You can pretty much bet that no matter what the true story is, someone's making a LOT of money off of it. US taxpayers currently subsidize ethanol producer to the tune of 51 cents a gallon. Oil companies made mtbe(a byproduct of oil production and methanol) but stood to lose their behinds in legal action when mtbe was found to be a carcinogen. In 06 oxygenates were no longer required in gasoline but they still needed to pass emissions standards, which they couldn't do without an oxygenate additive of some type. This is only what I've read, so only the bad half is probably true. Mike
i have a radius 42 that was given to me. Before I got it it never tasted naptha. It had run on regular since it was bought including the leaded type in pre unleaded days. As far as I know the only maintenance its ever had was me painting the can. Still runs fine and keeps up with a 123r in a 1 litre boil time
Hi Guys, Somehow we drifted from my interest in the clogging of stoves by gas additives into the economics and environmental impacts of ethanol. Here in Israel ethanol is unheard of. Gas pump fuel is free of ethanol. Still, I do not understand anlrolfe statement: "Ethanol has a lower vapor pressure than gas and can lead to high tank pressure and SVR activation." If the vapor pressure is low, why will it increase tank pressure? My logic says the tank pressure should decrease, not increase. Yonadav
Vapor pressure of gasoline will vary regionally and seasonally so as to remain fairly constant. Gasoline, including its additives, will be a more volatile blend in colder climates and less so in warmer climates. The factors balanced for these blends are engine starting performance, vapor lock potential, and environmental air quality. Though the vapor pressure of ethanol is constant at a particular temperature and altitude, the vapor pressure of gasoline will be altered with different formulations to achieve the best balance of the aforementioned factors. Thus, don't use winter gas in the summer if your stove tank gets hot. Conversely, you may have a tough time getting a self pressurizing stove up to full power in the winter if using a summer blend. That said, I have no data on stove performance to back any of this up. It would make an interesting experiment though. But gasoline blends are not consistent enough from region to region to glean any useful data. Whereas camp fuel is very consistent everywhere. As for using auto fuel in stoves, the lower the octane rating the better. Lower octane fuels contain fewer additives and with burn cleaner in a stove with a bit more punch. Mike
Wow, so much choice and variability! In this poor country I can choose any fuel that I like, provided it is 95 octane unleaded, no ethanol, and no seasonal or regional variability that I am aware of. All 5 gas station brands get their fuel from the same refinery in a single pipeline. Actually, some gas stations also offer 98 octane at an exaggerated price. Yonadav
yonadav, Please contact Optimus and get their 2-cents http://www.optimusstoves.com/seen/technical-support/customer-service/ This can be argued and discussed, deliberated, debilitated, mix in some opinion and what do you have?? Contact the experts and get the straight scoop. They may tell you that low octane non-ethanol is OK in your region. They have egg heads that get paid to answer questions like this. Let us know what they said. Till then, I'm done. AR
Hi AR, I will gladly ask Optimus. However, my question is not "what fuel to use in my stove", but rather "what stove to use with my fuel". I have many stoves but only one fuel. When speaking of gasoline, I have one type that is reasonably priced (car fuel at $2.20 per liter) and one type that is terribly expensive (white gas at $10 per liter). No other options, period. Yonadav
I read somewhere, so take this a pinch of sodium chloride, that the tank rustproofing coating had to be changed for Colemans to resist the extra icky stuff in pump gas. With your fuel prices I would pick a few user stoves and lanterns, buy lots of generators and burn the cheap stuff! How does decent kero compare for cost?
"the tank rustproofing coating had to be changed for Colemans to resist the extra icky stuff in pump gas" - this probably refers to ethanol in the pump gas. There's only one type of kerosene here, and I buy it at around $2.25 per liter, roughly the same as gasoline.
