I did not see a thread for failure stories so here is mine:
First of all if you want to skip a short background story skip to second paragraph
Few years ago (2008) i graduated from college and bought my first car (impreza). car was/is very nice with no problems and has gotten me home through the worst winter storms and plus have had lots of fun messing and modding it. throughout my ownership i fell in love with engines, transmissions, exhausts, pulleys, belts, flywheels and all the other nuts and bolts. so with this i started to really get into auto world by reading perhaps 400-500 articles so far on various car parts and auto techs. After i became an internet engineer, i started to actually use my hands: fluid changes, brakes, shock/struts, ECU flashing, diagnosing, engine builds (had a friend help) and various other works. I can say that my car is perhaps my biggest hobby after golf lol. anyway long story short, i recently focused on solving my horrendous fuel economy problem. i was only averaging 21mpg around town and about 17mpg in harsh winter conditions. My Father achieves the same numbers with a turbocharged engine making 70 more horses and carrying 1000lbs more weight. I thought the mods might have something to do with it but it turned out it was NOT the modes. It's the car and maybe the way i drive?
So i came here and studied the 100 or whatever number of ways to improve fuel efficiency. my numbers started to improve but only slightly so and i was NOT really paying less at the pump with oil prices on the rise. Not satisfied i looked for more hardcore methods to improve my numbers. Then I came across a
brake specific fuel consumption thread on this website and for the past 6 months (and i really mean 6 months) i really got in to it. i read almost every page on BSFC on the net and tried various methods (by looking at a subaru bsfc chart) to improve my mpg during pulse or acceleration. The change was instead of being easy on the throttle i was slightly more aggressive
to accelerate (+80% load at 1500rpm-3000rpm vs 55-60% at 2500rpm). This did not help. in fact i learned from my log that accelerating at low rpms with high load was the culprit in my 'bad days'. I even tried an experiment and actually posted the results here and it proved to me that the lower the load, the better my fuel consumption. This is despite the fact that my car doesn't enrich mixture or go open loop unless above 4000rpm.
Anyway i have failed with BSFC and the gain from other tips such as engine off coasting or off at red lights have been too little to be worth the trouble. The only significant gain was maximizing coasting coupled with drive in lane with least resistance. Drafting was also great but i stopped doing that for safety reasons and my UEL headers scared/concerned lotta truck drivers. One of them actually pulled over once probably thinking that the noise was from his truck haha. i think i will go back to driving my car the way i used to
