Comments on: Fuel Economy Tip – Reduce the Use of “Electrical Devices”

By: Igor

Igor — Fri, 26 Feb 2010 00:33:15 +0000

According to Audi, the new A5 reduced fuel consumption by being more electrically efficient. So its pretty clear to me that it does make a difference.

“Another innovation is an energy recuperation system that takes energy recovered during braking and deceleration and stores it temporarily in the battery. This can reduce fuel consumption by 3%.”

Note, this is on a GAS or DIESEL powered A5, not a hybrid.

By: Elle

Elle — Mon, 13 Jul 2009 21:58:17 +0000

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.

By: Rob

Rob — Tue, 07 Apr 2009 02:27:00 +0000

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.

By: Tom

Tom — Wed, 06 Feb 2008 16:18:42 +0000

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.

By: Rob

Rob — Tue, 30 Oct 2007 17:52:47 +0000

Regor and his engineer friend believe in the “Get Your Money for Nothing and Your Chicks for Free” school of engineering theory.

By: Anonymous2

Anonymous2 — Tue, 30 Oct 2007 16:51:50 +0000

Regor your elecrical “engineer” friend should go back to school.
Please do not post comments on posts you clearly do not understand

By: Regor

Regor — Wed, 03 Oct 2007 09:40:14 +0000

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.

By: Pal

Pal — Fri, 08 Jun 2007 21:21:02 +0000

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.

By: Anonymous

Anonymous — Fri, 25 May 2007 21:15:39 +0000

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.

By: Anonymous

Anonymous — Wed, 11 Apr 2007 08:44:50 +0000

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.