Most efficient mode for long trips?

The jury is still out on that topic.

The recharge mode does consume more fuel. Does it consume more than it's worth? I am not sure, yet.

It is going to take drivers continuing to experiment, to find the answer to that question.

 

For day trips, save EV for when you can use it (non-highway driving) and HV for the rest.

For long road trips, like my 1,711 miles last weekend with no opportunity to plug in, take advantage of charge-mode while cruising at high-speed.

 

From my experience and from what I've read, charge mode is good for going down steep declines. It will charge faster that HV mode. For me, I use EV then switch to HV when I'm at cruising speed for warm up, then back to EV til depleted then HV. Charge mode will charge the EV portion of the battery but HV mode won't. What's great about the Prime over previous Prii, is you can use the HV portion of the battery at highway speeds, unlike the 43 mph limit on older hybrids.

 

ev auto. let the computers do the work for you. i don't know if this will use up all your ev, but i think so.

 

I just took a 72 mile trip (each way). Going up the hill on the way out (about a 2000 foot net climb) on mostly 75 highway, I got 68mpg using about 10 miles of EV range. I used Ev from my house down the big hill which is about the first 10 miles or so. I switched to Hv for the long climb up to the highest point on the trip and back to Ev at the top. I used Ev for a long slight descent to my destination of about 10 miles.

I'll use the same method on the way back - Ev for light load sections, Hv for heavy loads. Let you know how I do.

EDIT: Didn't go all the way home, but with about 15-17 miles of Ev range used, I averaged 74.6mpg for 120.3 miles with no net altitude change. Ignoring the Ev range, that works out to about 63mpg which is pretty good for mostly 75mph highway.

 

This thread really interests me as I just got my Prime over the weekend. Trying to figure out how to maximize my mpg. So you don't just blow through your EV battery from the start and wait for the hybrid system to take over?

 

I drive about 45 miles each way. No charging coming home. Mostly highway speeds varies from 55-70 depending on the spot. Terrain is mostly flat with only slight rise/falls in elevation.

 

I got my prime premium in November and have almost 10k miles. My most common drive is 105 miles mostly on a 4-lane state highway with occasional lights. I put the car in EV mode at lights and uphill and usually arrive with about 2-5 miles of EV left.
I would love to trust EV auto to do it for me, but it doesn't know how far I'm going.

Posted via the PriusChat mobile app.

 

For my 18 mile one way trip to work, I am on EV until I get to the freeway on-ramp. I then stay in EV until I reach about 55 MPH then swap to HV for the next 12 miles.

I swap to HV after I get up to speed (55-65 MPH) in order to reduce the instantaneous stress on the ICE as soon as I swap from EV to HV. Swapping to HV (cold engine) while in the middle of accelerating to merge onto the freeway would qualify as "stress" in my book. I am making the assumption that once my speed has stabilized (i.e. I'm in the HOV lane at 55 MPH+), the ICE doesn't have to work anywhere as hard as it does when accelerating to freeway speeds.

I want to have HV on for one continuous stretch in order to fully warm the ICE up. After it's warmed up, I swap to EV when speeds get below 40 MPH or so. Efficiency in EV for speeds above 45 MPH seems to be very poor. That's why I swap to HV for those speeds.

 

First, I don't see why you wouldn't be Ev for the entire 18 miles.

Second, putting it in Hv doesn't stress the engine because it essentially stays in all Ev propulsion until the ICE is out of warm up. It even does this if you have no Ev range left, dipping into the hybrid portion of the battery charge.

 

At the time of the morning when I'm driving up the freeway, I can be doing 70+ MPH. EV mode at that speed seems to be extremely inefficient to me.

Didn't know about the warm up period, though. That explains why the engine indicator on the energy screen doesn't light up immediately.

 

Not necessarily. Just tonight driving home on the freeway, I decided to let the EV charge go to Zero and not put it in HV on my own. Was going 65-68. ICE hasn't been on in at least a few days, EV charge depleted about 3 miles from where I exit the freeway. As soon as the EV range hit 0.0, I could feel the ICE go on -- it did not stay in EV range pulling from the hybrid buffer of the battery. The green EV MODE light immediately went off and the ICE came on right away. About a minute later, it started going back and forth between short EV and GAS spurts (like normal HV driving) but the first thing that happened when my EV ranged ticked down to 0.0 was the ICE immediately came on, and the MFD showed the ICE powering the engine and recharging the battery. Then shortly afterwards it started doing its normal HV mode driving (EV, Gas, EV, Gas, EV, Gas, etc) but the gas came on first. Though the ICE hasn't been on for a couple days, today was a warm day (though this was around 8pm), maybe it's different in colder or different weather...

 

That is a misunderstanding of how warm-up takes place.

With an aftermarket gauge, you'll see that RPM of the engine is held back by using HV capacity. The battery is used as a buffer to keep emissions lower until waste heat for cleansing is available.

Once warm-up is complete, that HV capacity is restored by the engine running to recharge as part of the usual hybrid operation.

 

"About a minute later...". During that minute, the car was pulling most or all of its propulsion from the hybrid portion of the battery charge and the ICE was in a warm-up cycle - exactly as I said, and exactly as my car does.

 

Maybe it does that eventually, but not right away.

The other day I switched to Hv at Ev=0 and then climbed a very large hill. Ev still provided all my propulsion and when I got to the top, the engine started working. I drove another 8 miles without it noticeably refilling the Hv portion of the battery and when I got to my destination and plugged in, it said "5 Hours and 50 minutes to full charge" rather than the usual 5:10-5:30.

 

This morning when I was heading out to work, I kept a close eye on the energy diagram when I switched from EV to HV on the freeway.

The engine icon did not light up yellow (assuming that the icon turns yellow to indicate the engine is actually ON) but was dark. The energy flow indicators consisted of red arrows going FROM the engine icon TO the drive motors and batteries. Usually the energy flow indicator arrows are yellow or green (may be incorrect about this).

So am I to assume that since the engine indicator was not lit up, the red arrows indicated the engine was in some kind of warm up mode? If so, why were there no energy flow indicators from the batteries to the drive motors to show that the traction battery was being used to support propulsion during the warm up period?

After an unknown period of time (couldn't eyeball the energy diagram while trying to merge onto the HOV lane - if you've driven the 405 you'll know what I'm talking about!), the engine indicator turned yellow and the energy flow arrows appeared the proper colors and were going in the appropriate directions.

BTW, my ICE had not been used since the previous Friday (3 days on pure EV mode) so it was stone cold. Morning temps were probably around the mid 60's.

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* Correction - When heading home today, I did see that the battery was powering the drive motors when I swapped from EV to HV. There were also power indicators (i.e. arrows) coming from the ICE but the ICE icon was not lit up. After X amount of time, the ICE icon did turn yellow, though.