New Prius vs Used SUV -- Green Comparison

In those 100,000 miles, the SUV will consume 3660 more gallons of gasoline and pump out lots of CO2. That's only one factor, but an important one.

 

That one is easy.

The Prius.


Just take the SUV out back, put a bullet in its head, then recycle it.

 

I think it's buying a prius assuming you sell you old car. Then your old SUV isn't scrapped but (hopefully) used by someone who needs an SUV (God knows who). It also sends a signal to the car industy that we consumer will recognize and buy superior products.

Now if you would take a fully functiong SUV and scrap it after only 100'000 miles that would be a different calculation and I'm not sure I would say "buy a new car" but I have not seen the RIO costs for such a calculation.

 

Hi Kprospero,

Here is a quickie analysis.

Compare the enviormental costs between the Prius at the end of its life if you buy it now, or the costs of both vehicles (assuming you drive the SUV into the ground, and buy the Prius therefater) at that same mileage.

The thing here is that you are not buying a car, so much as transported miles. So, if you compare both decsions at the end of so many transported miles, the result should be valid.

So, say the Prius lasts 150 K miles, just like the SUV. In 150 K miles of transported miles, you will either have been in the Prius for 150 K miles (Option A ), or in the Prius for 100 K miles, and the SUV for 50 K miles(Option B ). To start, we can look at gas consumption. A gives 3000 gallons of consumption. B gives 4941 gallons of consumption. So, in gasoline alone there is nearly a 2000 gallon advantage. Using gasoline consumption, one work out CO2, NOX and hydrocarbon emissions. The Prius is extremely good compared to all other vehicles in Hydrocarbon emissions.

As far as build effects, A has two options - scrapping the SUV, or selling it to somebody who needs it. Scrapping it wastes 1/3 of the SUV build effect. Selling it wastes none of the enviormental build effect, if the person who buys it, can afford it and upkeeps it for the 50 K miles left in it. B does not waste the SUV build effect, and consumes 2/3 's of the Prius build effect.

Lets assume the SUV and Prius are similar in the build effect - just a guess. The Prius weighs allot less than the SUV, and thus consumes less materials. Your SUV is probably North American assembled from international parts presumably made with resources local to the parts manufacture, there might be less delivery transportation costs with the SUV. The Prius is Japan assembled from Japan parts, made with international resources - the big battery (a little more nickel), and more copper.

If the SUV does find a worthwhile home, option A does not waste any build effect globally, as the person buying it would have just got one from somebody else, if not from you. Scrapping the SUV wastes 1/3 the SUV build effect for you personally, and globally. Comparing Option A scrapping (because its easier) with Option B results in 1/3 build effect units wasted. MIT did a report on building, versus driving energy consumption. I believe it said traditional cars use 75 % of energy consumption in driving. So, 1/3 build effect, relates to 1/3 of 150 K miles at 17 mpg gas costs times 25/75 or 980 gallons of gasoline equivalent energy consumption. Option A scrapping then costs a less energy consumption than Option B by about 961 gallon gasoline equivalent energy (980 ga scrapping waste, versus 1941 savings). Suprizingly, it looks like there is less enviormentally effecting energy consumption when scrapping the SUV, if you buy a Prius and drive it for the next 150K miles.

Enviormental effects aside, one may not be able to afford to scrap out that much money. If it was me, I would be trying to trade-in, or resale third party the SUV as quick as possible, and get into the Prius. If you sell it to a third party who just uses it occaisionally, but will give you at least a trade-in value for it, that would be ideal. We have a van at work, that people use to go to the local hardware store, or take road trips with. But 90 % of the time it sits. Some situation like that would be good. The last van the company had, wore out from chemical effects of sitting, well before its miles were used up.

 

I think the difficulty with answering your question is finding clear numbers on the full environmental effects of building a new car.

Also the SUV market makes a difference: If there is a glut of used SUVs on the market, yours is less likely to remain in service after you sell it, whereas if there's a shortage of used SUVs on the market, someone might buy your used one instead of buying a new one, which would make selling it the clear winner.

