PureSpeed1 said:
What is a bladder? :shock:
And, is it true that you will get better gas mileage when the engine is fully broken in?? If so, how many miles for the engine to be broken in and how much more gas will i save?
The fuel tank in the Prius is like a balloon inside a metal protective housing. When the gas is drawn into the engine, the bladder contracts, leaving no place for vapors to form. The metal housing protects the bladder from outside damage which might occur in a fender bender or worse.
Race cars use bladders extensively because they dramatically reduce the potential for explosions in collisions becuase there is no place for vapors to form and it's the mix of fuel and air that causes the explosions. The reason most passenger cars do not have bladders is that they are more expensive to install.
Another environmental plus for bladders: with no place for vapors to form, there is no vaporous emission from your gas tank when you are refueling the car.
Because it is a flexible membrane, it will be somewhat stiff when new and you will not be able to put anywhere near 12 gallons of fuel into the car until the bladder gets broken in which takes several thousand miles.
So....when you get to the last square on your fuel gauge, you will be surprised when the tank will only accept about 7 gallons of gas. Everyone keeps asking where the other 5 gallons are.
There is some speculation that Toyota intentionally calibrated the guage to read empty when there was still at least 3 gallons of gas; this was done to prevent people from driving the car out of fuel and attempting to run extended distances on the electric motor. That's not a good idea because the engine and motor are combined and the electric motor needs the gas engine to keep the battery charged.
You asked about mileage increasing when the engine is broken in. My experience is that temperature has more of an effect on the mileage than the engine being broken in or not broken in. The electric motor/battery combo works better in warmer weather, so you will notice an increasing mileage as the summer opens up. By fall, however, your mileage will drop slightly. Your Prius' gas bladder will eventually accomodate quite a bit more gasoline and your mileage will increase through the spring and summer, so that by July, you should max out at the highest mileage/distance per tankful you'll get unless you alter your driving techniques or routes. Lots of us learn to drive by the mileage, and you'll be amazed at how drastically different your mileage will be going to the same destination, but by different routes.
The ICE (internal combustion engine) in the Prius runs at a near constant rpm, which is why it is so efficient and why it should last a very long time. The stress of starting up from a stop is handled by the electric motor and the CVT transmission rather than by cylinder compression in the gas engine. The gas engine doesn't require a breaking in period as older cars did; Toyota's only caveat is to avoid sudden acceleration/deceleration as much as possible, but this is to protect other systems like brakes as much as to save the engine.
Hope that answers your questions.
Good luck, have fun.....you can't help having fun driving this thing.
Bob
