trackermpg
06-07-2008, 12:01 PM
I had to do my "big" commute" (150 r/t) three times this week. Since this was my first consistent commuting since I got the SG, I wanted to take a serious look at how my modified top and new rear skirts were really doing. First two days I drove fairly "steady state" cruising speeds similar to how I had always driven: speed limit -10, neutral glides on our local hills when practical, FAS only to/at stops, and verified I'm up ~4mpg with those mods. Cool deal for less than $15 in duct tape and coroplast.
My daughter helped me tuft the back windows and the front wiper deflector shield to visually verify flow patterns. Since the wiper deflector indicated fairly disturbed flow patterns, we removed it at our gas stop, tufted the trailing edge of the hood and wiper blades themselves, and found there was little difference in flow. Decided to buy the "single arm" blades next time and call it good for now. We did verify however that we have unseperated flow almost continuously from front to back over the top that once was square. Version 2 is a go and will be Coroplast with a continuous smooth curve all the way down.
Then yesterday I got adventurous. I worked on P&G (NICE-on) speed ranges. Max speed 45. FASed 4 times each way at mandatory stops. Hit every light green. Had a 15mph tailwind going north, headwind coming home (hate when that happens). Had 44.1mpg for the first leg - I was over 45 until I had 20 miles of interstate during moderate rush hour so I had to drive 50 at times with very few glides. Same rush hour for first 15 miles of trip home. The headwind kicked my a__ and could only manage 37.6 coming back. Since my 13 yr old daughter is getting into the concept and was with me for the trip home, and I didn't want to alienate her completely, I let her use intermittent AC since it was 93F outside. For some reason taller, square front cars don't glide well with strong headwinds, and teenage girls don't think it's so cool to sweat????
Round trip total: 152 miles, 40.8 mpg :cool:
Last tank 39.2. Closing in on my first major goal of 40+ tank.
Next goal: 44
It occurred to me that once I dial in my P&G (NICE-ON) speed ranges and improve my acceleration techniques, and after a couple of remaining and desperately needed aero cleanups (lower front end, rear under bumper, and mirrors) - I could conceivably hit 47. That's 200% (original) EPA combined.
Thanks again everyone for the encouragement and advice. This process has been enjoyable in many more ways than just saving fuel.
My daughter helped me tuft the back windows and the front wiper deflector shield to visually verify flow patterns. Since the wiper deflector indicated fairly disturbed flow patterns, we removed it at our gas stop, tufted the trailing edge of the hood and wiper blades themselves, and found there was little difference in flow. Decided to buy the "single arm" blades next time and call it good for now. We did verify however that we have unseperated flow almost continuously from front to back over the top that once was square. Version 2 is a go and will be Coroplast with a continuous smooth curve all the way down.
Then yesterday I got adventurous. I worked on P&G (NICE-on) speed ranges. Max speed 45. FASed 4 times each way at mandatory stops. Hit every light green. Had a 15mph tailwind going north, headwind coming home (hate when that happens). Had 44.1mpg for the first leg - I was over 45 until I had 20 miles of interstate during moderate rush hour so I had to drive 50 at times with very few glides. Same rush hour for first 15 miles of trip home. The headwind kicked my a__ and could only manage 37.6 coming back. Since my 13 yr old daughter is getting into the concept and was with me for the trip home, and I didn't want to alienate her completely, I let her use intermittent AC since it was 93F outside. For some reason taller, square front cars don't glide well with strong headwinds, and teenage girls don't think it's so cool to sweat????
Round trip total: 152 miles, 40.8 mpg :cool:
Last tank 39.2. Closing in on my first major goal of 40+ tank.
Next goal: 44
It occurred to me that once I dial in my P&G (NICE-ON) speed ranges and improve my acceleration techniques, and after a couple of remaining and desperately needed aero cleanups (lower front end, rear under bumper, and mirrors) - I could conceivably hit 47. That's 200% (original) EPA combined.
Thanks again everyone for the encouragement and advice. This process has been enjoyable in many more ways than just saving fuel.