Biopower Opportunity?

The main points to remember about using E85 are as follows:

– It’s cleaner. Less damage in terms of emissions and the bad stuff released is supposedly absorbed by the trees in the growing process.

– It allows for more fun. A higher octane level means more bang for the buck.

– It’ll make your car thirstier. Fuel consumption suffers.

My lifelong everlasting friends over at Consumer Reports have just done some E85 testing. Autoblog Green have a brief blurb on it here. In addition to ABG’s story, Kraig from New Hampshire has emailed me his summation of the report:

The October 2006 issue of Consumer Reports just arrived at my house and contained an article on E85 titled “The Ethanol Myth”. Using a Chevrolet Tahoe (Full size SUV with a 5.3 liter V8), they found that using E85 exacts a 27% fuel economy penalty versus regular gasoline, effectively raising the cost per mile in fuel by almost a third. In acceleration tests, they found that the E85 blend provided quicker acceleration to speed than did gasoline, but by only a small margin. [0-30 mph — 3.4 sec vs. 3.5; 0-60 mph–8.9 sec vs. 9.1; quarter mile in 16.8 sec at 84.6 mph vs. 16.9 sec at 84.5 mph]

The article does mention things already mentioned on your site including the relative inefficiency of corn-based ethanol (prevalent in the US) and the promise of newer technologies such as cellulosic ethanol production. CR’s take is that this technology is still developing and that no one solution will solve all of the US’s or the world’s energy needs as we try to reduce dependence on fossil fuels. Their warning to consumers is that E85 is not inexpensive to use in terms of cost of fuel or gas mileage, but it is less expensive than the higher purchase cost of a hybrid.

I’ve just popped over and had a look at Saab’s Biopower press release info to take a look at a few things and if the car were on the market, I’d suggest that Saab could have an opportunity here to show people how Biopower,when properly set up on a sensible vehicle, can live up to some of the promised benefits. More than a Tahoe can, at least.

Firstly, there’s no arguing about the fuel consumption. Saab’s own press material claims a reduction in the city cycle in the order of around 30%.

Consumer Reports managed to measure significant reductions in emissions with the Tahoe, a claim that Saab also make and one that’s to be expected. It’s the central selling point of the fuel (though one could argue that the more popular current issue of oil independance has overshadowed it temporarily)

The performance figures are where the real difference lies. CR measured a negligible power boost in the Tahoe:

the E85 blend provided quicker acceleration to speed than did gasoline, but by only a small margin. [0-30 mph — 3.4 sec vs. 3.5; 0-60 mph–8.9 sec vs. 9.1; quarter mile in 16.8 sec at 84.6 mph vs. 16.9 sec at 84.5 mph]

Whereas Saab claim a much bigger differential with the 2.0t Biopower 9-5:

Running on E85, the Saab 9-5 2.0t BioPower engine delivers 180 bhp and 280 Nm of torque, compared to 150 bhp and 240 Nm when using gasoline, a significant 20 per cent increase in maximum power and 16 per cent more torque. This gives even sportier performance. In the 9-5 Sedan, zero to 100 kph dash can be accomplished in 8.5 secs and 80-120 kph in fifth gear in 12.6 secs, compared to 9.8 and 14.9 secs when running only on gasoline.

Now, my question is: Is this significant difference in relative peformance between the Tahoe and the Saab just because CR did their speed tests in a big-ass Chevy Tahoe, which is going to be as slow as a wet week anyway? Or is it becuase turbocharging is the best way to take full advantage of the higher octane rating in the E85? If so, then maybe Saab has another opportunity to show some people how it’s done.

If they could somehow tweak the tuning to close the MPG gap then more’s the better. That one’s purely theoretical, but maybe there’s something in that performance issue to be sold.

