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Discussion Starter #21
i follow you to increased hp, but when you increse hp, you dont need to push down as hard on the pedal to get the same movement. I have experienced milage gains on my trucks and passanger cars with the instalation of cold air intakes.
 

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Convert that 35C to "F" and that is pretty darn warm. Check out those cold air ducts on your trucks. You just might find a piece of plastic ducting coming from a "muff" surrounding an exhaust header pipe attached to the cold air duct and supplying it with solinoid conrolled heat.
Now, check out under the hood of the Prius and you will see that there is in no way any room there for this type of modification, and none is visable that I could find.
 

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Improved mileage by charging battery

I just got my new 2006, although I have driven several Prius models (2003, 2005).

I notice that the engine runs to warm up when first started but then it also runs after that, even when I'm not accelerating. It seems that its bringing the main battery up to a greater state of charge (I understand that the computer likes to keep the NiMH at 80-20% charge, with 80-40% looking like its preferred range). I also notice the energy display shows less charge in the morning than when I put my Prius in the garage at night.

I also notice that the first 5 minutes of a trip is the worst mileage- 25-30MPG is the best I've done. Get 50-80MPG after that.

I also read about the guys in CA who added a huge Li-Ion battery pack and got nearly 200MPG in 30 to 60 mile daily trips.

So... What if I was able to charge the NiMH battery pack at night. Would I get better mileage (for the first 5 minutes of driving at least).
Has anyone done this? Can you charge the 12V battery thru the power outlet (cigarette lighter) and have the Prius upconvert the 12V to the Main battery pack voltage (seems unlikely)?

John
 

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I doubt you can avoid the warmup during the first 5 minutes of driving, without using an EV switch. Even then, you are just delaying it until later.

Now, if you can get onto a highway under EV and hit 65MPH during your warmup, you might see better MPGs. Good luck on that... :wink:
 

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Re: Improved mileage by charging battery

jharris9 said:
I notice that the engine runs to warm up when first started but then it also runs after that, even when I'm not accelerating.
Are you familiar with warming up stages?
http://priuschat.com/forums/kb.php?mode=article&k=14
It seems that its bringing the main battery up to a greater state of charge (I understand that the computer likes to keep the NiMH at 80-20% charge, with 80-40% looking like its preferred range).
The SOC of NiMH is controlled 40%-80% and preferred 45%-65%.
http://privatenrg.com/#Full_SOC
So... What if I was able to charge the NiMH battery pack at night. Would I get better mileage (for the first 5 minutes of driving at least).
Has anyone done this?
Little benefit with huge expense.
AFAIK, no one did.
Can you charge the 12V battery thru the power outlet (cigarette lighter) and have the Prius upconvert the 12V to the Main battery pack voltage (seems unlikely)?
The cigarette lighter line is disconnected when Prius is OFF.
There is no such upconverter in Prius.

The engine block heater will help you to improve the first 5min mileage.

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Larger circumfrance tires

When replacing the tires if available a 185/75-15 should increase the MPG.

Just simple logic; please explain why it won't work if I am missing something.
 

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Re: Larger circumfrance tires

etyler said:
When replacing the tires if available a 185/75-15 should increase the MPG.

Just simple logic; please explain why it won't work if I am missing something.
What kind of logic are you talking about?

My bet is using a Low-Rolling-Resistance Tires to improve mileage.

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The logic of a larger circumfrance tire, which yes, changes the final overall drive ratio. I have hear of peolpe butting on sporty low profile tires that reduce the circumfrace and their MPG decreases. So why not go the other way in tire size to increase MPG.
 

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etyler said:
The logic of a larger circumfrance tire, which yes, changes the final overall drive ratio. I have hear of peolpe butting on sporty low profile tires that reduce the circumfrace and their MPG decreases. So why not go the other way in tire size to increase MPG.
If the larger circumfrance tires or the higher final overall drive ratio did increase the MPG, please let us know the good logic why Toyota did not do so.

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If the larger circumfrance tires or the higher final overall drive ratio did increase the MPG, please let us know the good logic why Toyota did not do so.
Toyota had to choose between acceleration and MPG. Once the Prius got above 50 MPG (US) that was good enough. Toyota could have choosen a final drive ratio that gave even more MPG but the car would start to become too slow. I am willing to be a bit slower to get a bit more MPG. I just want bragging rights over other Prius owners about personnal MPG.
 

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I don't know about the effect on the drive train, but if you get larger tires, that means fewer rotations per mile. I would assume that the odometer would then record a lower number of miles than you have actually traveled, and a lower speed than you are actually going.
 

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etyler said:
I am willing to be a bit slower to get a bit more MPG. I just want bragging rights over other Prius owners about personnal MPG.
Maybe, that works among a few minority dirvers who are willing to sacrifice the performance, then maybe the MPG number becomes a few percent better.

My suggestion is to understand Prius how it works and to learn the driving technique how to improve MPG number. You'll be able to increase your MPG number 10 to 20 % easily.

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I agree with Ken1784 100%. Once I learned to accelerate slowly, P&G or CC where ever possible, decelerate slowly, and increased my tire pressure my mileage went up dramatically.

When I first purchased my 05 Prius in October I anticipated being very pleased to ave 50+ mpg over the life of the car. I am now at 53.4 mpg lifetime and have hit 59+ mpg twice in a row (2 fillups and 850 miles). I am at 64+ mpg on the mfd for this tank (250 miles) so I should hit 60+ mpg on this one.

I anticipate hitting the mixed driving EPA estimate of 55 mpg sometime this summer, and will be going for more. WHAT A GREAT CAR!!! Many thanks to all for the discussions, tips, and encouragement, even if I have not been noticeable from a posting standpoint.
 
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