Gas additives?

[QC]

Re: Gas additives?

Sickwilly,

If you refer to my post you will see a reference to Low Heat Value (LHV) and High Heat Value (HHV). Bruce edited the subsequent numbers to LHV, but the first lines represent HHV. LHV is more of a "net" energy number and typically used in engine discussions. You must do all calcs in one or the other or it doesn't make sense. So . . . . what I used was LHV from the Department of Energy:

Fuel, BTU/lb, BTU/gallon
Gasoline, 18676, 116090
#2 diesel, 18394, 129050
Ethanol, 11585, 76330
Propane, 19900, 84500
Methane, 20263, 19800
Hydrogen, 52217, N/A

1 US Gal Gasoline = 116,090 BTUs x .15 = 17,413

1 US Gal Ethanol = 76,330 BTUs x .85 = 64,880

64,880 + 17,413 = 82,293 BTUs in a US Gallon of E85 (85% Ethanol and 15% Gasoline) So when comparing cost and efficiency you need to use the energy equalized figures. The other method is to use a Gasoline Gallon Equivalent (GGE) which would be 1.41 Gallons of E85 to equal the energy of 1 US Gallon of Gasoline (116,090/82,293 = 1.41). So that means that at 2.19 per gallon of E85, the actual energy needed to match a GGE would cost $3.09. Refer to my post above for the break even cost on E85. Hope this helps.

 

[sickwilly]

Re: Gas additives?

Thanks, that clears it up for me.

 

[Silvertip]

Re: Gas additives?

Sorry Dudes -- while your numbers are somewhat accurate, they are "test" numbers and not necessarily real world. The prices I quoted for fuel were for E10 and E85. Regular (non-blended) was $2.94 vs $2.74 for E10. There are those that contend no car will meet the manufacturers MPG claims. I will only say that I have never owned a GM car that did not meet its MPG claims. It turns out I returned from a 520 mile trip late yesterday afternoon. Keep in mind when I left on this trip the day before it was 23 below zero and -6 on the return leg. My round trip average on E85 was 24.7 MPG. Three adults in the car on the outbound leg and two on the way back. This same trip is made often running regular gas and E10. Although I've seen just a tick under 34 MPG that is an exception. The car typically provides 29 - 31 and you can take 30.5 to the bank on most trips using E10. Summer trips will show 26 - 27 MPG on E85. There are tricks to getting good fuel economy regardless what type of fuel you use or what type of vehicle you drive. A good driver can get better fuel economy if you "help" the cruise control. To explain: As a vehicle on cruise enters a hill the car slows a bit before the cruise control realizes this. Therefore it has to apply more throttle to make up for lost speed. If you leave the cruise control on and before you reach the hill, increase speed by simply stepping on the gas a tad and then gradually ease off again as you reach the mid point of the hill. You don't need to provide much help. Gaining 1 or 2 MPH on the flat or going downhill takes far less fuel than trying to make up 1-2 MPH going uphill. The smaller the engine the more help this is. That technique and not doing jack rabbit starts goes a long way to providing better economy. The gas pedal is a linear device -- not an ON-OFF switch. You left footed brakers need to take a lesson as well. You can tell these drivers because the brake lights are constantly flickering on and off because they have their left foot resting on the brake pedal. These folks also tend to complain about bad economy and how fast their brakes wear out. Gee -- I wonder why that is. Sorry I didn't get pictures taken of my fuel test today but I have it on my "To Do List". Just to maintain peace in this never ending discussion, I certainly am not proud of the government mandates regarding ethanol. But we have it -- so we must deal with.

 

[QC]

Re: Gas additives?

Silvertip . . . every SAE paper and OEM engineering department on the planet uses energy content calcs to evaluate any and all fuels and technologies. "Real world" vs. "test" does not eliminate laws of physics and chemistry. The numbers I have posted have nothing whatsoever to do with driving technique. They are clear and simple energy content. Whether you are buying crude, nat gas, bunker fuel, hydrogen or nitromethane; energy content is significant.

Also, your driving techniques work for all fuels, so the savings work for gasoline as well as E85 or plutonium . . . OK, maybe not plutonium

Please, please, I do this for a living. I know guys that believe they get 20% better fuel economy by adding moth balls to their gas tanks Does that make their experience more real than controlled tests that proves it does nothing?

BTW, who you calling two foot? I learned to drive with a stick. I use my left foot for braking in one situation only, retrieving a boat on a launch ramp . . .

