Thursday, January 03, 2008

Very important MPG fact to consider...

First things first... this is a very simple concept but the idea to put it into a spreadsheet to illustrate it is NOT my idea. I can't seem to find the original website in the Digg-iverse but I think it is a very important point to make.

If you're reading about the same stuff I am (which I can imagine that you are), you are seeing a lot of stuff about 100, 200, even 300 mpg vehicles being imagined and conceptualized (and built). Personally, I love the idea of extreme ingenuity and material science being applied to sustainable transportation but this kind of research begs the question 'are triple digit MPG cars essential?"

It is quite easy to believe that fuel efficiency has a linear relationship with fuel used but that is not the case. If it were, there would be a point that we would reach where a car is so efficient it begins producing fuel. This can't happen so the relationship is not linear.

When you plug the numbers into a spreadsheet, you see this kind of data:

When you plot MPG (x-axis [bottom]) versus amount of fuel used on a graph, it looks like this:

When you see fuel usage like this, what do you think? Did you understand this concept before now? What implications does it have? Study the numbers and I think you'll see some interesting things...

My salient points:

1) Buying a slightly more efficient SUV makes a BIG difference. If you decided against the 6.2L Chevy Tahoe (12 MPG city) and went with the 5.3L version instead, you'd save almost 180 gallons of fuel and $580. If I wanted to save that by buying a new car to replace what I have, I would have to get 35 MPG (like a Camry Hybrid) or five times the increase in gas mileage.

2) Big changes in the low end of things makes a huge difference. If I opted for the Tahoe Hybrid over the aforementioned 6.2L option, I would save 536 gallons of gas at about $1,700 a year.

3) My friend who bought a Camry Hybrid to replace his Ford Explorer (getting 9 MPG [had to be one part poor Ford MPG, one part lunatic driving style, and one part mechanical problem of some sort]) is saving 1,200 gallons of gas per year and almost $4,000. That's over $300 per month or a significant portion of his car payment, I imagine.

4) If you drive an SUV, remember that every little MPG helps. If your EPA MPG rating is 14 but you drive more aggressively than others, you're probably getting more like 11 or 12 and costing yourself over $700 per year to drive like that.

5) Buying an Element is going to cost me an extra $185 per year (57 gallons of gas). Reaching my 30 MPG goal while keeping the car is going to save me $356 (110 gallons of gas). *sigh*

Honda! Make it damn hybrid already, will ya?!?!

Honda Element SC

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