How your battery affects your fuel economy
Everyone’s talking about fuel economy these days.
Even as gasoline prices fluctuate, drivers are trying to get the best fuel economy possible. And auto manufacturers are racing to hit the federal government’s new Corporate Average Fuel Economy (CAFE) standards, which aim to double present the average fuel economy of a manufacturer’s new cars to 54.5 mpg by 2025.
Those standards were started in 1975 when the American economy was disturbed by an oil embargo, and now it’s one of the most important numbers car buyers consider.
Your battery’s supporting role
Did you know the battery plays a part on how many miles per gallon you get?
It’s all about the horsepower.
An alternator rated at 100 amps requires about 2 horsepower. When a battery is undersized compared to OEM starting and reserve requirements, it requires the onboard charging system to draw more horsepower more often.
If the battery has too large of a capacity and becomes severely discharged, the vehicle’s charging system is working harder and longer – drawing more horsepower.
Penny wise, pound foolish
Let’s take a vehicle that requires a 600 CCA, 120-minute RC battery, as rated by the manufacturer.
To save money, a car owner decides to purchase a 400 CCA, 90-minute RC battery. The starting system requires 500 amps for 4 seconds on an extremely cold or hot day. Due to amps needed to start the vehicle, the battery discharges down to a much lower voltage and power availability, requiring further recharging (i.e. horsepower) for an additional time.
At that point, the battery is already affecting the mpg since the alternator has to draw more horsepower to recharge a weak battery.
The money the car owner thought he saved now goes into gasoline – and another battery because he shortened the life of the first one.
With many vehicles experiencing electronic-laden overload, having the quality battery with the proper power rating can reduce horsepower needs and result in slightly better fuel mileage.
In fact, to ensure the best fuel mileage, CAFE testers always charge the battery before running their tests.
That’s how closely your CCA is related to your mpg.
For the best gas mileage, choose a high-quality battery that’s the right fit. Then test it regularly and replace it at the first sign of deterioration.
Got a question for Mr. Battery? Send him a note at interstatebatteries.com/mrbattery.