...Is the energy savings really enough to justify the extra $180,000 cost? Even at a 15 year lifespan the bus would have to save $12,000 a year in fuel.

Some math...

Assume $3 per gallon, and a 125 gallon fuel tank, let's assume the average MPG for a bus is about 11MPG (very high).

$12,000 fuel per year / $3 per gallon (this number is currently below the national average) = 4,000 gallons per year.

4,000 gallons per year / 125 gallons per fill-up = 32 fill ups.

Allison claims on their site a 60% fuel efficiency improvement with a hybrid. 11MPG + (11 x .6) = 17.6MPG for the very best hybrid bus (this is very, very high...) Estimated range for the typical bus is: 125 x 11 = 1,357 miles per tank, for the hybrid: 125 x 17.6 = 2,200 miles per tank.

For a 4,000 gallon difference, this would equate to 26,976 miles of range to be traveled before that dollar ammount begins to materialize.

For giggles, if the bus was operated 14 hours per day on

**weekdays only** at an average speed of 65 miles per hour, this would take just 6 weeks to accomplish...

So, if you have a fleet of these - and you run them more than 14 hours per day (with different shifts) 7 days per week, there would be significant cost savings - even at lower speeds (where hybrids are most effective) like at an average speed of 16 MPH, it would only take half a year (less than 24 weeks) to start seeing the savings...

With the reality of fuel costs (greater than $4/Gal) and the low average MPG (sub 9 MPG), these hybrids start to look better and better to the budget people

.

Cheers!

-Tim