Debunking fuel-saving marketing, myths, etc

[theholycow]

How about it? Got any links debunking common myths about fuel economy (or other automotive stuff)?

From my meta-sig:
Tony's Guide to Fuel saving gadgets http://www.fuelsaving.info/debunk.htm
Gas Saving and Aftermarket Retrofit Device Evaluation Program http://www.epa.gov/oms/consumer/reports.htm
"Gas-Saving" Products: Fact or Fuelishness? http://www.ftc.gov/bcp/edu/pubs/cons...tos/aut10.shtm
Air filters http://www.fueleconomy.gov/feg/maintain.shtml and http://www.fueleconomy.gov/feg/pdfs/...02_26_2009.pdf

Just found this:
The Low-Down on High Octane Gasoline http://www.ftc.gov/bcp/edu/pubs/cons...tos/aut12.shtm

[GasSavers_maximilian]

Guy at my hardware store just bought some high octane gas for his Aveo to test the difference. I'll send him the link. Thanks! I've gotten him to come here, but don't think he's signed up yet, although he expressed interest.

[bowtieguy]

one of those links recommends using high octane for a few tanks if cleaning is needed. at least it suggests that is a better option than a fuel additive.

[zero_gravity]

yea i'm convinced that the best cleaning method beyond taking the engine apart and cleaning manually is to use a couple tanks of premium and just flog it

[shatto]

Is the point of 'Hypermiling' to be able to say you did it?

Do you not consider the cost of what you do and the return on your investment?

Where is scientific evidence that 'high octane' for a few tanks will actually 'clean' an engine? It does not properly combust in an engine designed and tuned for regular gasoline, so you are in fact, burning money you might better use elsewhere.

[dkjones96]

The EPA evaluation program makes for some good reading. I spent a couple days through and reading pretty much all of them.

As for cleaning out the engine, just beat on it and take it on a long highway trip every once in a while(at least two hours round trip). Premium does usually have more detergents but if you just put premium in the tank you aren't doing the engine any favors.

Engines were built to run hard. They don't dyno test them for hundreds of hours on end at wide open throttle because they are building them to run just off idle for 100k miles.

[theholycow]

I bet a $1 bottle of WalMart's SuperTech brand fuel system cleaner would do just as good a job of cleaning as a few tanks of extra-detergent high octane gas.

Really, I question whether they'd actually put more detergent in the high octane gas. I imagine that whatever kind of detergent it is, it's not a potent fuel, so it's diluting the gas; so many people who want or need high octane fuel use it for performance. It wouldn't make sense to dilute it more.

[GasSavers_RoadWarrior]

High octane = less bang... lots of people forget that!

It's only high performance in that it allows higher compression and/or more spark advance without detonation, which may offer higher power over lower compression/lower octane.

Three good ways to clean a motor, isopropyl alcohol, mineral spirits or water. IPA or MS may be put in the tank or snorted through a vacuum line, water should only be carefully snorted in a vacuum line, or misted into the intake. IPA or MS won't do anything for your fuel system if snorted in though, but can de-gum injectors if run through the tank. 4-8oz is a good cleaning dose. MS drops octane and IPA raises it. So if it's pinging use IPA, if it's not use either. "In tank" treatments work best with long highway runs and "italian tune ups"

[bowtieguy]

Originally Posted by theholycow

I bet a $1 bottle of WalMart's SuperTech brand fuel system cleaner would do just as good a job of cleaning as a few tanks of extra-detergent high octane gas.

i wouldn't put most additives in my tank, and ESPECIALLY not a wally world brand or the cheapest available.

BTW, i've heard mechanics that swear by the cleaning power of high octane vs low. just sayin'.

[theholycow]

WalMart's automotive fluids seem to be pretty decent, but I can understand being skeptical.

As for mechanics...I've heard them say all kinds of silly stuff, they're as bad as or worse than anyone else.