told for years that avoiding “jack-rabbit starts” from a light and turning off the engine when waiting for a train to pass will save fuel.
Does this hold true for the hybrids or electrics?
A: Hybrids shut off the gas engine rather than let it idle at a stoplight or when waiting for a train to pass. If you avoid a jack-rabbit start and use a light foot, you can get going again in battery.
Plug-ins, such as the Chevy Volt, don’t use the gas engine until the batteries need to be recharged.
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