Hybrid car pollution and fuel use may be reduced up to 42% compared to similar gas powered cars. The average pollution reduction for 29 current hybrids shown on the list below is however about 23%. The average fuel reduction is 21%.
So, in the short term hybrid reductions in pollutants and fuel are beneficial.
In the long term though, hybrids will continue to pollute and use large amounts of fuel. As the chart below shows for example hybrid sales or increased driving miles only need to increase by an average of 23% to
offset all CO2 savings.
Hybrid Car Pollution CO2:
Manufacturers provide CO2 as well as other pollutant data for their vehicles. The CO2 data is usually in the format of grams per kilometer. The Toyota website for example, lists the new Prius as producing "as low as" 89 g/km
of CO2. These results are based on UK testing using the Imperial gallon.
This comes out to 19.3 pounds of CO2 per US gallon of gasoline burned.
The US EPA uses 19.4 pounds per gallon based on a few different assumptions. Using these figures, you have to do the math to get an idea
of just how much the Prius pollutes per year for example. We use
20 pounds CO2 / gallon gas for quick math.
The Quick Math:
Multiply your vehicle Gallons of gas used x 20 = pounds of CO2 per gallon.
Gallons x 20 = pounds CO2.
Hybrid vehicle gallons of gas can be estimated from the charts here, here, here or from the EPA. Just take the miles you drive and divide it by the fuel economy of that vehicle.
Or, the US EPA lists carbon output as Tons per Year. The Prius is listed as making 3.7 Tons of CO2 annually. This is based on driving 15,000 miles and
a 55% city / 45% highway split on the fuel use.
To visualize just how much 20 pounds of CO2 gas is, check here.
Hybrid Car Pollution by Tons
Hybrid Car Pollution by Percent
Hybrids could save millions of barrels
of oil per year: enough in time?
Another big consideration is resource use, mainly crude oil and gasoline. As it is shown on the hybrid car statistics page, the current hybrid fleet can reduce gasoline use by around 8,500,000 barrels per year. That is about 1 days use by the USA.
While any decrease in resource use is better than an increase at this time, the decrease is not significant to global oil supply over a long time. For example, the world consumes somewhere around 85,000,000 barrels of crude per day. This rate of use is only rising,
but is very likely nearing a peak, and possible decline soon.
Peak oil is still decried by some as a panic paradigm. However, as time goes on, more and more important mainstream scientists and policy makers are adopting the notion of an ocean of oil depletion. These same people are also working on strategies to deal with the decline.
One of the main ways to mitigate oil depletion electrify transport, as has been recommended by some well informed people, and recently backed by the likes of Sir Robert Branson. For starters, he owns an airline, and is very interested in fuel availability. Kuwait of all places has recently completed a mathematical analysis of Middle East fields (among others) and reached similar conclusions. They see peak oil in 2014.
Bottom line: reducing CO2 output by 36% or so is good, but still leaves in a lot of carbon in the atmosphere. This carbon will continue to build up over time, especially as more and more cars come onto the road.
At some point, you need to take the next step of all electric vehicles. That and walking or biking are the only ways to reach zero emissions at this time.
