Three months ago, I installed a device on my car called the Blade which reduces emissions and is supposed to improve fuel economy. You can read about the installation here. First and foremost, the Blade is primarily an emissions-capturing device. As I have discussed before, this it does remarkably well as certified by this independent lab. Second, the Blade is reported to have a side benefit of improving gas mileage. Everyone wants to know “does it work?” I believe that it does, though I am still testing it.

Let me further qualify by saying that anyone who knows anything about tracking mileage knows that it is next to impossible to get consistent results outside of a lab. So many factors, including wind speed, wind direction, inclement weather, road gradient, road condition, luggage/cargo, and traffic can alter results from day to day. It takes a long time to establish a baseline.

Also, I should include a note about how I compute mileage - it’s old school. I have no fancy gauge to compute on-the-go or average mileage (this is a stock Scion, after all). I drive as long as I can on a tank of gas and then fill ‘er up! I divide the total miles driven that tank by the number of gallons used to fill the tank. I round that number up to the nearest tenth. I always fill the tank with the pump trigger on the lowest automatic setting and leave it until it shuts off automatically. I never top-off. I do try to use the very same pump at the same gas station, but can’t always do so for obvious reasons. For my highway tests, I fill up the tank right before entering the highway, then fill it up again as soon as possible after exiting. Then I similarly divide the number of miles driven by the gallons used to fill the tank back up. This is the best I can do.

I drive a 2006 Scion Xa with a manual transmission. You can find its EPA-rated fuel economy here. The Xa is rated by the government 27 MPG City, 34 MPG Highway, and 30 MPG Combined. I find these numbers to be consistent with my stock tailpipe. My mileage “pre-Blade” was an average of 30-32 MPG Combined. For the several months before the installation, I never saw my average above 32 MPG. Also, my drums, hardware, and cymbals go with me almost everywhere. They add a fair amount of weight which can only reduce my MPG, albeit slightly.

My typical mileage usage consists of approximately 25% short city trips, 60% highway stints of 15-30 miles at a time, and 15% mixed (where speed limits are higher but there are still stoplights). Due to my profession as a freelance musician, my travel is varied with occasional long-distance trips as well. Still, there are a few places I go on a regular basis, and they always include the Kennedy and Edens Expressways. Now, those of you who live in Chicago know that the Edens was a mess all summer! Reduced to two lanes, the traffic was routinely stopped or moving at less than 5 MPH. The back ups greatly affected the Kennedy as well. My usual commutes went from 20-30 minutes to anywhere from 40 minutes to well over an hour. Often I got off the highway and took very slow city streets. Naturally, this made my results very difficult to compare with my baseline. The construction started just before I put the Blade on, and it was only a few weeks ago that the Edens started to improve, eventually returning to normal. You will see this improvement in my results below:

• Tank 1    30.6 MPG (Blade not installed for full tank)
• Tank 2    33.8 MPG
• Tank 3    31.2 MPG
• Tank 4    32.3 MPG
• Tank 5    33.7 MPG
• Tank 6    30.9 MPG
• Tank 7    32.5 MPG
• Tank 8    34.8 MPG
• Tank 9    32.4 MPG
• Tank 10  34.6 MPG
• Tank 11  33.9 MPG
• Tank 12  34.0 MPG

In conclusion, I conservatively estimate the MPG improvement from the Blade to be about 2-3 MPG overall. I think it works much better on the highway where the numbers appear to be about 3-8 MPG better than EPA ratings. I consider the first several tanks, in which my mileage did not decrease any from my average baseline while my commute degraded significantly, as evidence of improvement. Once the Edens Expressway improved, my results became much more consistent, and higher than any I had seen previously. Even these modest increases represent a significant savings in fuel and dollars.

I welcome your own conclusions from my data, and will continue to track it and update it on this page. To make this a truly thorough investigation, I will take the Blade off when the filter needs to be changed. I will then track and post my mileage without the Blade for several tanks to see if there is an immediate reduction.