Cali shifting to 15% ethanol in gas

[Chops]

Winter blend has a higher butane content. Butane has a boiling point of 31.1 F. At low temps it will stay dissolved in gasoline, kind of like C02 in a soda can in your fridge, but spray the gasoline into an intake port or directly into the cylinder and the butane instantly becomes a gas. This higher vapor pressure ensures trouble free cold starts.

Butane is cheaper than the other primary alkanes in gasoline; pentane, hexane, heptane and octane. Using more butane saves money in the manufacturing process, but it doesn’t work well in high temps. Kind of like a soda at 90 degrees, all of the CO2 will gas off, leaving the soda flat.

The next part not directed at you, but all of the commenters talking about the pros and cons of ethanol. The ethanol is added as an oxidizer. Gasoline never completely and cleanly combusts into C02 and water. Oxygenating gasoline leads to more complete combustion, with less unburnt hydrocarbons and less carbon monoxide.

Because of SoCal’s unique geography, with a low lying basin abutting a continuous wall of 6,000-10,000 ft mountains and relatively gentle onshore breezes that aren’t strong enough to push the urban air pollution out, SoCal has the worst air pollution in the US.

So they needed to take action to clean up their air. In the 70’s they started using MTBE as an oxygenate, but it has its own raft of problems related to its toxicity, industrial pollution and ground water contamination.

In the early 2000’s, the era of MBTE wound down and ethanol was the next logical choice for reducing air pollution.

Whether it’s the right choice to force everyone in the US to use it, is a whole different topic.

But for SoCal, it 100% makes sense.

And since 2/3 of California’s population lives in SoCal, it made more sense to implement it state wide, rather than having regional gasoline rules.

So even if it takes 40,000 BTU input energy to make a gallon of ethanol, that only contains 76,000 BTU of energy, it is still worth the cost/effort of using ethanol in high air pollution areas.

Thanks for your insights! I started reading this thread maybe 95% ignorant about ethanol. But now a much improved 75% ignorant thanks to posts like yours and a couple others too.

I was not around during 1955 when the LA smog reduced visibility to zero - but did drive the length of the LA basin several times during the 1970s. It is amazing how the air quality has improved there since then.

Sponsored

 

[Bret Grabber]

This car needs a Sox & Martin paint job

And a Hemi!