Prius as a taxi?

Astoria... yes I do not like that parts of the city you never know where you can turn ..left/right or at all then all those stop sign ...

The tracking battery is not that big (not likely bad ) TWO conditions will kill your MPG 1. HARD acceleration either quickly depleting your battery and then engine can not keep up. 2. actually overusing the battery for moving about in the 30-40PMH area battery will not last enough and you have efficiency issues at re-charge ... this hybrid car shines on "recovering" some energy at breaking and supporting glides (very low power requirement where ICE is bad)

So in my opinion P&G is not very effective in the city but "anticipation" of the traffic could be VERY effective start breaking early !!! let off the gas early etc... and if/when you have something to monitor a little more the HSI it can do wonder ...

I use the driving under load technique monitoring instant MPG and RPM ... but I do not have much experience with "heavy" vehicle I drive almost always alone ...

Hope this help ...

And on top of that ICE stops when you are stopped so if you do not need either A/C or heat you save on idle a LOT

If you get the full SG ... yes it can read battery current/voltage/temp you name it ... could be very useful​

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If you own an android phone you can consider a cheaper solution ... BT EBDII ELM327 device with Tourque I love it .. just do not have the data plan to take full advantage .... ​

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As I said it improved my driving a lot and gained about 3-5 MPG (after driving a prius genII for two year and gen3 another two...) when I pay attention.... more you drive more it will worth for you ... always wanted to drive a cab in NYC but it will not pay my bill Ia m afraid .. but would do it as a second/part time job​

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If you can do it yourself or at LEAST see when it is done so you are not cheated this could give you several MPGs extra especially in the colder month ... with a lot of stop and go...

 

Just take a drive out of the city into the suburbs and see what kind of mileage you get. Reset your trip meter when you get there and just drive around for a while mixing both local and highway roads. Take the city/taxi variable out of the equation and see if your mileage improves.

Just a thought!

 

I'd also be curious what accessories you're running in the car. I used to have a 5 watt 2 way radio, taxi meter, sat nav and dispatch computer all running. If I left the car out of Ready mode, the above items would give the 12v a real battering. That's why I'd always leave the car in Ready between jobs as it would always keep peak power and be continually charging the 12v. The Prius doesn't charge up the 12v as quickly as a car with an alternator, so if you're leaving the car switched off BUT leaving 2 way radios and computers running, then you'll be running the 12v down quickly but not topping it up fast enough later. After a few months of this your 12v could be starting to feel the strain. The previous cars you had would have had much bigger 12v's with good alternators.

I guess it depends how many accessories you have running and how much you leave them running with the car switched off. But might be a reason for the lower mpg's - your car is spending all its time trying to top up the 12v.

 

Thought,
Your suggestion of the new Prius v might make a lot of sense for you--especially if you do a lot of airport travel with folks who have a lot of luggage. I have to say my 2010 Prius is not real good when it comes to multiple large pieces of luggage behind the back seat.

 

come on now with this topping up .... 12V battery mystery ...the main battery WILL charge the 12V battery quite some time but that doesn't make any difference (unless the battery already failing because than it complete waste)

Just let me show you why even if you would say it keeps it the higher voltage 14.6V ... while you in Ready but PARK the current is less than 5A (I think specs says 4.3A ).... so 14.6x4.3A is 62Watt NOW your low beam lights EACH 55W ..... so constantly charging the battery would have just about the same effect than ONE lightbulb... So night time driving would have noticeable mpg hit .... Never heard about that if that is happening.

I maybe wrong

 

I mean if this guy is stopping for 30 mins between jobs and switching the car off BUT leaving his meter, radio, computer and extra roof lights ON then this will drain the 12v significantly. Do this 5 or 10 times a day and it will cause problems.

To use your analogy, it's like leaving the headlights on for 30 mins without the car powered up. Once or twice it won't cause a problem, but 5 times a day every day it would.

Does that make it clearer?

 

I do understand the problem occurring to the 12V battery due to extensive discharge cycle. And yes if car is not in Ready mode leaving your headlights on will discharge the battery rather quickly

What I am disputing that, this has any significant MPG hit ... due to recharging the battery (even constantly) ... so keeping up with the analogy running with low-beam headlights on (I do not have the running light which would be better since that is lowered voltage high-beam ) 110W with the tail and other lights which comes up about ~150W would have significant MPG hit ... I did not hear this from anyone but charging the 12V is keep coming up...

So you are right, in theory, every load is hurting MPG but not measurably. So a mostly dead battery takes approx 65W (both the current and the voltage is controlled by a DC-DC converter).

 

Am I missing something here? Driving with the headlights on doesn't affect the car much as it is designed to run like this. Also, driving with taxi lights on the roof sign, a 2 way radio, meter and dispatch computer don't affect it when in Ready mode and driving BUT when the 12v has been discharged the car has to charge it back up again thus causing the mpg hit. The same happens with a failing 12v where the car is continually trying to top it up which causes the hit. Does anyone have stats or figures of this? Surely the car trying to top up a 50% drained 12v all the time on a taxi will cause an mpg hit? By the time it is nearly topped off the car is stopped again causing the accessories to start draining the 12v again.

