EV mod for 1.6 mile commute?

In my experience, it depends on a couple of things...
First - grade matters alot. If your run is at all uphill, the battery is depleted much much faster when in EV mode. So, if you have to choose one way or the other for your EV commute, pick the downhill one.
Second - state of battery charge. I am able to drive about two miles every day from the freeway into my parking spot at work in EV mode. But that is because I have a full green-bar battery from about a two mile coast at the end of my freeway run.
For times when the battery is only halfway charged up, the EV mode is used up very quickly.
I have enjoyed my EV switch. I understood from the beginning that I needed to be selective with its use and for the most part let the car decide battery and ICE usage.

 

Let me ask another question: If your commute is only 1.7 miles, why are you driving a gas powered car? A bicycle or walking is ideal over a very short distance like that. Ten miles is harder. You sound like an ideal candidate for an electric vehicle, except the part about going to school probably means no money for such a beast. Maybe an electric bicycle would work.

Tom

 

shtinkypuppie,

Short answer: Maybe, only just maybe. You may see some savings, but I
wouldn't expect them to be significant.

I'm on my second week using the EV Mode switch. It's a mixed blessing.

You may be able to go all the way, one way in EV mode. But then the ICE
will be running constantly on the return trip to recharge the HV battery. So it
might be a net loss.

Following advice from here, the best use for the EV switch in my particular
commuting conditions is for ICE-ON suppression. How so? I use it to cut off
the ICE at stoplights before the warm-up cycle is completed. When I get it
right, I see about a 10% increase in MPG's. But this is only when I
successfully fight the urge to use long EV mode runs. One thing I have
discovered is that if I run the HV batery down below 4 blue bars, the
recharge takes a v-e-r-y l-o-n-g time, and I loose any savings.

If you really want to get a handle on the many tricks to maximize FE/MPGs,
I'd recommend you get a ScanGauge. Yeah, its a bit expensive, but over the
long haul it'll pay for itself. Use the search function to find the many threads
on the significant benefits, not just in fuel savings, that the SG offers.

 

Rokeby's response is good. I agree that maybe you'll make the whole trip (likely one-way only). It's hard to say without knowing your exact conditions. If terrain is flat or downhill, you have absolutely no stops, and traffic is light enough that you can keep speed below 20 or so -- and you start with a reasonably full battery, as Krmcg suggests -- you just might make it. Whoever suggested you might get 5 or ten miles ... no way unless it's all downhill with no stops.

But if you can make it, it just might be worth it. You almost certainly are making it out of S1, but you're likely still in S2. (S1's duration typically is a little over a minute.) As you seem to realize, the car will insist on running to warm itself regardless of driving conditions. It makes sense that if you can make the 1.7 miles, you reduce by one the number of obligatory warmup cycles per day.

On days you don't make the ten-mile school trip, you probably will have a net loss of battery charge. Back-to-back days like this will affect the ability to use EV mode; the car inhibits EV when state of charge is less than 50%.

Engine wear is not an issue; the Prius engine leads an easy life anyway, as much as it's off in normal operations.

As Rokeby suggests, the EV switch typically is best used not to force EV propulsion, but to suppress the ICE when it's not needed for propulsion during warmup. See this for more.

One last thing: One modification that probably will help you is an engine block heater, assuming you have somewhere to plug it in. In your relatively warm climate, I'd wager you could get the car to S3/S4 temperatures (allowing ICE auto-shutdown) even in your short commutes.

EDIT (I see you responded between the time I started this and when I submitted it.): Though few, the stops on your commute may be "deal-breakers." It takes substantially more energy to get the car moving than it does to keep it moving.

 

JimboK,

Thanks for coming up on this thread. My earlier posting had two purposes,
the ulterior one being to induce more experienced EV switch users like you
to fill in the blanks.

Thanks especially for the cite to your very deailed info on EV mode
operation. I need to look at it very carefully to try to get up on the learning
curve. The EV switch sure isn't a magic bullet... for me, any FE/MPG
improvements are way out on the margin.

I got/installed the switch with very limited expectations as to its usefulness.
It's just that its use comes up so often in "hypermileing" discussions that I
just had to see what all the fuss is about. So, now I know.

I also now think that Toyota's not including the EV switch as OEM is not a big
deal. If it were included, it would probably result in mass confusion and
bitter complaints from the average, off-the-street Prius owner.

 

Sounds like a perfect candidate for a Plug-In conversion. You would get 10-12 miles of pure EV range with that mod. You'll be lucky to get over 1 mile w/stock battery.

Hybrad

 

I had a commute of 1.9 miles, and because of lights, it took 10-15 minutes. I used an EBH and my mileage doubled.

I now live 20 miles away, and I still use my EBH.

 

I would try an engine block heater first, before the EV mod. With such a short commute, you should witness a remarkable MPG improvement that you may decide that the EBH is sufficient.

 

Try grill blocking on days of the short drives to further speed warmup?