Rising Fuel Prices

[Drifter]

E85 has never penciled out when I've looked at it in the past, but as another forum member pointed out things have changed lately. E85 is currently ~40% cheaper than E10

E85 btu: 81,860 (28.5% lower than pure gasoline)
E10 btu: 110,660 (3.4% lower than pure gasoline)
Gasoline btu: 114,500



I wouldn't count on that trend holding long term, but it kind of makes me want a plug-in hybrid flex fuel vehicle for maximum flexibility in times of volatility...

[redpoint5]

I wonder just how good a vehicle designed to run only on E85 could be considering it has an octane rating of over 100?

Heck, are there even NOx considerations with that little petrol? Maybe direct injection and heat ignition become possible at that point.

[cRiPpLe_rOoStEr]

Originally Posted by redpoint5

I wonder just how good a vehicle designed to run only on E85 could be considering it has an octane rating of over 100?

There were dedicated-ethanol cars in Brazil, yet they weren't so extremely tuned to take the most benefit from ethanol.

Heck, are there even NOx considerations with that little petrol? Maybe direct injection and heat ignition become possible at that point.

NOx and PM have increased on spark-ignition engines precisely due to direct injection becoming more widespread.

[redpoint5]

Originally Posted by cRiPpLe_rOoStEr

There were dedicated-ethanol cars in Brazil, yet they weren't so extremely tuned to take the most benefit from ethanol.

NOx and PM have increased on spark-ignition engines precisely due to direct injection becoming more widespread.

My point being, I wonder what efficiency is possible if a major automotive manufacturer went all in on E85. 110 octane is quite good if an engine is tuned for it.

Does ethanol produce NOx like petrol? I'm not familiar with the mechanism that causes it in the first place. Most of air is nitrogen and oxygen. Is it simply heat?

[serialk11r]

Originally Posted by redpoint5

Does ethanol produce NOx like petrol? I'm not familiar with the mechanism that causes it in the first place. Most of air is nitrogen and oxygen. Is it simply heat?

Yes, nitrogen + oxygen + high temperature. Any air breathing engine produces NOx.

With US refineries running at 95% capacity, if a refinery goes down over the summer, we might get $10/gal in CA...so I try to top up the fuel tanks. E85 is usually uneconomical to run in CA but right now it's cheaper per BTU than gasoline plus it's an octane booster so I am adding a bit to each tank if I drive by the Propel Fuels pump.

[rmay635703]

There are about a dozen refineries sitting mothballed

Even one sitting in northern Wisconsin

No effort to repair any of them

[cRiPpLe_rOoStEr]

Originally Posted by redpoint5

My point being, I wonder what efficiency is possible if a major automotive manufacturer went all in on E85. 110 octane is quite good if an engine is tuned for it.

The main issue would be cold-starting with some winter blend such as E70, or even to provide a limp-home mode with gasoline. Brazilian dedicated-ethanol cars and early flexfuels had an auxiliary cold-start gasoline reservoir under the hood for instance, so going one step further in order to at least level the game when it comes to MPG in a dedicated-ethanol engine would be harder. I'm sure direct injection would make it easier, despite the NOx issue. At least it could be easier to overcome the NOx issue in a dedicated-ethanol than in a Diesel, using water injection instead of DEF.

[serialk11r]

Originally Posted by rmay635703

There are about a dozen refineries sitting mothballed

Even one sitting in northern Wisconsin

No effort to repair any of them

It's seen as a poor investment because over the long term, gasoline usage is projected to decrease with electric car adoption.

Originally Posted by cRiPpLe_rOoStEr

I'm sure direct injection would make it easier, despite the NOx issue. At least it could be easier to overcome the NOx issue in a dedicated-ethanol than in a Diesel, using water injection instead of DEF.

The combustion temperature of ethanol in air is very close to that of gasoline in air. If you vaporize the ethanol completely and then put it in a high compression ratio engine made to take advantage of the cooling effect, you'll have even higher temperatures than gasoline since the higher heating value is greater per unit oxygen consumed.

The only way to meet current emission standards is exhaust aftertreatment. I wouldn't be surprised if natural gas stoves in homes produced more NOx per unit heat than cars are allowed

[JSH]

Originally Posted by serialk11r

It's seen as a poor investment because over the long term, gasoline usage is projected to decrease with electric car adoption.

rmay doesn't want to hear the truth.

[RustyLugNut]

Originally Posted by redpoint5

My point being, I wonder what efficiency is possible if a major automotive manufacturer went all in on E85. 110 octane is quite good if an engine is tuned for it.

Does ethanol produce NOx like petrol? I'm not familiar with the mechanism that causes it in the first place. Most of air is nitrogen and oxygen. Is it simply heat?

Some of these heavily modified Hondas and Mitsubishis, etc. run 10 second quarters using E85 and do so meeting the strict emission checks here in the AQMD (Air Quality Management District) of the Los Angeles Basin. E85 allows them to run higher boost.

Just as long as they run the factory Exhaust Gas Recirculation (EGR) or the equivalent, they can easily meet the strict local regulations. EGR keeps the flame front below 2300 C where NOx formation becomes significant. The high inherent oxygen content of E85 keeps the unburned HC, CO and particulates (in direct injection models) to a level below that of gasoline.