Thor Forums

[FW28z]

Incredibly, on today's return trip, I averaged 9.6mpg.

I was careful to drive normally, and used the speed control whenever I could. I am getting the mpg reading from the ScanGauge.

Today's temperature and wind conditions were pretty similar to Friday's. But I think the only real difference is the return trip was a bit more "downhill" from the trip on Fri.

One other oddity is late last year, I swapped out the Garmin Ecoboost for the Scanguage, as it started acting flakey. But until that time, it had been registering around 9mpg. The Scangauge has never registered above 8.5mpg, either late last year, or before I put the tabs on this year. I put about 8 trips on the scangauge before installing the Air Tabs.

One thing I think might be causing this is the GPS shows about 2MPH faster than the Scangauge at highway speeds. I did a timed run between mile-markers on the freeway several times, and the GPS always read correctly - so the Scangauge reads a bit low MPH wise.

This might cause the descrepancy in the MPG readings between the Garmin Ecoboost and Scangauge, as of course, MPG is dependant on distance travelled and fuel burned. As the distance travelled in the Scangauge is likely different than the GPS, that is probably the thing causing the discrepancy.

However, even if the MPG rate has a small error between instruments, if I use one instrument for all of the testing, I should obtain reasonable accuracy as I am then measuring the difference the gauge is reading with or without Air Tabs, rather than an absolute value.

I did hesitate a bit to mention this because someone will say using two instruments is where the difference comes from, but that is not what I am doing. I am seeing the difference in the Scangauge by itself with/without Air Tabs, not between the Garmin and Scangauge instruments.

At any rate, I am very encouraged by all of this, and while I may not be able to keep my observation from having any bias, I am trying to control the environment as much as possible.

However, since vortex generators is sound science, I think I can safely say at this point that there is some improvement in using Air Tabs.