EV SWITCH

Thanks, Daniel, that really helped.

Since delaying engine warmup is bad, the EV switch does not have the practical application I hoped and it would be in the realm of toys. I guess I am just destined to be one of those people who only get 43 mpg in their Prii. At least until after my warranty expires, the technology matures, and thus I do the plugin conversion, which would work wonders in exactly my situation.

That's fine. I have a feeling my old Mitsubishi Galant got about 10 mpg in the same segment on its way its overall mpg about 20.

One final question - I believe you when you say delaying warmup is bad, you did say "do not" three times in bold, after all , but why is it?

 

It wouldn't work for my commute either (18 miles each way). First is residential, but the ICE needs to be warmed up. By then it's freeway, followed by a gradual climb. There's a sharp drop and then another climb. Going home is the reverse. The EV mode won't help there.

 

The last part sounds right, but you have alot of the same issues I do.. my work commute is about 13 miles... about half way there my mileage starts getting good... but I never drive long enough on those commutes to really get good average mileage... the last part has to average with the first crummy part and so the average is only about 42mpg... on the open road I "like to the beach" I get about 50. I suppose if I did more city driving it could be more yet. this is with 35 to 45 degree temps.

I use my EV more in the eve when I get in my rural areas before I get home.
I tried to use it in the morning, but I have found if the engine is cold "although you can engage it, if done immediately upon startup", the EV will only let you go about 20mph and then it seems to stall. If you push the pedal yet furthur the ICe kicks in.

See the system again protects the cold battery! It actually feels like you hit a wall.. plenty of power till you hit about 20.. then its like the computer says "no more".
I would think if it was just a cold battery that it would be more gradual without such an instant "wall".

But when the battery is warm, you really have more high end power "20 - 34mph"

 

Jef: Actually, I think the EV switch would help in your situation, just not using it the way you suggested.

The reason it is bad to run a long distance in EV is because it is inefficient. You have all the conversion and charge/recharge losses. It is a WASTE to run the battery down by driving the Prius as though it were an EV for a mile or two (the most you'd get under the best of conditions) and then having to completely re-charge the battery.

What I'd advise you to do if you put in an EV switch, is allow the engine to start and run until it's warm enough for EV to engage. This will be a LOT sooner than when the car begins to go electric on its own. Once it is warm enough, then you use the EV switch the same way the car normally uses electric mode:

When the SOC is low, allow the engine to run.

When the SOC is high, use the engine to accelerate from a stop, and then use EV to maintain your steady speed until the next stop. Then disengage the EV so the engine can accelerate from the next stop. Etc. Unfortunately, the maximum speed in EV mode is 34 mph. (The highest speed you'll normally see electric mode when the car initiates it is 42 mph.) So if your street speed is over 34 mph you cannot use EV mode in any case.

What I'm trying to get people to see (and there are some here who just don't get it) is that you use EV mode the same way the car itself uses electric mode. And recognize that the Prius is not an electric car and was not designed to be and does not work well as an electric car. It is a hybrid and was designed to use the engine and the motors together, shutting off the engine for brief periods when the engine is not needed. (When the battery is well charged and the demand for power is small: the engine is inefficient at low power output, whereas the electric system is inefficient at high power output.)

But in any case, the difference in mpg will probably be small. The bigger difference is in how you drive and what your driving conditions are. DaveinOlyWA has the EV switch and John1701a does not, but both get very high mpg. I'm only getting around 45 mpg (though I'm hoping for better when the weather warms up, now that I have longer trips... in Fargo, my normal trip was 10 minutes.) If you really want to improve your mileage, you'd be better off visiting one of the mileage gurus like Dave and studying from him. (I suspect Dave is actually a Zen master.)

On the other hand, Consumers Union got 45 mpg overall, so you and I aren't doing all that bad.

 

Well there is alot of descrepency and misunderstandings and disagreements about this subject......

Three basic issues I see:
1. Gas savings techniques?
2. Battery life tips?
3. Does it affect Warranty?

I stumbled upon an older thread where some key veterans defend the issue that batteries are safe from harm using EV as long as you don't go hogwild crazy about it.

It sounds like opinions, comments, and recommendations will vary based on which of those points your really asking about. They get mixed and blended so much in discussion, its hard to tell whos talking about what.

Here is an excellent discussion where Evan shares his thoughts:
http://priuschat.com/index.php?showtopic=1...l=warranty&st=0