Originally Posted by rangerbentman
Has anyone tried any store bought mileage enhancer (Hydroxy ) and had success with it ?
EDIT: Oops, after writing all that info below (the line), I realized (after the fact) that you were talking specifically about "hydrogen" (water) based fuel economy add-ons, not just any fuel economy enhancer. My note, below, was about various "store bought" products that IMHO really do help FE, however none of the products I mentioned are based upon using water...
NOTE: Using "water injection" to get steam (and therefore extra power/push) off the hot pistons, can in theory help FE (but could be PITA to get properly designed). But OTOH there are a lot of products on the market that CLAIM to convert water into hydrogen (and oxygen), and then use the hydrogen to improve FE. The latter claims are almost certainly "snake oil", BECAUSE while you can convert water into hydrogen and oxygen, the energy required to do so is guaranteed (by the laws of physics) to be GREATER THAN any energy you recover by burning the hydrogen in your engine (hydrogen being a combustible fuel)!
I've had some success with:
"FP Plus" from http://www.lcdinc.com/fuel.htm
FP Plus is primarily a (slow) fuel system cleaner and lubricator (which I first heard about on the "Bob Is the Oil Guy" forums), but it seems to give some people's cars a little extra power and FE. In my case the extra power is small but a little noticeable to me (I have tried with/without the additive in the tank, and I slightly prefer the behavior with it in the tank). Also I've watched my gas logs during those experiments, and it seems to make a small (maybe 1 or 2) MPG difference. This difference isn't enough to write home about (or even enough difference to "prove" that this isn't just statistical error), but enough difference to make me believe the stuff is real, and to justify to me the cost (I think it works out to a little under $0.50/tank for me) given today's gas prices. And that's especially true, as while it's not a octane booster per se, it does make my car much "happier" on lower octane fuel (then it is without the additive). So I can almost pay for the cost of the additive, just on the saving I get vs buying higher octane fuel...
NOTE: FP Plus is actually cheaper to use, and (in my experience, and the experience of several other BITOG forum members) seems to work slightly better than their older FP60 formula. And while FP Plus is more per ounce than FP60, you only use 1/2 as much. As a result, FP Plus is actually less per gallon of gas treated than FP60 costs. So if you are interested in either of these products, you might as well go with the newer FP Plus, as it's actually cheaper to use, and works a little better (a win-win).
Auto-RX from http://www.auto-rx.com/
Auto-RX is mostly a very slow/gentle cleaner that you put in the oil. Many people over on the BITOG forums rave about the stuff, because a cleaner engine/transmission/etc just works better (more performance, better FE, ect). And the thing that makes Auto-RX unique as a cleaner, is that it's designed to NOT lower lubrication while cleaning (unlike virtually all other engine cleaners on the market). I've personally used the stuff as a cleaner, and (in the few cases I've tried it) it seems to work very well to revive engines, auto-transmissions, etc. In addition, I've started using their so-called "maintenance dose" in my engine oil. This is a smaller dose (than the full cleaning dose) that is designed just to help keep things in tip-top shape. Don't know how much (if any) that maintenance dose is directly helping my FE, but at least it's helping to keep everything in my engine clean.
Good synthetic oil and premium oil filtration (from Amsoil):
Good synthetic oil seems to be an all around win, as far as I can tell. On the few cars I've tried it on, a good synthetic seems to give more "power" (nice, but not really the point of this forum), slightly better FE (not huge, but others have reported that effect as well), a cleaner engine (most good synthetics don't have the build-up problems that conventional oils do), AND more protection against extreme driving conditions (including any attempts to allow the engine temp to raise more than stock, as a way to improve FE). In addition, when combined with premium synthetic micro-filtering on the oil, synthetic oils can (safely) last much longer intervals than conventional oils (it's not uncommon for me to go 10-15 thousand miles between oil changes, for example). That last fact alone, can actually bring the cost of good synthetics (and good filtration) down to LESS THAN the costs of using conventional oils/filters with conventional change intervals (as while the premium oil and filters are noticeably more costly than conventional parts, the fact that you change them less often can actually make the cost/mile lower with the premium synthetics/filters).
It's silly to use premium oil with conventional oil filters, as dirt in the oil kills most oils (even conventional oils) before most other oil breakdowns. So why go with fancy (long lasting) oil, if the dirt is going to ruin the oil before those expensive/fancy oil formulas otherwise wear out? So you really do want to go with some of the fanciest oil filtration on the market (for example, I use both Amsoil EAO synthetic micro-filters AND a fine (aprox 2 micron) bypass filter on my car), if you want premium oil to last. It will be initial "sticker shock" for top of the line oil filtration, but premium filtration can really pay for itself in the long haul.
I use Amsoil oil and synthetic filters, because I looked around for what was the premium stuff on the market, and found independent (at least didn't appear to be sponsored by Amsoil, or their dealers) tests (mostly on the BITOG forums) that showed that they had some of the best performing oils and filters on the market. And while I don't have nearly that level of test equipment, my subjective results (from using the stuff on personal vehicles) is that the cars/trucks in question seem very happy (better FE, more power, easier start in the winter, etc) with the results.
Which is why I went and got myself approved as a dealer for Amsoil last year. Among other things, that does allow me to get stuff at a considerable discount vs full retail. But it also should allow me to offer some specials to gassavers members as well. So if anyone is interested in trying some Amsoil products (or just chatting with me as to what I've tried of theirs, and how it worked for me), just send me a PM and I'll be happy to work with you. If not, oh well, I certainly won't be "quiting my day job" (to live off of selling Amsoil) anytime soon...