Prius seldom runs on batteries alone?

I rode in a friend's Prius and he showed me that the engine started up before he hit 5 mph even under mild acceleration. I thought the difference between the "full" hybrids like Prius and "mild" hybrids like the Civic was the ability of the former to operate as a pure electric over a modest range of conditions. It would seem that the Prius' all electric performance is very modest indeed. Is this correct?

Reply to
Gordon McGrew
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I believe that the Prius could theoretically start up and mildly accelerate with the battery powered electric motor alone (assuming it was charged) but there would not be enough horsepower in the electric motor alone to satisfy people (and it might not be safe to accelerate so slowly in high traffic situations). If not accelerating, then the electric motor can sometimes do it alone.

Reply to
Mark A

The electric motor has plenty of juice to run the car. There are a LOT of other factors here...was the heat on? Air Conditioning? lights? Also, the US models are set up differently from the models used in the rest of the world...they run on gas more often in North America. This can be changed by hacking the ECU (and voiding the warranty...)

Also, was the car fully charged? If not, the engine turn on to run the generator, while the electric motor provides the locomotion. The display will show you what's happening...

Reply to
Hachiroku

You can find more expertise at alt.autos.toyota.prius. They will also want to know what year, since there are significant differences between the Classic (2001-2003) and the second generation (2004+). Ours are both Classics (2002), so I'll go from that perspective.

As the others indicate, there are a lot of variables. Cold weather makes it much more prone to run the engine in order to produce heat, which passengers seem to enjoy :-) The state of hybrid battery charge will affect it, too, including the entirely counter-intuitive behavior of restarting the engine periodically to bleed off extra charge if the state of charge is high.

Cold weather, particularly as the temperature drops below freezing, will take the edge off fuel efficiency. I'm barely managing 30 mpg with mainly 3 mile trips in subfreezing weather right now, but when the weather warms up it will go back into the mid-40s. OTOH, what other car would provide 30 mpg under those conditions?

Mostly, the hybrid system knows what to do. There have been reports of misbehavior - especially shuddering when the engine shuts down - that have been corrected by disconnecting the 12 volt "aux" battery for a few minutes. Maybe the car should have ctrl-alt-del keys ;-)

Mike

Reply to
Michael Pardee

I have and drive a Prius. It is just how it is set up. My Prius will start up in electric when the battery is charged enough and accelerate up to maybe 40 or so on electric alone - but it is painstakingly slow. One cannot do this in traffic, thus the need to press down a bit harder and engage the gas engine. I too would very much like for this car to rely on the electric much more than it does now. Tomes

Reply to
Tomes

The point where the petrol engine fires up depends on a mixture of road speed and load being imposed. "Racing starts" are sure to get it going at low speeds, in the Mk2 UK "T4" at least. If just moving away gently from traffic lights (not a common thing in the US has been my impression ), here in the UK I tend to hit 10mph or so before the petrol engine joins the party.

Google for recent (Jan 2007) posts by me under the Subject 'More on Prius "EV" mode'. Being all-electric is not the point of the Prius. Being efficient in its use of fuel is. Huge difference.

Reply to
Andrew Stephenson

Reply to
mark digital©

"Tomes" wrote in news:jWYAh.2397$ snipped-for-privacy@newsread1.news.pas.earthlink.net:

I've heard of Prius people adding another battery pack(in addition to the stock one) and 120VAC charger to get better use on the electric side,and reduce gas usage.Then you can plug it in at night or when you have access to an outlet.

Reply to
Jim Yanik

Yes, except Honda update as another poster noted.

An after-market switch is available to make the current Prius operate entirely on electric motors, like a Euro model. After Andrew's test I thought it would not be worthwhile, but I'm having second thoughts. Steven Scharf (SMS) posted this URL describing how:

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Reply to
Bill Tuthill

ISTR more perspectives on this can be had by browsing around the website priuschat.com -- mostly by folks who wanted to do it and are mentioning odd details. In a UK Euro-Prius, the "EV" button occupies the right-hand position of two switch holes to the left of the steering column. If similar spaces exist in USian models that would seem a good place to put the control. OTOH, a couple of postings mentioned re-using controls on the steering wheel.

Reply to
Andrew Stephenson

Reply to
mark digital©

Thanks for the thoughtful comments. I am really just curious about the state of the technology. Not really interested in purchasing any current hybrid but I would consider it if the right one existed. Electric performance is not an issue in this regard - like I said, I am just curious.

More info on the experience I opened the thread with:

The OAT was about 30F/0C. The engine should have been up to temp at this point. Lights were on and there were three people in the car. I don't know the state of the battery but he generally drives like an old man. Also, the car is a new model, about 2 years old with 7000(!) miles on it. He mostly drives it to the train station and back. He indicated that it almost never ran on electric alone and showed me this by gently accelerating from an electric creep. As best I could tell, the schematic showed power coming from the engine the moment his foot hit the gas.

Reply to
Gordon McGrew

There was a Web site a couple years ago where a guy who is an Electrical Engineer hacked into the ECU via the ODBII connector, changed the mode, and then wrote a program in order to control the ECU from the interior Real Time with a Toshiba Libretto.

Reply to
Hachiroku

Hmmm...I drove a 'classic' for about a week (1999...hey, how'd he do that when the 'first' year was 2000?) and got to where I could control the gas engine with my left foot.

Sad thing was, I got better economy for my type of driving with my '95 Tercel Automatic!

Reply to
Hachiroku

In cold weather get 30mpg ? uh, the corolla will easily do that.

Reply to
RT

I just got a prius and am a bit disappointed that it doesn't spend more time in electric only mode.

My question is for those who have modified the car to spend more time in electric mode: did you get better mileage?

-thanks

-ralph

Reply to
R PRINCETON

The hybrid controller for the Prius is designed to keep the battery between

45% and 75% charged to prolong the life of the battery, so a modification that lets the battery get below 45% charge may shorten the battery pack's life.

Adding additional batteries would theoretically allow the vehicle to spend more time in electric mode but then the engine would have to spend more time running to re-charge the battery.

Reply to
Ray O

Unless the excess of the engine and regenerative braking were underutilized to begin with.

Reply to
mark digital©

Year number applied in the previous calendar year, maybe?

Quite possible. Driving style is so important. Too many folks think a hybrid doesn't benefit from being driven properly. Not true. It's like any other vehicle, that way.

Is the Tercel a small car? The Prius is not. USian Mid-sized, almost. I see Toyota FWDs being advertised, with mpgs horribly lower than the Prius, despite related hybrid tech. (Maybe good for FWDs, though.) Body mass must count for a lot, although of course FWDs have the extra transmission bits to power.

Reply to
Andrew Stephenson

I am betting that the engine/exhaust system was not warmed up yet. It needs to warm up to get the emissions stuff hot, then it goes into its normal mode. This is another of the ways that it is set up by design. Tomes

Reply to
Tomes

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