Re: 100 miles to the gallon car

[perseus]

Re: 100 miles to the gallon car

by perseus » Fri Mar 05, 2010 3:28 am

perseus

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I believe 100 miles to the gallon is possible.

Think about a few facts.

The internal combustion engine has increased in efficiency only fractionally.

When you look at cubic feet per minute of air fuel mixture the results are disappointing.

One third of the energy produced in the power stroke is lost to the compression stroke.

Another third is lost in the exhaust stroke.

Therefore only one third of the energy produced in the power stroke is directed to the wheels to move the car.

http://www.protect-new-idea.com

terrycan123 have you examined the area under each part of the PV diagram for this? The amount of pumping and compression work is defined by this and has being a central focus of engine designers for a century.

After all the heat losses a modern efficient engine at full load might have potentially 50-60% of the energy left which has to be multiplied by the mechanical efficiency which takes these compression & expansion losses into account

The mechanical efficiency can be quite high at low speed above 90% in some cases, however this drops of considerably at light loads and high speeds were most of the energy is lost in practice.

http://www.antonineeducation.co.uk/phys ... /Fig42.jpg

PS I cannot highlight or paste images in the same way as in other forums! Something is not right is this because editing features are restricted on early posts?

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[Hayseed]

Re: 100 miles to the gallon car

by Hayseed » Sun Apr 11, 2010 8:17 pm

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What about, what they call superchargers? Something that you hook to a fan belt and it pushes air into the engine, and boosts the horsepower phenomenally. Can horsewpower be transferred to more miles per hour or with the supercharger you just burn more fuel?

I have a cousin who it is said developed an engine that runs on Compressed Air, and the patent was bought up from him by the government, since then others have tried to infringe on this patent. Anyone else have a cousin like this.

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[Michelle]

Re: 100 miles to the gallon car

by Michelle » Sun Apr 11, 2010 8:37 pm

Michelle

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PS I cannot highlight or paste images in the same way as in other forums! Something is not right is this because editing features are restricted on early posts?

Hi Perseus:

Yes, as a relative newcomer, you do not yet have ability to post images. We had a really rough time with some spammers posting very indecent images on our site constantly so we turned it off for new posters.

As you get more involved in the site, you will soon have the ability to include images I think.

Welcome to the site!

Michelle

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[JoeWaisman]

Re: 100 miles to the gallon car

by JoeWaisman » Sun Apr 11, 2010 9:07 pm

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What about, what they call superchargers? Something that you hook to a fan belt and it pushes air into the engine, and boosts the horsepower phenomenally. Can horsewpower be transferred to more miles per hour or with the supercharger you just burn more fuel?

In general increasing horsepower reduces the MPG efficiency of a vehicle. This occurs because most of the available horsepower is rarely used on the street. The sport tuned engine might be most efficient at 5000 RPM, but under normal driving circumstances it would only operate in the 1500-3000 range.

Superchargers, larger intake ports, ram air and multiple intake ports can make the intake stroke more efficient. This actually means that your engine is taking in more air AND gas per revolution. The smaller engine can then put out as much power as a larger one...which is good because the larger engines have more inertial mass, and resistance - due to larger contact area of moving parts.

For MPG improvement it does make sense to downsize the engine and then do everything possible to make it breath well. One exception is cams...sport cams accomplish this at the cost of rough lower RPM operation. The rest could in theory improve fuel efficiency. Unfortunately they are generally coupled with performance engines rather than fuel efficient ones.

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[apapage]

Re: 100 miles to the gallon car

by apapage » Mon Apr 12, 2010 8:06 am

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The way to maximize mpg is to limit the amount of energy wasted. This is the main reason that hybrid cars achieve better MPG. For example, hybrids use braking to recapture energy that would otherwise be lost as heat. A more promising hybrid seems to be hydraulic.

http://www.greentechgazette.com/index.p ... r-x-prize/

Driving style plays a big role as well. I recall seeing a video on youtube where a UK group tested the prius against the bmw m3 series for mpg going all out on a test track. The prius returned 17 mpg (spirited driving) while the bmw got 19 (relaxed driving).

http://www.youtube.com/watch?v=dKTOyiKLARk

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[Scrupulous]

Re: 100 miles to the gallon car

by Scrupulous » Mon Apr 12, 2010 12:22 pm

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That hydraulic car sounds pretty interesting, Antonio.

There's also been talk about boiling fuel into pressurized vapor, to really boost the combustion efficiency and MPG at any speed. I wouldn't doubt that's what some tinkerers are already doing...

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