 

[PeterMcG]

Re: Gas additives?

QC, for what it's worth, your explanation and sample calculation for the energy content and subsequent efficiency calculations were clear and straightforward.

Because of my educational background, I have had similar discussions with friends about the subject. Some people have a little difficulty wrapping their mind around the idea that a compound can have a higher octane rating AND yield less energy upon combustion.

 

[sickwilly]

Re: Gas additives?

Marathon gas stations around me in Middle Tennessee are starting to market their gas as being 100% gasoline. I tried a tank and was getting marginally better fuel economy until the great global warming cold spell descended on Middle Tennessee and I had to result in doing the Al Gore 20 minute car warm up before driving the kids to the bus stop every morning. (as an aside, its not been above freezing in Nashvegas, home of Al Gore, for over a weak now!).

I get a tank of E85 every once and a while when the price spreads. The only station close to me, unfortunately, often just makes the E85 20 cents cheaper, which is clearly not based on what they paid for it, but pegged to what they are selling their gas for.

As an additional variable, my Ford's manual (Sport Trac with the 4.0) says if you regularly use E85 you need to use the maintenance schedule for harder use - more frequent oil and filter changes. That also adds costs.

 

[triumphrick]

Re: Gas additives?

I'm in the process of buying a used boat, 1998 Four Winns 238 Vista, 5.0 OMC/Volvo SXDP. The current owner tells me he uses a fuel additive because of concerns about how ethanol could affect the engine, but he wasn't very specific about what problems might occur. Anyone have any thoughts on this issue??

Did ya get an answer yet?????

Probably not. I don't know what it would take to replace the twin 4 strokes on my rig because my fuel was spoiled, but I don't want to find out the hard way. VST pumps, filters, fuel rails on injected motors are all at risk with bad gas. Maybe over all these years that I have been using SeaFoam, I have tossed hundreds or thousands of dollars out the window for a product some here says I don't need. I love my peace of mind I get by using that stuff. From my early car days, where my old classics would set up in this Florida heat and humidity (yeah, I think where you live will make a difference) our gas tanks would foul. They don't by using this product.
It is used in all my lawn equipment motors, trucks and cars. Just a few ounces here and there. It is mixed a little leaner than called for, but I still get desired results using it. It is also available for doing a clean-out on a gunked motor.
One other thing not mentioned here yet, but as important as an additive would be the use of a good fuel/water separator. I change mine annually.

 

[Silvertip]

Re: Gas additives?

I guess my experiences with a flex fuel vehicle, boats, small engines and ethanol blended fuel have absolutely no meaning to anyone but me so I will end participation on this thread by saying I do not dispute the laws of physics. I simply contend that E10, E15 (when it arrives) and E85 are not the demons some folks have made them out to be. I've used the stuff far longer than most folks on this board and it simply is not an issue in our area of the country the way we operate our equipment and the manner in which it is used. We have a 130 degree temperature spread from summer to winter and very humid summers and to compensate for some very cold weather issues, flex fuel vehicles (at least GM) have block heaters as part of the package. I have yet to use it. I don't disagree that some folks will have issues with their older equipment when they transition from regular fuel to ethanol blends. The issues generally can be prevented through education and some relatively inexpensive changes and use of any of a number of available fuel system treatements. People thought it was the end of the world when emission controls came about too but a look back at the advances over those years which have provided us with far better power plants. The same holds true for other technological advances. In many cases we had to adapt but are better off for it. As for fuel economy and performance, no two people drive or operate equipment the same so there is no need to beat that horse any longer.

 

[bruceb58]

Re: Gas additives?

I don't think people here are disputing that it is OK to run e85. Its just that it isn't cheaper to use because of the energy content.

As far as flex fuel boats are concerned, please give an example of one.

 

[lprizman]

Re: Gas additives?

Startron at every fill up no matter what gas I am using.

 

[waterinthefuel]

Re: Gas additives?

Well then you're the only pilot I know that's never found water in fuel tank. I've drawn off as much as 4-5 ounces at a time during pre-flight inspections and that is from 20Gal tanks.

Perhaps you live in a very arid evironment, here in the deep south with high humidity and often little temp separation between the dew point it's VERY common to find water in aircraft fuel tanks.

Otherwise there'd be no point in that little clear plastic tube that every aircraft has for detecting water in the fuel or the drain cocks under every wing....

I also did a lot of flying in the SF bay area back in the early 80s... finding a few ounces of water in the tanks was not uncommon there either.

