After Gutenberg

My compliments, ABG, the Syngas Spin fits nicely with the Saab Bio-Power Ballyhoo.

Soon after Autoblog Green showed a graph that emphasized cellulosic vaporware cellulosic ethanol as the best choice for an alternative fuel, Art Vatsky passes along some alternative fuel spin from Csaba Csere of Car and Driver magazine.

SAAB systems markets their “BioPower” cars outside the U.S. and are soon to bring them to the U.S. ABG commentator notes that “these are ‘flex-fuel‘ cars which can run on any blend of gasoline and ethanol up to E85. So you run on E85 when you can and get that power bonus (through SAAB’s turbocharging expertise), but when you can’t find E85 you run on regular gasoline.”

As previously noted, advanced ignition timing, a higher compression ratio, and a higher turbo boost pressure, all increase engine performance and efficiency.

SAAB systems also has developed an engine optimized to run on E100. Gripen notes that you can run it on regular gasoline, but you will see a diminishing power output.

This is because this car has had its compression ratio changed to optimize for ethanol. It puts out double the horsepower than its gasoline counterpart (150 bhp per liter!). 300 bhp out of a 2.0 liter turbocharged inline-4 cylinder engine.

As previously noted, other modifications include variable inlet and exhaust cam phasing for optimum air flow, more durable valves and valve seats, and bioethanol-compatible materials for the fuel system. The Virginia Tech team used a similar, 2.0-liter E85 flex-fuel engine in a split-parallel hybrid with 67 kW motor with a 288V NiMH battery pack to win Year Two of the Challenge X competition.

A different, yet related strategy is what SAAB calls “rightsizing”.

You “rightsize” your engine. Most cars don’t need 300 bhp. So that means you can make a smaller, lighter, less polluting, more efficient engine with less displacement (saving money if your gov’t taxes based on engine displacement) without having to sacrifice horsepower or torque by using ethanol.

As Rafael Seidl noted, turbocharging and direct injection, plus cam phasing, are great improvements, but you only save fuel if you also decrease displacement “and apply some long gearing in the tranny” (a.k.a., transmission).

Beside mentioning Saab development of small, powerful, flex-fuel engines, Vatsky works in the topic of ethanol injection. Ethanol suppresses detonation because of its high octane number (about 104 or so); and, direct injection of ethanol results in a lot of evaporation that cools the charge and prevents knock. As previously noted, Ethanol Boosting Systems hopes to have on the market within five years a direct ethanol injection system that can be added to cars.

I will wait to see the numbers before I sign on to that one. Still, this will hopefully spread use of E85 beyond the 1,000 or so stations that carry it in the US. By using improved performance to attract buyers, this is a smart way to reduce dependence on petroleum without sacrificing the performance we like to know our vehicles are capable of.

One the negative side, there needs to be two tanks for fuel and, I surmise, two fuel systems so there is no lag when the fuel is switched. Run out of E85 and your run out of high performance, just like on the single tank Saab system.

On the positive side, most of the components would not be expensive and are of known technology. There would be savings in weight and in efficiency both on gasoline and on E85.

Gripen actually suggests switching the emphasis, i.e., use ethanol as the primary fuel and inject gasoline or some similar combustible fuel when better starting is needed. The disadvantage to such a suggestion is the lower energy value of ethanol. Also, there would be a need for the alcohol fuel to be cheaper than the gasoline. The advantage is in the emissions profile. He concludes rhetorically, “Isn’t the point to lower gasoline usage as much as possible?”

In seeking environmental, economical and technological solutions, DME fares better than biodiesel as an alternate fuel, not as well as gasification or cellulosic ethanol, according to one consultant’s report, which also indicated that electric remains the best choice.

Of course, yours truly had to add some ethanol insight. And, ABG commentator GreyFlcn advocated standard TDI Turbo Charged Diesel that provides better mileage, lower cost, and lower CO₂ emissions. (The subtext is missing in these claims, e.g., better (highway) mileage, lower (fuel) cost and lower CO₂ emissions (with suitable after treatment).

He may be referring to a recent VW push to promote the efficiency of, and refinements to, their existing technology and an announcement of efforts to develop a 200+ mpg concept car.

GreyFlcn also noted that either butanol or ETBE (a.k.a., DME) is better, more practical choice than ethanol. Previous data would seem to indicated that gasification of biomass to DME (a.k.a., dimethyl ether) compares unfavorably when compared with other alternative fuels. Still China is investigating coal to dimethyl ether, to include direct synthesis of DME from Syngas.