Comparison of EV Usage at Different Times

use it on the 10% non freeway and the rest does not matter.

 

Most of my trips have a suburb start & end with highway in the middle. I use as much EV as available up front, switch to HV, then use whatever EV is left when I leave the highway. That tends to work out nice.

On the highway in EV-BOOST mode (traveling faster than 62 mph with lots more electricity than ordinary HV) with whatever surplus you may have is nice too. The results segments with +100 MPG are an obvious plus. But that's not the best use of limited battery since cruising is so efficient anyway. Also, you tend to do somewhat better saving engine warm-up for the more steady driving.

 

Time of day matters too. I would use EV in the early morning when temps are below 60F and fuel efficiency would be less than later in the day when temps are much higher.

 

I would use EV to insure that the ICE warmup has you going fast and never stopped at a light.

Mike

 

that's interesting mike, i have been warming up at a lite before getting on the highway. do you think i should ev up to 55mph and hit the hv then?

 

Sitting still with the engine running isn't an efficient choice, since the load is so low. It's better to fire up the engine (hard pedal or toggle the HV/EV button) as you are approaching the ramp prior to accelerating.

 

Drop the pedal to the floor some time. I was surprised to discover the "protect" mode had somewhat of an override. The engine still won't redline, which in itself is rather low at 5500 RPM. Instead, it shoots past the 1500 RPM ceiling and you end up getting around 2750 RPM. I hadn't expected that to cause jump to 76 mph with a cold engine. The speed limit is only 70 mph on that ramp just 3 blocks from my house. It goes to show you how well thought out the design really is... and how infrequently you actually need maximum acceleration.

As for shortening your EV range, it won't happen if you're driving beyond a short distance. The system is designed to restore that used during warm-up by taking advantage of the efficiency the power-split-device offers. Remember, heat is required for maximum emission cleansing. That extra engine load while warming up ends up being a win-win situation.

 

I have been experimenting with running in EV as far as I can before I get to an estimate of 10EV miles. Not surprisingly, that generally takes me about 7 actual miles in the morning because of the east-west downhill from home until I reach the north-south coastal junction. At that point I switch over to HV and leave it on for most of the rest of the freeway trip. Since my one-way is 30.1 miles, the altitude drop over that drive is from about 600ft to sea level. The best one-way mileage I've had so far (86.3 mpge) is by using this protocol.

I can confirm that the engine speed at warm up (1544RPM) is sufficient to keep the car at freeway speed. I've never had to floor it before reaching 130℉, so I haven't seen RPM go much over 2700 during warm up.

I've tried running in EV until it's exhausted. That ends up actually being lower mileage (78.4mpge) because there is about a 4.4 mile stretch between the freeway and work that's ideally suited to EV mode (40mph, level ground). While the first third of the trip generally results in quite high mileage (as in 130/140mpge), the portion that remains after that tends to be far more pedestrian (in the 50/60 mpge range). As a result, the overall trip mpge suffers.

Running the DRCC showed initial promise, but I found myself too often wasting regen possibilities on the freeway. The coastal mesas provide numerous opportunities for downhill runs of about a mile. Coasting in EV generates quite a few miles along the way.

So now it's try to stay in EV until I hit the first uphill freeway junction onramp (unless I'm forced above 62mph, anyway) and then try to maximize HV mileage until I get off the freeway. This has the added benefit of leaving me with about 7 miles of estimated EV range for the drive home. That trip, as can be inferred, is all uphill, so I've never had a great result on that trip. I think 62.2 mpge is about the best I've ever done on that trip. That result is highly variable because the traffic flow is generally much heavier on the trip home. Depending on when I leave work, it can be anything from full speed ahead to 5-10 miles of nothing but stop and go traffic. Where the trip to work is pretty predictable at 35 minutes, the drive home can be anywhere from 40 minutes to sometimes more than an hour. Sometimes just getting to the freeway and onto it can take 15 minutes.

And all bets are off if there's any kind of moisture on the roadway…

 

For my commute I leave it in EV, even on the highway, until I have approx. 4 miles of EV left, then I switch to HV. When I exit the highway, I switch back to EV and have that 4 to get me the rest of way to work on the battery. Going home, I do the same thing, as long as I could charge up at work. It usually leaves me .5 to 1.2 miles of EV left.

 

El Dobro,
It's not efficient to have EV battery left when you get to your destination.
So instead of switching to HV at 4 miles, switch at 1 or 2 miles. Then the EV battery will be used up and you'll finish the trip on the battery in HV.
It will raise your destination MPG.

 

One correction: it's not mpge, it's mpg. Mpge would be if the Prius factored in the amount of energy electric drive uses, which it doesn't. The only way to get mpge is to calculate it by hand.

 

yes. Why would you want the ICE to idle to warm up the car? You should be driving at 40 or 50 mph at least, IMO.

Mike

 

and, not in EV but ICE, right?

 

Yes.
You can't "warmup" the ICE in EV mode.

Mike

 

welL, DUH!

 

WELL, duh!

 

False. Press down on the brake and gas pedals and voila!