It not that the car can't handle the load when running, but rather that it is continually charging up the 12v AND powering the accessories and other items such as the a/c. There are reports that people who have installed sound systems with big amps have had problems with the Prius running them.

 

Remembering how the Cab drivers approached lights in NYC. RACE TO RED LIGHT TO BE THERE FIRST. OFF AGAIN TO BEAT THE OTHER DRIVERS TO THE NEXT RED LIGHT. This is not conducive to economical driving with the Prius or any other car. Let the other guy race to the light, you try to time the light, if possible. You will get there just as fast. Post a note to Grumpy Cabbie in England and see what kind of mileage he gets. He also has many interesting post.

 

I am not sure if you try on purpose misrepresent what I am saying ... OF COURSE every electrical load will have affect on MPG the question is how much ...

Let me try it again when you have your headlights on you add ~150W (110 the two light bulbs another 40W for taillight licenscplate whatever) it is estimated LESS than 1mpg (on average) so my argument is that even a dead battery or properly working which needs to be recharged is 1/2 of the load so I do not have any idea about your taxi specific load I bet it is less than another 150W.

In theory best to use them from the motor generator, next best traction battery worst 12V battery and then recharge (that battery) max 30% efficiency loss.

Please stop saying that a battery which needs to be recharged will have big effect not really more than if you have the car in Ready while using the electronic stuff. (worth case scenario 30% efficiency loss) so

I just gave you the number approx 65W is wasted when battery doesn't hold any charge (or when it needs to be recharged)... that is probably not measurable in MPG terms !!

The A/C is a LOT bigger load... especillay on full power when interior is hot ... and WE know that the 12V battery is charged by a specific current so it is NOT an infinite sink ...

sound system trouble, maybe (must be very big sound system) ... because, yes there is an absolute max limit on the 12V bus somewhere around 200A combined but current at that level even the body resistance is noticable :-(


(check prius as a UPS/generator thread very thorough analysis what current/power can be safely taken

 

Are you saying there is no possible link between off-Ready loads and the kinds of problems mentioned in this thread?: Weird stuff happening? MPGs dropping? Test The Battery

 

The link is that off-Ready use (unless it is careful) will result overly discharged 12V battery and long term degraded battery .. and that will bring those "weird" stuff

Weird stuff WILL happen (intermittent issues at first) but noone there can conclusively show MPG drop... actually several post says after putting in NEW 12V battery mpg did not improve ...

There is NO reason why MPG would suffer any more then running lights ... yes a dying battery puts some load on the 12V bus BUT NOT significant to be measurable as MPG loss .

The weird things are happening because the degradation happens slowly ... and you may have a no start event in a colder morning when you drove the car for a short time the day before ... (weekend ) and the temperature MATTERS a lot. Also how much charge is in the battery so yes you may not have enough juice to boot the car !!! then next day or for weeks this scenario doesn't happen at all ...

And again this weird stuff will COINCIDE with colder weather which effect MPG in a big way especially if user doesn't understand how to handle it.

So far NOONE had any explanation why a bad battery alone would result 10MPG drop or even 5

 

It also could be the extra weight your car carries. I get around ~60 MPG when I am travelling alone (my current weight is 190). When I am traveling with my wife and son I only average around ~50 MPG. Even when I am driving the same road that I travel to work and using the same driving technique (pulse and glide). My wife's current weight is 116 pounds and my son's weight is 60 pounds. By adding 176 extra pounds I drop around 10 MPG.

I understand that mathematically I would only drop around 1MPG per 100 pounds. The issue is that I have to turn on the air conditioner when my wife and son are with me. On top of that I limit my hypermilling to pulse and glide.

The funny part is that I was reading an article on this exact topic a couple of days. Here is a link to ithttp://aluminumintransportation.org/downloads/AluminumNow/Ricardo%20Study_with%20cover.pdf.

 

^^ I have very strong doubts that a 5% increase in total vehicle weight causes a 20% increase in fuel consumption. It is far more likely that the family presence alters your hypermiling style, consciously or otherwise.

 

I completely agree with you. Should have explained further by what I meant.

 

I know exactly what you mean! When my wife is in the car my MPGs drop also, due to A/C and altered driving techniques. Although they don't drop as drastically as yours does. She is getting used to it by now. The one trick I do use when I put the A/C on is that I only set it a few degrees below the ambient temperature if it's not scorching outside.

As long as they see that the A/C button is lit and it's comfortable they are good to go and you will save MPGs.

 

Those probably the main reasons you see low MPG in city.

First of all put in ECO mode in city.

2nd look ahead and anticipate (too many drivers accelerate just to slam brakes on next traffic light). When brake make sure pedal doesn't go beyond max regenerative on indicator.

with respect to HVAC you get better results if you set higher temp (I usually set up 2deg below external) and run fan in recirculation mode.