Weight is only relevant to acceleration (which is partially recovered), hills (partially recovered), and rolling resistance which is only ~5% of energy usage. Even with a consistent load on the highway the batteries can help by removing parasitic loads on the engine like alternators, a/c compressors, and power steering pumps. Depending on torque demand and specifics of the engine/transmission, thrashing the battery could also be more efficient than ICE alone.
I'm sure there's stuff I've missed, but I think those are the main reasons why a number of hybrids have highway EPA ratings 10-15 mpg higher than the highest MPG ICE car ever produced.
you're totally right, I mixed up my facts. they are 10-15 mpg higher than the highest MPG ice car currently produced for the US market which is the Mitsubishi mirage.
Weight is only relevant to acceleration (which is partially recovered), hills (partially recovered), and rolling resistance which is only ~5% of energy usage. Even with a consistent load on the highway the batteries can help by removing parasitic loads on the engine like alternators, a/c compressors, and power steering pumps. Depending on torque demand and specifics of the engine/transmission, thrashing the battery could also be more efficient than ICE alone.
I'm sure there's stuff I've missed, but I think those are the main reasons why a number of hybrids have highway EPA ratings 10-15 mpg higher than the highest MPG ICE car ever produced.