Sugar in the gas tank


On the home page of CT, Tom+Ray deal with Marisia, who had somebody (ex suspected) dump sugar in the gas tank. The advice T+R gave her was “Generally speaking, it’s harmless, because the sugar doesn’t mix with the gas.” (Or words to that effect.)

What I’m wondering is if E10 gas has made this advice obsolete.

The shortest possible explanation of the Organic Chemistry behind this: Molecules are either “polar” (i.e. water) or “non-polar” (i.e. oil). “Like dissolves like” means that polar stuff (like sugar) dissolves in other polar stuff (like water). Since the hydrocarbons in gasoline are non-polar, they make a poor solvent for sugar.

But ethanol is an odd duck, O.C-wise. One end has a carbon saturated with hydrogen, just like oil (the “non-polar” end); the other end has an O-H (which is polar, as it is in H2O.) This “dual nature” of ethanol is what makes it soluble in both petroleum and water.

Wouldn’t this dual nature of ethanol allow a damaging amount of sugar into the (E 10) gasoline?


EEK! Please move to “the show” [hangs head in shame…]


You may have missed the right area to post your message, but your organic chemistry is correct.


Eventually, that sugar will make it to the fuel pick up in the tank that either has a screen or the actual fuel filter. The undissolved sugar granules are going to plug something up.


Interesting thought. I’m not sure that any studies have been done to that effect (and by studies I mean “no jackasses have poured sugar into an ethanol-containing tank and then written about it anywhere” :wink: ). I’m not ultra-strong in chemistry, so you’d probably know a lot better what the resulting ethanol/sugar solution’s physical properties would be. If it’s fluid enough to get through the injectors and into the combustion chamber, I wouldn’t think all that much would happen because the normal combustion cycle would just burn the ethanol/sugar and send it out with the exhaust. If, however, it makes the ethanol overly viscous, you’d end up plugging things up.

The only thing I can think of is that when you dissolve sugar in regular alcohol (as in, say, a mojito), you don’t end up with a sticky solution, even after complicating it with lime juice, so perhaps still nothing would happen.


The sugar will not desolve but instead will clog up the strainer, pump, filter and/or injectors.


I have actually myself overhauled a 1973 VW Bus with the type IV engine in it (it was in 1982) and someone put something in the fuel that caused the piston rings to seize on the pistons. The agent might not have been sugar but someones knows a product that will damage the engine internaly when introduced through the fuel system.

I actualy got burned on this repair as the owner came and took the car after I completed the work while I was at the bar next door to my shop. I was on shakey ground in the area of a mechanics lein (even though I had a signed repair order) as CA had not issued my Bureau of Automotive Repair certificate until one day after I wrote the repair order.

Perhaps the owner deserved to get the engine “sugared”