The Number 42 » Alternate Energy

Break Even Point for Fuel Efficiency Enhancements

Isaac — Wed, 01 Jul 2009 18:12:03 +0000

On my way home from work yesterday I was pondering the question, "if I do modification foo to my car for a cost of bar dollars and it improves my fuel efficiency, then after how many miles is the break even point where that modification becomes cost effective?" OK, I know that is a somewhat random question, but those are the types of questions my brain likes to solve. So, I pulled out a pencil and some paper and after some thought derived the needed equation:

Where:
x = Miles to break even
Uc = Upgrade cost in dollars
E1 = Fuel economy prior to upgrade (miles/gallon)
E2 = Fuel economy after upgrade (miles/gallon)
P = Price of fuel in dollars/gallon

So, for example, lets say that I put $75 into a modification to my car. Prior to the modification I got 18MPG and afterwards I get 20MPG. Let's also say that fuel costs an average of $2.99/gallon. The calculation would be:

Which works out to 4515 miles. So, if my car got 18MPG and I put $75 into a modification that brought the economy up to 20MPG it would take 4515 miles of driving to recover my costs. Anything after that would be saving me money.

There are a lot of scams out there for fuel saving devices. IF you can actually find something that works then you can use the above formula to calculate whether or not it would actually be worth the purchase.

MiniCat car runs on compressed air

Isaac — Thu, 10 Jan 2008 21:56:40 +0000

I bet this will cost an arm and a leg, but I wouldn't mind having one. It would be nice to not have to buy gasoline any more.

Photos: MiniCat car runs on compressed air | ZDNet Photo Gallery

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http://content.zdnet....6-9595_22-182717.html

Z Wheelz

Isaac — Thu, 20 Dec 2007 07:28:20 +0000

I think the idea of some home tinkerer coming up with the latest innovation is very cool. Perhaps it is that "American Dream" in me wanting the little guy to succeed. Last night I received an email from a former coworker. Her husband has started a business designing and ultimately selling electric vehicles. With designs that appear to be modernized forms of a Reliant Robin the company Z Wheelz, LLC has been born.

Right now their web site is sparse, but intriguing. I like the fact that instead of just retro-fitting old cars into electric vehicles that Z Wheelz is actually designing theirs from the ground up. This should make for a lighter weight and more functional vehicle. However, much like the Reliant I would be concerned about safety and stability. The good ol' Robin had a tendency to tip over in strong winds or sharp turns. Having said that, the ZW vehicles look like they have a fairly low center of gravity, so maybe they will end up being OK.

I will be watching their web site closely to see how they progress. Meanwhile, I'd like to know if anyone else knows of similar sites or similar garage tinkerers with the next coolest thing.

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Fuel From Dirty Diapers

Isaac — Fri, 07 Dec 2007 17:40:52 +0000

In this day of rising fuel costs I am totally in to alternate fuel sources. However, this article by ecoble lists some that might be a little too "alternate."

Personally, I really hope that the salt water discovery turns into something viable. It would sure put an end to battling over oil. If this really works then we would have a practically unlimited supply of fuel.

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