[orange4boy]

Bringing voltage up from 12 to 18 made a large difference in FE on my alternatorless Previa.

I have finally had a chance to try running the Golden Egg with 18V. I have been given a set of used Trojan T-105s to play around with.

Disclaimer: 18V is actually too high so don't try this yourselves as I don't want to be held responsible for frying anyone's ECU. Cars are designed to operate in over-voltage conditions in the event of a regulator failure so I risked it. First casualty: the headlights. Everything else seems fine though.

The first results are impressive but I have not done a full tank yet, this comes only from MPGuino relative readings. I would love it if someone who commutes could try this. My observations:

1) Idle speed GPH while idling has gone from about .75 to .29. I think this is because the ECU was keeping the revs up to charge the battery as it was showing only 11.5 - 12.5V. CPU is probably programmed to keep 13.5-14.5

2) MPG while coasting/idling at highway speed. This has gone up from about 100 to 160

3) Highway cruise mpg has gone up too. roughly from 30 to 35. (more testing to be done here)

4) Idle is smoother and throttle response is better.

I always thought that the MPG seems to slowly drop with battery voltage but I didn't think it made such a big difference. What's exciting about this is that there are greater gains to be made from alternator removal that I had first thought.

The best way to go here would be either 2 8V batteries in series or a couple of 25A 12V-16V DC to DC up-converters in parallel and a couple of 12V deep cycle batts to run them.

Has anyone else tried running alternatorless at higher voltages? I can't do A-B-A tests myself but would love to see this done.