It's a complicated question, and probably does not have a simple answer.

In your situation I would base my decision not on the environmental impact of the trade, but on the relative reliability of the vehicles. A new Prius is extremely reliable, whereas a 100,000-mile-old SUV is not. But that was not the question you asked.

 

<div class='quotetop'>QUOTE(KProspero @ May 28 2007, 10:27 AM) [snapback]450970[/snapback]</div>

Actual scientific assessments from Carnegie Mellon and MIT generally assert that a vehicle's largest environmental impact occurs through daily use, rather than in manufacturing.

 

25 years ago a hard drive capable of storing 1 gig of information took the space of 1000 square feet and cost a million dollars. Today, it's $29.99 and you can stick it in a camera. Had people stopped building hard drives and computers 25 years ago cause it was too expensive and environmentally wasteful, then we wouldn't be where we are today.

Buying a newly technologically developing product such as the prius signals to the carmakers that there is a demand for a cleaner and more efficient vehicle. So buying more priuses will funnel more dollars into research of clean car technology. That eventually will make things cleaner AND cheaper. The comparison of your situation in a vacuum might have a legitimate mathematical argument as a math exercise, but in the long run getting the prius pushes the clean technology forward.

 

<div class='quotetop'>QUOTE(KProspero @ May 28 2007, 08:27 AM) [snapback]450970[/snapback]</div>

Actually, that's probably the "greenest" solution for the SUV. In most families, the "green" solution has already been arranged with what they have; typically, the wage earner with the longest commute is taking the highest mileage car to save money. The person with the shorter commute is taking the SUV or truck.

In your case, you're using the SUV only for the trips you need it for, and driving the Prius for daily commuting. That's the ideal situation, even better than selling the SUV to someone else for their commute.

My wife and I have decided we will probably do the same with our Ford Sporttrac, a 17 MPG "sport utility truck" that she now drives 8 miles to work. When we trade up to a better car it could be a better car than the Prius which I will take on my 90 mile RT commute each day. She would drive the Prius for those 16 miles, and the Sporttrac would be delegated to towing our boat and when we go out to the desert.

 

<div class='quotetop'>QUOTE(KProspero @ May 28 2007, 10:27 AM) [snapback]450970[/snapback]</div>

This is similar to a question I posted. I have a van, and the question in mind is what to do with it. The third car is aging, and may have to be retired, but I will likely keep the van. We will log about 5000 miles per year on it, and it is still in very good condition. It is convenient for occasional use. I will probably use the money not spent on another Prius on upgrading a rental house with double pane windows, reducing someone else's carbon consumption (heating the rental).

When the van is retired, I do plan to replace it with a smaller car, probably a Prius (at least that is my vote.)

 

This clipping is from a Toyota Publication titled "Prius Green Report"

The small print in the bottom right corner says that the comparison car is about Prius size, and calcs based on 100,000 Km (about 60k miles).




Staying with one unit defined as 60k miles in a conventional car getting about 27 mpg including manufacturing and disposal, and assuming 60k miles is about 1/3 of a Prius' life, we get

Prius for 60k miles: .1 unit (manufacturing + disposal + maintanence) + .4 units (fuel) = .5 units
SUV for 60k miles: .8 units (petrol only)

If you want to convert the ruler to absolute numbers, I think you can, based on 55 mpg for the Prius, and ~ 19.5 lbs of CO2/gallon of gasoline. This works out to ~ 5600 pounds of CO2 per 0.1 unit = 60kmiles / 55 mpg * 19.5 lbs/gallon / .38 units/60k miles /10

The CO2 breakeven point in kProspero's comparison of a 17 mpg SUV vs say a 51 mpg Prius is about 7000 miles (19.5 * .04 pounds of CO2 saved each mile).


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This is only CO2. Arguments surrounding landfill and toxic metals etc are mute so long as your SUV stays in your garage; and as others have pointed out, delaying the SUV's trip to the grave is the best thing you can do here.