Busted/Confirmed Mods

[95metro]

I was just thinking that this may be a good Sticky for curious users/lurkers.

Acetone:
I say it's busted (I tried it once, but FE went down due to weather)
http://www.fuelsaving.info/acetone.htm
http://www3.telus.net/metro/log/nov0305.htm
http://www3.telus.net/metro/log/nov1805.htm

Aerodynamic Mods (general):
Confirmed
http://www.kenworth.com/brochures/FuelEfficiency.pdf

Air-Bleed Devices:
??? (Bad for pollution though and illegal in most areas)
http://www.fuelsaving.info/air_bleed.htm

Alternator/Accessory (AC, Power Steering, etc.) Belt Removal:
Confirmed
http://www.gassavers.org/showthread.php?t=1074

Boattail:
Confirmed
http://www.greencarcongress.com/2005...at_tail_d.html
http://www.maxmpg.org/the_cap.html
http://www.nasa.gov/centers/dryden/p...ain_H-2283.pdf
http://www.osti.gov/fcvt/2000-01-2209.pdf

Caulking:
Really hard to test - how would you A-B-A it? (Hmmm...Scotchtape? Might be crazy enough to work! Thanks zpiloto!)

Driving Technique:
Confirmed...over and over and over

Electrical Mods (grounding/stabilising):
Plausible?
http://www.fuelsaving.info/electric.htm

Ethos:
Busted
http://www.gassavers.org/showthread.php?t=908&page=2
http://www.gassavers.org/garage.php?do=viewgaslog&id=28
http://www.fuelsaving.info/ethos.htm

Front Wheel Skirts:
TBT (to be tested) (IMO most aero mods work)

Fuel Catalysts:
Busted
http://www.fuelsaving.info/catalysts.htm

Grill block:
confirmed
http://www.metrompg.com/posts/grille...ing-part-1.htm
http://www.metrompg.com/posts/grille...ing-part-2.htm

Hydrogen Generators/Injectors:
Plausible? (good theory, but impractical?)
http://www.fuelsaving.info/hydrogen.htm

Ignition Enhancers:
http://www.fuelsaving.info/ignition.htm

Intake/Exhaust Mods:
TBT

Increased PSI:
Confirmed (need a link)

K&N/High Flow Air Filters:
busted
http://www.metrompg.com/posts/air-filter-part-1.htm
http://www.metrompg.com/posts/air-filter-part-2.htm

Lightweight oils:
TBT

LPT (Light Pressure Turbo):
Confirmed
http://www.autozine.org/technical_sc...h_engine_3.htm
http://en.wikipedia.org/wiki/Turbocharger
http://autospeed.drive.com.au/cms/A_2664/article.html

LRR (Low Rolling Resistance) Tires:
Confirmed
http://www.greenseal.org/resources/r...resistance.pdf

Magnets:
Busted
http://www.fuelsaving.info/magnets.htm
http://www.kirotv.com/consumer/2220354/detail.html

Mirror removal:
TBT (monitor system electrical load may outweigh benefits IMO)

Oil Additives (Slick50, Duralube, etc.):
Busted
http://www.fuelsaving.info/oil.htm
http://www.carbibles.com/additives.html

Platinum Injection:
Busted
http://www.fuelsaving.info/platinum.htm
http://www.cbc.ca/consumers/market/f...pvi/index.html

PCV Catchcan:
TBT

Rear Wheel Skirts:
Confirmed
http://www.metrompg.com/posts/grille...ing-part-2.htm

Tire Pressure (increased):
Confirmed
http://www.gassavers.org/showthread....highlight=tire

Undertray:
Confirmed (need a link)

Vortex Generators:
Busted
http://www.fuelsaving.info/turbulence.htm
http://www.kirotv.com/consumer/2220354/detail.html

WAI (warm-air-intake):
Jury is out - may be vehicle dependent or mostly improve winter FE
http://www.metrompg.com/posts/wai-test.htm

I'll think of more, but please add whatever you feel like or mods you would like to see busted/confirmed.