I was going to say the same thing. As a pilot and licensed airframe mechanic, I can say I have definitely seen water in fuel tanks. It is a well known fact that the more air you have in a tank the more water vapor and thus condensation can get in. That's not even disputed. I question a mechanic that believes otherwise. I live in south Louisiana and it's almost always 90% humidity here and airplanes with 3/4 full tanks can collect copious amounts of water in as little as an hour out on the ramp.

In school we pulled (with permission) a plane in that had been sitting on the ramp for 5 years. The tanks DID NOT leak. They had 25 gallons of water in them. The guy said he ran the plane until it was out of gas and then parked it. Every drop had to have gotten in by condensation alone, and it turned out to be 5 full 5 gallon buckets in there.

So please, don't say planes don't get water in the tanks. If you live in the desert, that might be true, but not everyone does and the FAA doesn't have a requirement that all tanks be able to be sumped at their lowest points for no reason.

 

[vicman]

Re: Gas additives?

I bought my boat in the late fall, and the dealer told me to use sta-bil in every tank of gas. He said sea foam was good stuff if you were going to use the whole tank in a short period of time. I told him I usually used sta-bil when I put it up for the winter, but he laughed and said I should use it year around. Has anyone ever heard of this?

 

[Texasmark]

Re: Gas additives?

Hey Guys,

Chill out. Life's too short.

Mark

(Yeah I know, I have a lot of room to be talking with my usual attitude. Ha!)

 

[Noob82]

Re: Gas additives?

Getting back to the original post regarding gas additives, I'd think any f.i. motor would have to develop some dirtying of injectors. Carb'd motors would also have a tendency to develop some decrease in performance d/t dirty jets. This situation is frequently encountered with your automobiles.

Given that, it would be advisable to use a good f.i. cleaner on occasion.

 

[Texasmark]

Re: Gas additives?

Getting back to the original post regarding gas additives, I'd think any f.i. motor would have to develop some dirtying of injectors. Carb'd motors would also have a tendency to develop some decrease in performance d/t dirty jets. This situation is frequently encountered with your automobiles.

Given that, it would be advisable to use a good f.i. cleaner on occasion.

Chevron and Shell both advertise additives in their to keep engines clean. Don't know about the others or regional requirements (EPA) on fuel stability. On occasion I have been in an engine (looking through the sparkplug hole) that has been run on currently available fuels and I am surprised at how clean they are. Currently induced additives must be working.

When I bought my current boat, the engine was 2 years old. It was ok, but seemed it should be doing better. That was about the time I joined this site and learned of Sea Foam. I had never heard of it before. Investigating I learned that it was a creation of a guy at OMC specifically for the problems you have in the marine environment, especially with 2 cycle engines. I started using it and haven't looked back. It works for me and yes I have seen the MSDS on it.

On all the rest of my engines (highway trucks excepted, use no additives in them) I don't use them all that much and fuel sits around. The results of dirty fuel systems has been beat to death on this site. I also realize that some of these problems are caused by equipment that has been sitting up for years; that is not the case with me.....but. Having had to clean up engine fuel messes in the past, I choose to not do that any longer.

For the little bit Stabil costs and the peace of mind it buys me, whether necessary or not, I am currently using it in these engines and will continue to do so. In my farm diesel, since I am planning on storing my fuel for up to 2 years, the Starbrite diesel enzyme is the answer.

My 2c,

Mark

 

[Keith7481]

Re: Gas additives?

Did ya get an answer yet?????

Probably not. I don't know what it would take to replace the twin 4 strokes on my rig because my fuel was spoiled, but I don't want to find out the hard way. VST pumps, filters, fuel rails on injected motors are all at risk with bad gas. Maybe over all these years that I have been using SeaFoam, I have tossed hundreds or thousands of dollars out the window for a product some here says I don't need. I love my peace of mind I get by using that stuff. From my early car days, where my old classics would set up in this Florida heat and humidity (yeah, I think where you live will make a difference) our gas tanks would foul. They don't by using this product.
It is used in all my lawn equipment motors, trucks and cars. Just a few ounces here and there. It is mixed a little leaner than called for, but I still get desired results using it. It is also available for doing a clean-out on a gunked motor.
One other thing not mentioned here yet, but as important as an additive would be the use of a good fuel/water separator. I change mine annually.

Yep, I did, and I really appreciate all of the comments and ideas, one of the best reasons to have a forum like this.