Testing difference in fuel economy....

[thunder550]

Hey guys, I am going to be testing out one of those fuel saver devices from a sponsor over at GMFullsize.com and I wanted to see what you though would be the best way to do it. I got the custom MPG PID set up and I have been scanning with it, and I made a table of VSS vs DYNAIR g/cyl, and another of RPM vs DYNAIR. Do you think that driving around and filling in these tables before and after will give me a good idea of whether or not the fuel economy has increased? I was thinking that I can do a before and after table and copy them into Excel and calculate the differences across the whole table. I figure this removes driving style from the equation.

Here is the thread, in case anyone cares to dig through all 6 pages of arguments:

http://www.gmfullsize.com/forum/showthread.php?t=54038

I don't care about how many miles per tank of gas I get, that is subjective and changes with driving style. I am trying to remove driving style from the equation all together, and get down to how much fuel is consumed based on varying engine loads.

I am somewhat skeptical of this thing (although I do hope that it really works), and I know others are, so please keep personal opinions about the product itself out of the thread and let's concentrate on how best to test it. Do these tables sound like they will work ok? Should I be using MAP pressure instead? Thoughts on different testing parameters?

[white2001s10]

It's a knock-off of the "fuel-catalyzer" and the original "vitalizer" product that came out in the early 90's.

I have already tested it very thoroughly. It does absolutely nothing.
You will get good practice by going ahead and completing your tests, so please go ahead with that. You will be getting your money back in the end though.

When I say thoroughly I mean I tested for fuel usage and power output on both EFI and carbureted vehicles. As far as I'm concerned it had its fair day in court and now should head straight to jail.

[kbracing96]

Hey guys, I am going to be testing out one of those fuel saver devices from a sponsor over at GMFullsize.com and I wanted to see what you though would be the best way to do it. I got the custom MPG PID set up and I have been scanning with it, and I made a table of VSS vs DYNAIR g/cyl, and another of RPM vs DYNAIR. Do you think that driving around and filling in these tables before and after will give me a good idea of whether or not the fuel economy has increased? I was thinking that I can do a before and after table and copy them into Excel and calculate the differences across the whole table. I figure this removes driving style from the equation.

Here is the thread, in case anyone cares to dig through all 6 pages of arguments:

http://www.gmfullsize.com/forum/showthread.php?t=54038

I don't care about how many miles per tank of gas I get, that is subjective and changes with driving style. I am trying to remove driving style from the equation all together, and get down to how much fuel is consumed based on varying engine loads.

I am somewhat skeptical of this thing (although I do hope that it really works), and I know others are, so please keep personal opinions about the product itself out of the thread and let's concentrate on how best to test it. Do these tables sound like they will work ok? Should I be using MAP pressure instead? Thoughts on different testing parameters?

ROFLMAO:muahaha:You, doing fuel mileage testing, HA HA HA, that funny!!

I though your truck got gallon per mile LOL!!!

[thunder550]

It's a knock-off of the "fuel-catalyzer" and the original "vitalizer" product that came out in the early 90's.

I have already tested it very thoroughly. It does absolutely nothing.
You will get good practice by going ahead and completing your tests, so please go ahead with that. You will be getting your money back in the end though.

When I say thoroughly I mean I tested for fuel usage and power output on both EFI and carbureted vehicles. As far as I'm concerned it had its fair day in court and now should head straight to jail.


I didn't pay for it, so I'm not worried about losing anything except time. Was the one you tested from this same company?

[thunder550]

ROFLMAO:muahaha:You, doing fuel mileage testing, HA HA HA, that funny!!

I though your truck got gallon per mile LOL!!!


Haha oops I guess I need to start logging GPM instead eh?

[kbracing96]

Haha oops I guess I need to start logging GPM instead eh?

LOL, I though your truck was into fuel consumption, not fuel conservation:muahaha:

[dfe1]

When you get done with this test, let me know. I have some cow magnets, a force cyteratus and a turbo encabulator you can test. Seriously, I think the best thing to do is find some straight and level highway, drive at a specific speed and log throttle position, pulse width, vehicle speed, MAP and your mpg pid. That should show any differences, if they exist. If it's hard to find flat and level roads, you could go on an interstate, set the cruise control and log. Just about all of the magical devices I've tested do little or nothing, but every once and a while, you get a surprise.

[white2001s10]

I didn't pay for it, so I'm not worried about losing anything except time. Was the one you tested from this same company?


Different company, same item.

I do a lot of fuel & mileage testing and it's true that almost none of the devices work.
Lately I've been testing acetone as an additive.

Some people running in closed loop mode can see differences in fuel trims while fuel-mileage testing.
You can also compare the averages of some PIDs like the TPS if you're using cruise control for the exact same stretch of road.

I'd try to do the testing within as narrow a time period as you can to negate differences in temperature and air density.

[thunder550]

Anyone...other ideas on what PIDs I should be looking at? What maps should I set up?

[thunder550]

Different company, same item.

I do a lot of fuel & mileage testing and it's true that almost none of the devices work.
Lately I've been testing acetone as an additive.

Some people running in closed loop mode can see differences in fuel trims while fuel-mileage testing.
You can also compare the averages of some PIDs like the TPS if you're using cruise control for the exact same stretch of road.

I'd try to do the testing within as narrow a time period as you can to negate differences in temperature and air density.

What have you found with the acetone? I have been wondering about that for a long time.

[white2001s10]

Well I can't say too much that's concrete yet until getting more results and running additional and different tests... but

I can say that acetone defintately changes the way the fuel burns in the engine, and the % concentration seems to be critical as they say it is.

I've measured significant differences (improvements) in cold starting and the warm-up cycle with the acetone. Small concentrations seem to have the effect of lowering the fuel octane, or increasing the volatility of the fuel. At these low concentrations I have yet to measure a positive increase in fuel mileage with mixed-load testing, though I would guess the mileage would increase measurably for low-load conditions.

At higher concentration the volatility seems to go back down, relatively restoring the octane value of the fuel. At the same time the measured AFR (open-loop system) swings to the rich side, thus allowing fuel to be cut back to get the AFR back to its original value. This would lead one to think better fuel mileage, but I have not got positive data on this yet. The same test in a closed-loop system has actually shown a decrease in fuel mileage.

I have to say inconclusive so far, but definately no positive results in mileage yet. I'd like to have everything figured out in more detail before stating anything that I would think is fact.

[dfe1]

Hey guys, I am going to be testing out one of those fuel saver devices from a sponsor over at GMFullsize.com and I wanted to see what you though would be the best way to do it. I got the custom MPG PID set up and I have been scanning with it

Care to share your MPG pid?

[kbracing96]

Try this thread ;)

http://efiforum.iqd.co.nz/showthread.php?t=1667