Hi Yonadav, I think your safest bet would be to go for mil.spec. stoves. These were meant to burn 'dirty' gasoline and come with easily changed/cleaned generators. It also looks like the Primus 71/Optimus 80 can go through a lot of car fuel with hardly a problem. Do steer away from steel founts (some of the wartime production of the British Mk2 and Mk3 stoves had a steel fount) unless these have a good coating. Just my 2€cents! Best regards, Wim
Lover vapor pressure equals lower boiling point, which can mean higher tank pressures. I would think that the 8R and 123R stoves and their clones should be able to burn auto fuel with little or no problems, IMO Murph
I doubt this to be the case since the first modern Coleman stoves that were to be used with auto fuel were the "Dual Fuel" models. The manuals for all the other clearly state on the first page that they are to be used only with Coleman fuel or clean white gasoline and that the additives in auto fuel will clog the generators. The M1950 has a "rust resistant" tank. I think they are tinned with something. However I have a couple old ones that are rusted through from the inside. Looked good from the outside, but you could poke a finger through the bottom. I thought a high vapor pressure meant higher volatility and a lower boiling point. Is there a chemist in the house? I do know that my cans of Coleman fuel and gasoline will bulge a bit when it gets hot here but my cans Denatured alcohol don't, and bottles of methanol(Heet)bulge alot. I bought a case of Coleman Premium Fuel in the red plastic bottles on clearance years ago and put them on a shelf in my garage. Went to get a bottle a couple years ago, and they were all empty. Caps still on with foil seals still intact. Scary! Mike
Bummer. How different it could be from the stuff in the can? Premium may just be truth in advertising --- and refer to the normal price. Yonadav, I think you should pick a stove, use unleaded and let us know what happens. I'll chip in two bucks towards a new generator if it clogs.
Itchy, I don't personally think there was one bit of difference. I think it said double filtered or something ridiculous like that. But I won't buy the plastic bottles again, thats for sure. That clearance price turned out to be a bust in the long run didn't it? Could some folks be confusing vapor pressure with flash point? They are nearly opposites. Mike
Seems backwards to me. Lower vapor pressure => higher boiling point. The boiling point is reached when the vapor pressure rises with temperature until it equals tank pressure. Thus, higher vapor pressure means the stuff will boil sooner. Gasoline has higher vapor pressure than water, and therefore boils at lower temp than water. At a given temperature and no pump, as in self pressurizers, vapor pressure = tank pressure. Yonadav
Aw #$%&, you're right Yonadav! Got it bass-ackwards! After 30 years, I really should brush up on my chem and practical physics! Murph
There is perhaps another option for using unleaded without concern for any clogging. Remove the additives. I have done this when re-using isopropyl alcohol to remove contaminants so the principle is the same. You use vacuum distillation. A crude setup can be quite effective and when care is taken completely safe. Using a water venturi to create the vacuum and a hot water coil for heating removes the risk of fire. An ice bath for the condenser and that's about it. Using old pressure cookers as vacuum chambers works remarkably well. Cheers Colin
Ok, I was kicking around the net doing some research and found some very interesting information on auto fuel burning stove designs. Evidently, I was incorrect with the "lots of heat" to burn the crud out. It's actually just the opposite. The object is to heat the fuel just enough to vaporize the lighter hydrocarbons and pass the heavier gunk in atomized, yet still liquid form where they will vaporize OUTSIDE the generator in the flame itself. A very tight and tricky thing to design. If too much heat is applied to the fuel, the heavier components carbonize in the generator and gas tip, clogging it fairly quickly. The problem is exacerbated by the fact that this method apparently on only works with impingement(burner plate roarers) burners. More accurately, I only found references for impingement burners. Can't find any modern references but will continue to look. Sorry for the misinformation, I was confusing some old white gas to kerosene conversions with auto fuel. Does anyone have any good info on this issue? Mike
Ive heated 2 coleman generators till red and both were better afterwards. Both were white spirit/dual fuel ones and no info on what previous owners burnt in them
