2009 Prius Details

<div class='quotetop'>QUOTE(fan-atic @ Apr 20 2007, 07:32 AM) [snapback]426697[/snapback]</div>

We'll just have to wait and see what Toyota really delivers. There are a lot of rumors on new features, functionality, and specifications.....

Keith

 

One of the great things about diesel engines is that they don't rely on a specific air/fuel ratio. You can have as much air in the combustion chamber as you want, and then you just inject as much fuel as you need. Which is why an idling diesel uses about 1/6th the fuel of a similarly sized idling gasoline engine. So for diesels, you should never NOT turbocharge them. The turbo gives you more power when you stomp on it, and more efficiency from a faster burn when you are gentle.

Gasoline engines are getting closer and closer to diesels with variable timing, direct injection, and even some compression-ignition engines coming along. With this it should be possible to put in more air, without necessarily having to put in more fuel, like you usually have to do.

Cooling it is a valid issue, but an electric supercharger (just another air compression/injection method, usually powered off the engine, instead of from the exhaust gases) is not a bad idea. Getting more oxygen in there can definitely improve efficiency, if you aren't making things too lean to burn right.

I suppose we'll see. The Prius is showing how many of our ideas about how a car 'should' work can be changed, and improved. My hope is that the tradition will continue, until people no longer think of a drive train in the same way they used to.

-Sam

 

Turbocharging is a joke for the Prius. Don't people understand that turbos require PREMIUM gas? Does anybody really believe that premium gas will ever be required on a Prius? Certainly not me!

 

Electric supercharger: Use electric motor to turn fan to blow air into engine to cause pistons to push harder to turn engine harder to turn generator faster to make more electricity to power motor to turn the wheels.

Option 2: Use electric motor to turn wheels more.

Hmmm....

Nate

 

<div class='quotetop'>QUOTE(ml194152 @ Apr 26 2007, 10:21 AM) [snapback]430660[/snapback]</div>

You are probably right that turbocharging will require premium gas. But don't think that's a bad option: What if it improves your gas mileage from say 50 MPG to 60 MPG (a 20% improvement).... would you consider premium gas then?

 

<div class='quotetop'>QUOTE(Tideland Prius @ Apr 20 2007, 12:49 PM) [snapback]426846[/snapback]</div>

May have already been mentioned here, but Edmund's believes the Prius will stay at 1.5L

11011011

 

To answer the original question, turbocharging by its very nature only works when power demand is high. A wider throttle opening produces more power which produces more exhaust gas to spin the turbo to force in more air to produce still more power...reverse that by shutting the throttle plate and the turbo spins back down. What that does is give you a small engine with the power capacity of a much larger one. Efficiency at low load remains relatiely high compared to that V6 of V8 that would have been stuffed in the engine bay instead.

I can't think of many reasons to use a turbocharger on a Prius powerplant unless Toyota wanted to reduce the displacement of the engine. The premium fuel requirement typical of turbocharged engines might be alleviated if they really go nuts with the atkinsonization, reducing the effective mechanical compression ratio through valve timing. I'm pretty sure that's the Miller Cycle: atkinson plus turbocharging. Who knows?

I'm not expecting anything really revolutionary for '09, although a piece of me still hopes for something huge. Anything to improve highway fuel economy would be a major plus, and that probably has more to do with the transaxle than the ICE.

 

<div class='quotetop'>QUOTE(ml194152 @ Apr 26 2007, 02:21 PM) [snapback]430660[/snapback]</div>

Where does it say you need premium gas for a turbocharger? I have a Dodge Ram 2500, with turbo and runs only on Diesel fuel. The power comes from the exhaust gases. just my 2 cents. Take Care.

 

<div class='quotetop'>QUOTE(Zimri @ Apr 27 2007, 06:56 AM) [snapback]431071[/snapback]</div>

Diesel is a completely different animal. Turbochargers heat up the intake air through compression, increasing cylinder temperatures. The that extra heat can cause the air/gasoline mixture to ignite before it's supposed to, reducing performance and possibly causing engine damage. Premium fuel has a higher octane rating, meaning that it is more resistant to detonation and will allow for more boost/better performance. And that is why it is required on pretty much every turbocharged gas engine made today. Some, like my girlfriend's Volvo, only require 89 octane though 91 is preferred. (That engine is a "light pressure turbo" which peaks at ~7 to 8psi vs. 14psi and up on some performance cars.)

 

<div class='quotetop'>QUOTE(John in LB @ Apr 26 2007, 03:08 PM) [snapback]430698[/snapback]</div>

Nope. I have owned cars that required premium and mid-grade (89 octane) gas. Never again!

It would take a miraculous increase in MPG, much more than 20%, to get me to consider premium.

 

We have heard from Toyota that the 2009 will have a 1.8 liter and Li batteries.

The car may have a low pressure turbo or someone quite new....

A Turbogenerator - kinda like half of a turbocharger with a generator to make power for the hybrid system from the exhaust. Some would say that this is a waste due to engine backpressure but it does net more power then the backpressure it causes. The exhaust actually leaves the car at a lower tempeture due to the energy extracted by the turbogenerator.

 

<div class='quotetop'>QUOTE(Dan. @ Apr 26 2007, 03:30 PM) [snapback]430707[/snapback]</div>

Yes, but Toyota says they are going to use the 1.8L corolla engine. A shame since I think a diesel would be a better option.

 

For those interested in a new drawing of the 2009 Prius, check the March 2008 Motortrend. This drawing shows a very sleek 2009 Prius, based on information and rumors from Toyota employees, although many drawings are a bit exaggerated. Also states that the engine will be 1.8 litres, and initially will have the current battery pack. Mileage is supposed to be better. Hope the price is not raised. Lm2

 

Anyone happen to have a scan of the Motortrend photo? I'm not into turbocharged engines but it wouldn't prevent me from buying.

I'll be happy with seat height adjusters.