You may also like


  1. The Saab Trionic is one of the best engine management systems in the world.
    It allows to gain the extra performance with the more compressable E85.
    The Tahoe with the big bulky engine is surely not optimized so efficiently as the less than half size Saab engine.
    The most important advantage of the bioethanol that growing the plants used to make the ethanol will absorb the similar amount of CO2 what the car will emit by burning the ethanol.
    It’s recycling.
    The other is (of course, it needs lot of time) to become more independent from those damned oil countries which can rule the world by controlling the price of oil.
    However, currently the production of E85 is not cheaper than producing the regular petrol. It can be more popular only if the goverments will support it with tax allowance, etc.
    Getting more popular it will increase the amount of manufacturing and allows more cost-effective production.
    It’s very important to set the price under the normal petrol prices.
    In Hungary the government gave a tax allowance that makes tha E85 about 30% less expensive than the regular petrol. If the car is 30% more thirsty than the regular cars the owner of the “green” car has no any advantage except the higher performance. Actually, it’s a doubtful advantage, because you have to pay more tax for the higher performance car. 🙁
    So, our goverment did it just for a show… 🙁

  2. Getting a vehicle like the Tahoe to go from 0 to 60 mph in 8.9 seconds — and still achieve even 15 mpg — is an engineering achievement.

    GM has some very good engineers. It the top brass and marketing types that have them working on the wrong types of cars.

    In theory, I believe you could design a very high compression, all-ethanol engine that would take advantage of ethanol’s high octane rating. But it would not be a flex-fuel vehicle – it would have to be all-ethanol, all-the-time. Which, given the scarcity of E85 pumps, is a non-starter.

    The only way to use both regular gas and E85, and still take advantage of E85’s high octane rating, is a turbo.

    (Saab’s variable compression engine would also do this, but that’s another story)

  3. Swade and Greg have it right: the engine setup is the key and turbocharging helps.

    I’ve been a critic of E85 right from the start — I believe that it simply moves the energy consumption up the supply chain rather than create real change. It does have advantages from a renewable energy perspective, which is something I suppose, but you’re still burning hydrocarbons in an inherently inefficient IC engine. E85 is just a lateral shift to me.

    Greg’s got a great point with the ethanol vs. flex fuel technology. In Brazil, you buy cars that either run on gasoline or ethanol. The government subsidizes ethanol, so that’s the choice that most make. Here, you need fuel flexibility which is a technical challenge. It can be (has been?) done, but it ain’t easy, as the 27% fuel efficiency hit demonstrates.

    I’m still waiting for the step change in either battery or fuel cell technology. That’s where the real change occurs IMHO.

  4. eggsngrits,

    Saab BioPower is definitely a flex-fuel engine, it can run with petrol OR E85.
    Technically, it’s not a big challenge, only need to change the fuel delivery line due to the more corrosive ethanol, and change valves and valve seats to higher temperature-endurance.
    Burning the ethanol gives 25-30% less energy than burning regular petrol. There are no wonders, to get the same power you need to burn more.

  5. Ivan:

    I understand the technology. I understand that E85 isn’t as potent.

    What I’m saying is that an engine set up for E85 only will be more efficient than a flex fuel engine. Period. And either way, internal combustion thermal efficiency is horrible.

    Again, just another reason that I think that E85 doesn’t match the hype.

  6. eggsngrits,

    Ok. But it makes no sense to develop engines to run only with E85 or E100 at the moment. There are too few stations worldwide where you can buy the fuel.
    You are right, the efficiency is not good, just like in any internal combustion engine.
    The car engines based on solely hydrogen cells or batteries are far from the everyday use with the same comfort, performance and reliability.
    The E85 is a step forward to the more enviromental friendly cars. It’s definitely not the perfect solution, but it’s ready to use.
    The Saab Hybrid COncept is the next step. Maybe a few years after they can introduce a new invention.

  7. I’ve just got some “insider” information.
    A regular car converted to E85 has an average 30% extra fuel consumption in normal climate. In cold weather and short distances it could be even 50%!
    The 20-30% only extra consumption of Saab BioPower is the result of the very smart Trionic engine management, it could not be achived with more simple regular engine managements.
    However, I heard about that the fuel pump is still the weak point of the current 9-5 BioPower cars.

Leave a Reply

Your email address will not be published. Required fields are marked *