I have an Apollo brand 12 Volt Cooler/Warmer, designed to plug in to my car's 12 V cigarette lighter.

I am wondering if the power this device uses will significantly affect my car's performance or gas mileage. I have a 2010 VW Jetta 2.5 liter gasoline car.

The transformer for the 100-240 V AC connection (another option for running the device) says it is designed to output 4 A at 12 V DC. Since power = current x voltage, the transformer will output 48 W of power.

The transformer also says that it takes 60 W of power for the input.

  • Word of advice. Do no try it. Just after spending lots of money and hours of head ache with mine. Bought one 12v cooler box and damage two batteries new and damage the altinator of my Jeep, 2.2 santa Fe. – Save Jul 12 '18 at 21:08

You should not notice any difference. Here's why:

1 hp = 746 W. This means that 60 W is 0.08 hp.

The worst possible scenario from a load perspective is at idle. Assuming the engine is outputting a measly 5 hp at idle, the extra load would work out to 1.6 % of this value. The change in fuel consumption is barely sensible.

  • Is it so even though the energy is getting drawn indirectly from the engine through the alternator and the battery rather than straight from the engine? – NeutronStar May 23 '14 at 5:09
  • 1
    Joshua, it doesn't matter - 0.08hp is so low it has negligible effect. – Rory Alsop May 23 '14 at 8:29
  • @Joshua : the alternator gets power from the engine, so yes. – Zaid May 23 '14 at 10:30
  • 3
    Obviously, this assumes that you're only running the cooler when you're driving around. If you fire up the car just to make things cold, you're going to be wasting a lot of fuel. – Bob Cross May 23 '14 at 13:18

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.