Also, I saw an older Mythbusters last night that I hadn't seen before. They tested AC on vs windows open FE. I think their testing methods left a lot to be desired and they should have run it more than once, plus they only tested at 45 mph due to safety conditions on the track. Windows open won by traveling an extra 30 miles on 5 gallons of gas. It's a large enough margin that I'm certain it would be fairly consistent, but I'd like to see the same test at higher speeds (and swapping methods per vehicle, and repeatability, etc).

EDIT: Plus they should have tested the difference with no AC with the windows up.

[Mighty Mira]

Undertray: Confirmed.
Boattail: Confirmed.
Increased PSI: Confirmed.
LRR Tyres: Confirmed?

Caulking, Front Skirt, Mirror removal and camera replacement, need testing.
Deflectors, need some testing. (That would be front wheel, rear wheel, windscreen wiper)

Vortex Generators: Jury Out?

[LincolnW]

I think this is an excellent idea considering I am new and have been reading through tons of threads to pick up bits of information.

As far as the windows down and AC test. I have tested that in my car a number of times. Unfortunately I didn't take any real measurements but I can tell you this... my FE went down considerably when I used AC and had the windows up. I droped about 5mpg. But, when I had my windows down and AC off I didn't notice a significant drop in MPG at all.

But like I said, this wasn't much of a scientific test. I just drove one tank of gas (a week) while using AC, and one tank of gas driving with the windows down.

It also could be because my AC compressor is old and when I turn the AC on I can feel a significant drag on the engine and loss of performance. I know that a loss of performance is to be expected with AC, but on my car is seems much larger than normal.

Anyways, I vote that it's more efficient to drive with the windows down rather than up with AC. Plus the AC system ads like 100lbs to the car and removing it might increase the FE even more.

[krousdb]

Originally Posted by 95metro

Ethos: looks like it's busted

Busted

[95metro]

I'll try to reorganize my first post later. If you have links outside of gassavers please post them.

[diamondlarry]

Originally Posted by 90CivicStandard

I think this is an excellent idea considering I am new and have been reading through tons of threads to pick up bits of information.

As far as the windows down and AC test. I have tested that in my car a number of times. Unfortunately I didn't take any real measurements but I can tell you this... my FE went down considerably when I used AC and had the windows up. I droped about 5mpg. But, when I had my windows down and AC off I didn't notice a significant drop in MPG at all.

But like I said, this wasn't much of a scientific test. I just drove one tank of gas (a week) while using AC, and one tank of gas driving with the windows down.

It also could be because my AC compressor is old and when I turn the AC on I can feel a significant drag on the engine and loss of performance. I know that a loss of performance is to be expected with AC, but on my car is seems much larger than normal.

Anyways, I vote that it's more efficient to drive with the windows down rather than up with AC. Plus the AC system ads like 100lbs to the car and removing it might increase the FE even more.

What I've heard on the windows up or down A/C thing is: 50 mph or below it's better with the windows down and A/C off. Above 50, it's better to have the windows up and A/C on. Thoughts? Opinions?

[95metro]

Originally Posted by diamondlarry

What I've heard on the windows up or down A/C thing is: 50 mph or below it's better with the windows down and A/C off. Above 50, it's better to have the windows up and A/C on. Thoughts? Opinions?

That's what I kind of thought about the Mythbusters test. It seemed like they were testing very near the balance point. There has to be some particular speed where the vehicle would get the same mpg windows open vs AC on.

Like I said, Mythbusters didn't do enough testing at enough speeds. The results would have varied through 45, 50, 55, 60, 65, and 70 mph and they probably would have found the balance point in there somewhere.

And even then it would only be correct for the specific SUV they used. The more I think about it the worse their test gets. This is the first time I've strongly disagreed with one of their tests.

[95metro]

Ah, yes, the PCV catchcan. I'll call it TBT (to-be-tested) until someone points me to some results.

[GasSavers_Jack]

Originally Posted by 95metro

Ah, yes, the PCV catchcan. I'll call it TBT (to-be-tested) until someone points me to some results.

The catchcan sounds great in theory. I am not sure that we will ever get solid documentation that it works but I figure it cant be doing bad.

[95metro]

I can't see the benefit being huge from the catchcan, but possibly some. It may be impossible to test since the benefits might be seen over time and time tests are nearly impossible to quantify due to the variables.