Quote:
Originally Posted by InsightfulRay
Thanks for your post. My last car was a 2006 Insight so I can appreciate the temptation to add VG's to that in hopes of benefits. I suspect the negative result they reported with the Insight is more about the small surface area of the rear of a GenI Insight (hence less surface area for any low pressure wake to act upon) plus the extreme aero tweaking that went into the Insight at the factory. They likely squeezed about as much as possible out of the Insight's CD short of the full boat-tail treatment our fellow ecomodder in Wisconsin has done.
Not a big fan of A/B drag tests. Personally, I don't trust short distance A-B-A testing which is why I'm doing a controlled tank to tank test. Really, "tank to tank" is a misnomer. I'm accumulating several tanks worth of fuel consumption data. My driving route, speed, air temperatures and number of warm-ups per tank are close enough that I have reasonable confidence that a significant improvement in MPG will be detectable. I keep exacting fuel consumption records so I have a solid benchmark for my Mini's fuel consumption. Thus far my first full tank refill (525 miles worth of driving) after installing the AirTabs has increased my fuel economy by 1.5 mpg. This is about what I was expecting. It works out to about a 3% improvement over no VG's. We'll see how I fare on the next tank. The improvement might completely disappear.  |
Cool--to me, it's all about measuring the variance in the control set and the experimental set, and seeing how many standard deviations apart they are. It'd be great to see the raw numbers from your last five pre-VG tanks and the first post-VG ones, as well as the placement of your VGs.