[ewdysar]

Siding on the "science" side, I would also be interested in any measurable effect of adding this component.

As far as short term changes in calculated mileage, I have observed more than 10% variance in fuel economy between tanks of gas, with no modifications at all (hmmm, I did the A/C-defroster mod, and my last few tanks have been better, even though I haven't used the defroster setting since.) I've made a couple of posts on my theories concerning those fill variances in the Eco-Fit forum.

Checking the electrical system waveform and logging the system voltage under operating conditions might be able to identify if the VS has any effect. I'm not an EE, nor do I play one on TV, but I would believe the theory that it might just clip voltage spikes, if it did, the result would be cleaner power.

Eric