Using the fan, heater

[1stToyota]

Originally Posted by BailOut

I wasn't going to do this as I have little patience for your overall attitude but I got bored on the drive home today and played around a bit.

What I found not only supports what we have been telling you over and over and over but also shows that the energy cycle is more impacting than any of us thought.

This is detectable even while hill climbing but it is easier on flat ground or on a decline unless you have a very steady throttle foot. All measurements were gained using a ScanGauge II. Its voltage measurement only goes to one decimal place so the measurements are rough but solid.

At "rest" and with the engine running the electrical system sits at 14.1 volts. Since my DRL was on turning on the headlights doesn't produce much of a difference by itself, but combining that with the stock radio on a volume setting of about 20 and using the blinkers was enough to knock the measurable voltage down to 14.0V. After about 2 seconds of this the voltage goes up to 14.2V for a while, which indicates that the alternator is clutching and producing a higher output. Once done the voltage drops back to 14.1V and will stay there if you stop the additional drains, otherwise it will repeat the cycle of dropping to 14.0V and charging back to 14.2V. Using the high beams can produce this effect almost immediately as it is a rather large draw on the electrical system, though not nearly as much as most aftermarket stereo setups, and the alternator clutches for longer to deal with it.

So I got to wondering how much this minor clutching of the alternator was dragging on the engine. I wasn't sure if it would be measurable or not. So I brought up the "load" meter on the SGII. It reads 40 at its lowest and 100 at its highest. Every single time the alternator clutched and produced 14.2V the load reading went up by 1. As soon as the alternator calmed down it went back to 1 lower number. The instant MPG display also drops 1-2% during this time.

These measurements mean that the effect of minor electrical drains in the Yaris isn't 0.1% as was arbitrarily suggested, but is more like 1.5-2%! It will be even more under heavy, constant loads from things like large sound systems, producing even more of a fuel economy drain.

So, there you have it. You wanted numbers and documentation, and I just gave you both. Anyone with an SGII can verify my findings.

I wasn't going to use one of your quotes, but I gues I will.

As best as I can remember, and adjusted for current topic...

"I need mileage logs for 3 tanks, using the radio, and 3 logs without the use of the radio, or your findings are meaningless"

You can do that if you like, but I've got better things to worry about than saving a few cents per year, as in not using the blower for the next 60 years.