Today’s tip is along the same idea as the headlights tip, only it’s a little more broad.
Minimize the use of your car’s “electrical devices.”
Here’s what I mean by “electrical devices”:
- Rear window defrost
- Radio
- Navigational systems
- Dome lights
- Power locks and windows
- Plug-in DVD players
While this certainly isn’t an all-inclusive list, I think you catch my drift.
Anyway, the reason behind minimizing the use of these devices is when you use your car’s electrical systems, in a round about way you are using more gas.
This is because your car’s electrical systems are powered by it’s alternator (while the car is running), and the alternator gets it’s energy from the car’s engine. If you need the alternator to produce more power for the electrical systems, it’s going to sap more energy from the engine, meaning worse fuel economy.
Obviously, having a failing alternator will only exacerbate the problem.
So, long story short, if you can minimize the use of your car’s electrical systems, you should see a slight increase in your vehicle’s gas mileage.
{ 11 comments… read them below or add one }
This is simply not true …. and alternator is not operated on a clutch therefore it spins at the same speed no matter what is being used in the car. It is not on a clutch like the AC that just kicks in when the compressor comes on.
I agree with Josh’s comment, electrical draw has zip to do with fuel use. You can use your electrical system all you want, but the AC does reduce your economy. If you are serious about saving fuel, get your next vehicle WITHOUT an automatic transmission. They sap over 30% of the efficiency of the vehicle. No let’s see how many “greens” switch to manual transmissions. I bet there won’t be any. People are willing to give up efficiency for convenience. And that is the basic problem.
that is incorrect…although it barely makes a difference, the alternator will resist spinning when a load is placed on it from electrical devices, thus lower mileage, but the effects are minimal.
An increase in electric power use results in a lower system voltage (V=IR). To compensate, the voltage regulator increases power to the field coil. The stator now spins through a stronger magnetic field. It takes more torque to spin it, which makes the engine work harder.
The load put on the alternator does affect it as anonymous says, but unless you’re running some huge stereo system that’s drawing a big load, this difference is really too small to bother. There are a lot of other things you can do to increase mileage.
Having a manual trans is very handy, for example popping it into neutral going downhill or coasting to a stop. I laugh every time I see cars accelerate past me so they can hit the brakes at a light, and I coast up as it’s changing and never touch the brakes. My mileage went from 31 to 36mpg by just adding coasting to my driving whenever it’s a safe option.
According to my electrical engineer friend, electrical devices doesn’t directly affect the fuel consumption of a vehicle, since the alternator’s output is proportional to the engine’s rpm. Electrical devices cannot generate electromagnetic drag (the magnetic field the last Anonymous talked about) on the alternator since the alternator can only generate electrical energy output, but cannot accept any form of input into it. Electrical devices can only affect fuel consumption because of the added weight it brings into the vehicle.
Regor your elecrical “engineer” friend should go back to school.
Please do not post comments on posts you clearly do not understand
Regor and his engineer friend believe in the “Get Your Money for Nothing and Your Chicks for Free” school of engineering theory.
The electrical devices in your car have no direct relationship to gas mileage – except the AC. I have worked as an automotive engineer for over 30 years – I know what you are claimed is pure BS.
Only devices that put on additional drag on the motor will affect MPG. They include AC and power steering. You can’t turn off power steering – so that only leaves AC.
Try emptying your trunk of all your garbage, tuning up your engine, clean fuel injectors, replace dirty air filters, and properly inflating your tires – all these can increase MPG.
I can only hope that Regor’s friend and Tom are “exaggerating” their engineering credentials, otherwise the demise of American engineering and the Detroit automakers is easy to understand.
The idea that a device requiring electrical energy to operate gets it from anywhere other than the automobile engine by burning fuel is obviously incorrect. The only way it could be true is if the energy used to power the radio, etc., is otherwise being wasted, in which case what I stated above is even more true.
I suspect the answer to this may be something in the neighborhood of “not so much”–but while we’re talking electrical, does anybody know anything about these hyper voltage systems that (supposedly?) make your electrical system more efficient, thus increasing your fuel efficiency? I already hyper-mile my butt off, but am curious whether these things have any real value.