Hey, who else has purchased a miracle automotive product only to find it didn't work? Here are a few that come to mind: I drove a '68 Impala from '78 - '84. When I got the car, the old 307 got about 200 miles to the quart of oil. I was pretty devout about changing oil every 2000 miles, and used only Quaker State 10W-30 for the first few years. Anyway, the first fall I had the car, I was in at a Sears Automotive shop and saw this product called Lubrilon. It was Teflon particles in motor oil, and was supposed to reduce friction and wear. The salesman told me 'that stuff works miracles' and that the mileage in his big Ford had gone from 6 to 8 MPG (Imperial gallons, not US). 33%! Wow, I was sold! I put down my $30 IIRC. (To put it in perspective, I was a university student working part-time in a warehouse for $2.95/hr.) The results were underwhelming ... I saw no increase in gas mileage, and no reduction in oil consumption. About two and a half years later, I purchased a Cagle fuel pressure regulator from the Minit-Tune shop where I worked as an oil change & tune-up tech. I pulled in $3.75/hr. (Classic Liberal Arts grad story.) The principle was that a mechanical fuel pump was designed to produce sufficient pressure for open throttle operation (5-7 PSI) but that at idle and cruise 1-1/2 PSI was sufficient. However, the fuel pump's unregulated pressure would overwhelm the needle & float mechanism in the carb at idle and cruise, forcing extra fuel into the float bowl. The Cagle spliced into the fuel line before the carb, and was regulated by vacuum from the intake manifold. High vacuum = low load = low fuel pressure requirement. Low vacuum = high load = high fuel pressure requirement. Again, underwhelming results ... no measurable change in gas mileage. That one was $92.50 plus tax. At $3.75/hr, that one ate up the better part of a week's wages. Fast forward to 1998. The Impala is long-gone. By this time I'm working in communications engineering, and there's light at the end of the financial tunnel. Several of my coworkers do a group buy on a platinum injection system. The idea is that if the precious metals in the catalytic convertor help complete the combustion process to clean up emissions, wouldn't the same metals, if injected into the intake airflow, do the same in the combustion chamber where they'll help engine efficiency? I'm skeptical ... significantly older, and slightly wiser. I talk to the guys who've bought these. They're all seeing incredible things - 22% improvement on the Caravan ... used to fill up the Protege every 5 days, now fill it up once a week, etc. I buy two, one for each vehicle. I'm out over $200 we can scarcely afford. My wage is better, but this is still 10 hours of gross wage. Again, nothing. If anything, mileage drops slightly in both vehicles. I talk to the guys again ... Mr 22% figures he might have been comparing city & highway mileage, Mr Fill-up-weekly-instead-of-every-five-days figures maybe he's driving less. GRRR! Finally, a few years ago, c. 2005, I buy a fuel warmer from Mr LaPointe, the acetone man. Again, no improvement. Oh well, I've had some fun, and learned about a few ways to not improve your mileage. I can't be the only one - who else has fallen for a miracle product that sounds credible? Did any of them actually work? And thanks for reading through this tedious post! P.S. The one thing I can vouch for? A ScanGauge which provides real-time feedback, and helps you adjust your driving habits accordingly.