2009 Prius Base - $19k

[PaleMelanesian]

There are a couple threads at CleanMPG with all kinds of wild and wacky prius-specific gauges.

[Matt Herring]

Despite the 93 degree temps today the Prius doesn't seem to be running hot. I peaked at 195 degrees tooling around town today with the full upper and 3/5 lower grill block intact. I was doing some reading at priuschat.com and got spooked by some of the posts over there about inverter temps (most seemed to believe 130 was a max temp for the inverter and 220 for the water temp).

Just drove 10 miles around town and SGII reported 64.3 mpg on that route...mostly 35 mph roads.

What a beautiful day outside!

[Matt Herring]

I've been spending alot of time at priuschat.com the past few days and the site is driving me CRAZY!!! 99% of the people on the site post all day long about all the "mods" they are making to their Prius...unfortunately they are mods that pretty up the car. Shiny wheels, fancy interior lights, shiny Toyota Prius stickers, etc. I've been trying to post to as many threads as possible when people are asking actual mpg improvement questions but they are few and far between.

The site is filled with buy it and drive it Prius owners...I guess I shouldn't be surprised though. So far I've come across only 3 guys that report getting over 60 mpg avg tank. I'm going back and forth right now in a thread with a guy that can't understand how I can go back and forth from dead band to EV and back to dead band without engaging the ICE (he asked me if I'm using some type of perpetual motion technique).

Every time I read a thread about how pretty their car looks now that they added new blingy rims to their car I want to ask them why they added weight to their wheels...I can't take it!

[MetroMPG]

Too bad Dan K (krousdb) isn't active.

Because he's both into modding AND was one of the first guys to figure out pulse & glide with the Toyota system. (He was part of the 109 mpg Prius record setting marathon: see Toyota.com : Hybrid Synergy View : 2005 : Fall : Prius Marathoners Top 100 mpg )

[MetroMPG]

You've seen Dan's mods thread, right?

http://ecomodder.com/forum/showthrea...lete-1073.html

[Matt Herring]

I've read Dan's threads but it was good to look at them again to remind myself about the most efficient driving patters...thanks Metro!

[Matt Herring]

So...I'm getting an incredible negative response to neutral P&G over at Priuschat.com

First, I am being scolded for neutral coasting because I am wasting the energy of the regen braking by not allowing the car to coast in drive to recharge the battery. I'm being told I'm stressing the battery by increasing the battery's cycles over time and that I'm actually hurting FE by using EV mode to drive the vehicle at speeds 41 mph or less vs. driving it with the ICE. I agree I'm relying on the battery more than the ICE to power the car during some stretches of my drive but I'm getting better mpg in the process. I've never been below 4 bars on the energy screen and almost every time after my commute to work I'm still in the 5-6 bar range.

Second, I was sent a link warning of over-spinning the engine at speeds 65 mph or greater while in neutral (I read it and it did seem to have some merit). Additionaly, I've been told that I should use neutral only when being towed or pushed and never under normal operation of the car. And I quote...

"There is never any reason to put the car in neutral unless you are being towed, or pulled through a car wash, which is a form of being towed.

There is never any benefit to driving the car in neutral.

However, in neutral THE TRACTION BATTERY WILL NOT CHARGE and this can be very bad, because if you allow it to discharge completely you are in for very expensive service.

The Prius was designed to combine gas and electric drive systems. When you drive in neutral, aside from getting no power to the wheels, AND HAVING NO POWER IF YOU NEED TO MAKE AN EMERGENCY MANEUVER, you are denying the car the ability to operate was it was designed to do.

Please do not ever drive your Prius in neutral. Use neutral only if you need to be towed or pulled or pushed."

What do you all think about this?

[PaleMelanesian]

That kind of attitude, there and at GreenHybrid, is what led to the creation of CleanMPG. I'm being diplomatic when I say they're way off base.

Regen is only about 30% efficient once you consider all the conversion losses going to and from the battery pack. Much better to save the energy on the front side. I really don't see how avoiding charge/discharge cycles will do anything negative to the pack.

The car is programmed to target a mid-level battery charge. As the charge gets to the top, it increases the "desire" for it to assist, and as the charge gets low, it really wants to assist. You'll never be able to drain it fully.

The over-spinning the e-motor is a valid issue. That's why the 41 mph engine-on programming exists. It has a large margin of safety, though. On a sample plug-in Prius that Wayne got to drive, they had raised that limit to the motor's actual 60 mph limit.

[Matt Herring]

Originally Posted by PaleMelanesian

That kind of attitude, there and at GreenHybrid, is what led to the creation of CleanMPG. I'm being diplomatic when I say they're way off base.

Regen is only about 30% efficient once you consider all the conversion losses going to and from the battery pack. Much better to save the energy on the front side. I really don't see how avoiding charge/discharge cycles will do anything negative to the pack.

The car is programmed to target a mid-level battery charge. As the charge gets to the top, it increases the "desire" for it to assist, and as the charge gets low, it really wants to assist. You'll never be able to drain it fully.

The over-spinning the e-motor is a valid issue. That's why the 41 mph engine-on programming exists. It has a large margin of safety, though. On a sample plug-in Prius that Wayne got to drive, they had raised that limit to the motor's actual 60 mph limit.

After I got through all the "pretty up my car" talk on the site and sifted into the actual people that try to maximize mpg's the only real info. I could get was being told to P&G more and use dead band/EV mode less at lower speeds. How does that maximize mpg at all?!?

About the over-spinning the engine...the link I was sent to read about how the Prius engine works is below...over-spinning is addressed in the last paragraph of the section on "Coasting."

Whats Going On As I Drive?

I have a 700 mile trip coming up next week and I was looking forward to finally getting some highway P&G miles under my belt. Now I'm a little afraid to even approach neutral coasting at highway speeds (or at least at 65+...doesn't sound like a good idea at all based on this article...pretty good source...Graham Davies...Prius hypermiling expert).

[PaleMelanesian]

Look up the CleanMPG article on Super Highway Mode for that trip. It's really the best highway technique. P&G in the Prius falls on its face before you get to highway speeds, unfortunately.

Here is the discussion: http://www.cleanmpg.com/forums/showthread.php?t=6179