Generator Fuel Question

Skibane wrote:
Gasoline quality is a consideration.

Ethanol in gasoline reduces its energy content, and thus the generator's power output. Generator manufacturers test and rate their products using ethanol-free gas, so this power reduction isn't reflected in their specifications.

The upshot is that a generator with marginal power output using ethanol-free gas will have even more marginal output using gas with ethanol in it.

The maximum amount of ethanol allowed in gasoline was recently increased to 15 percent - so this is going to be more of an issue than it previously was.

Since ethanol tends to shorten the storage life of gasoline, many folks avoid using it in generators. Unfortunately, in areas where ethanol-free gas is available, it usually costs quite a bit more. That extra expense needs to be included when comparing fuel costs.

If the mfg designed the engine to run on 10% ethanol AND adjusted the carb correctly you won't see a decrease in power output. You WILL see a increase in fuel consumption (about 3%). In fact properly designed an engine running on alcohol can have more power than gasoline, just higher fuel consumption. Don't confuse energy content/gallon with power output, they are two completely seperate issues.


your statement on 15% ethanol is misleading.
1) yes 15% is allowed but ONLY if 10% pumps are also available
2) In many locations it is ONLY allowed during parts of the year
3) We've been traveling all over the west/midwest and south and have yet to see a pump with 15% ethanol

IMHO there is more FUD in the 10% ethanol that actual issues. Yes, 25+ year old gas engines can have problems with 10% ethanol, but modern engines it is seldom an issue even if carb's are left full for extended periods of time. In the last 20 years I've very seldom drained a tank on a small engine including my honda generators with 10% ethanol even when it was going to sit likely for 6 months and never had an issue.

What I have found is that many of the small engines on yard equipment that doesn't have a fuel bowl and float what one thinks is a fuel problem is just those el cheapo carbs hitting end of life. When a brand new OEM carb is $10-$15 there can't be much in them. When I've replaced them I found the throttle shaft was wobling all over and letting air/fuel leak. fuel bulb not working etc.