Most EV miles on one charge?

I drove 85 miles round trip, I know 100% for a fact that my gas engine did not kick on until I was approximately 8 miles from home at the end of the day.. Make of it what you will, it was around 77 miles round trip on EV. It was a large mix of rural country roads, highway (55mph speed limit where I was doing around 53ish) and interstate (70mph speed limit, I was doing around 65ish). Question my figure all you want, 77 EV miles out of 85 is what it was. I'll make sure I specifically take pictures next time for proof since I was able to do this the last 2 days I drove as long as I get similar weather I'm sure I can replicate.

 

It sounds like that last eight miles where the ICE kicked in was the uphill section of your trip, and that's why your EV-range estimate is exaggerated. You were going downhill in that section in the first leg when you got a good EV range, and you didn't use the EV battery in that section in the return leg.

Your actual EV range is certainly not equal to 77 / 2 = 38.5 miles, as evidenced by the fact that the return leg is more steep. It is in the low 30s.

 

Ours read 32 miles this morning. We have a 2017 with almost 200k miles.

 

however you want to justify it, 77 EV miles out of 85. no one lives in a vacuum of flat roads, all i can say is that it was not a lot of crazy steep hills one way or the other.

 

Right, I am not disputing the 77 / 2 miles average range on your two full charges. My point is that the EV range should be reported entirely round-trip, as any elevation difference makes a big difference in an EV with only a 30-mile range, as the total energy available in the battery is small, and the gravitational-potential energy becomes a significant fraction of it as a result. If you had a 300-mile-range EV, the effect of the elevation would be ten times smaller, but this is not the case with the Prius Prime, and the elevation shows up intensely in the numbers. In your case, your number is roughly 20% off, with the actual number probably being around 32–33 miles instead of the 38.5 miles average you observed in those two trips.

 

When puttering around my suburb and occasionally just outside of it, I typically get 53-56km from a charge (doing nothing in particular to “be green”). I’m happy to be well above the 40km “official range” according to Transport Canada.

Now that I’ve started my work commute again (seven round trips of 320km +/- 5km), almost all on autoroutes (interstate type), I’ve experimented a bit. I usually set the cruise control at 110km. The terrain varies from tabletop flat for the first/last 55km, to gently rolling hills for the next 60-65km, to a mix of long climbs/decents and short but steep ones over the last stretch, with the final decent/climb being both steep and long. On my way there, I usually run out of EV charge at 45-48km, but on the way back, I get 10-12 fewer km. Starting flat or starting with a steep climb makes a huge difference.

Overall combined efficiency for the round trip is notably better if I engage EV Auto mode as soon as I get on the autoroute than if I use up the charge first in EV Only mode. On the order of 15-18%. The efficiency gain is more pronounced at 120km/h than 110km/h (on a couple of occasions, time was tight). Overall efficiency, of course, is better at the lower speed. But even at 120, I’m literally sipping fuel. It’s 6 times better than my Xterra at that speed. (I always include the EV portion in my fuel calculations because, well, it’s there).

 

42.5 miles is now my most EV miles on one charge. This is my all-time high new record. It was a complete round trip in one continuous drive just in case someone is going to complain. Although I did stop at the turn-around point to drop off something, the car was never shut down for the entire round trip of 42.5miles. As before, the condition of the drive was average speed ~35mph with top speed ~55mph for a few miles on the segment with a speed limit of 50mph, all on rolling hills and valleys on rural roads (some state highway, some residential part of town) with relatively light traffic. But in actuality, as I was approaching my driveway, the EV range was depleted and the engine started... So, technically speaking, it was slightly shorter than 42.5miles. My average is now ~36 miles on a single charge with only 1.5 months of driving.

I hate to see the engine kick in on the very last few miles of my return trip. This happened very frequently on my previous 2017 PP for the ~35 miles daily commuting which was just slightly longer than the EV range on a full charge on the 2017 PP. With my new 2021 PP, I can finish the entire 35 miles commuting on a single charge with ease. At least this time of year without snow on the ground. I am now convinced that 2021 PP has a longer EV range than my previous 2017 PP. However, I also had 2020 PP, but did not drive it long enough or often enough to have any solid idea of how it compared to the other two model years. So, change might have already happened in the 2020 PP.

 

I have, sort of. But the data is still too small to make the difference statistically significant.

Here is the number of charges and average kWh took to fully charge the EV range depleted battery. All charges were by OEM L1 EVSE at 12A and measured by the same Kill-a-watt meter. Does not include any partial charge even if only 1% SoC was remaining when the charge session was started. Also does not include any charge session with climate control, battery heater, or battery cooler being on. For comparison purposes, I included only the first 4 months of data for the 2017 PP. I have more data for 2017, but comparing 2+ years old battery to a new battery is probably not a good comparison for this.

For 2017 PP Pr: average full charge 6.68kWh (n=50)
For 2020 PP LE: average full charge 6.86kWh (n=7)
For 2021 PP Lt: average full charge 6.80kWh (n=12)

 

Ah, you cheated there a little. However, you probably got close to 40 miles, which is very good.

I have verified through numerous trials that the longest round-trip EV range you can get with the Prius Prime is 42–43 miles, and that requires slow speeds (no more than about 25–30 mph average) and very little A/C load. The best you can do on a freeway round trip is in the low 30s. Of course, that number could become very high in stop-and-go driving, where the Prius Prime excels. I can easily get over 100 mpg true gasoline mileage in the HV mode in freeway stop-and-go driving, which puts motorcycles in shame.

That reminds that before hybrid engines were introduced, I was talking to a Ford engineer in an auto show, who claimed that they would have a diesel hybrid engine that gets 100 mpg.

 

Reposting from another thread:

New round-trip EV range and miles/kWh records: 47.0 miles round-trip on 100% SOC and 7.6 miles/kWh round-trip!



I took the advantage of the empty streets and drove about 25 mph to and from the grocery stores. I would probably achieve 50 miles if I didn't have the groceries loaded on my way back.

 

Congratulations!
You just self-contradicted your earlier very authoritative conclusive statement.

Now you know I did not cheat on my 42.5miles. Never underestimate the power of Prius Prime.

 

In fact, I forgot that my previous record was 45 miles. Now, my new record is 47 miles.

You did cheat a little as you described though.

 

If you call about 300 feet on the engine warm cycle a cheat, then it would be almost impossible to get 100% SoC used up exactly for a round trip. From the display you are showing, you certainly did not do that. You are just estimating the total EV range distance for a 100% SoC from a short round trip you did. That is certainly not the same thing as actually driving all 42.5 miles minus 300 feet on EV mode round trip.

 

Yes, the round-trip I used was 15.5 miles, and I used exactly 33% of SOC, with the gauge just switching down to 67%, which I then extrapolated.

300 ft is not much unless it's uphill. However, I don't understand how you can achieve 42.5 miles driving 35–50 mph. Also, the battery icon on your gauge is showing more like −5%, not 0%. It's easy to get inaccurate results because the range of the Prius Prime is short, and small errors result in large inaccuracies.

 

I did not say I drove 35–50 mph. If I kept my speed above 35mph all portion of the trip, I certainly would not get the average speed of 35mph. What I said was, "average speed ~35mph with top speed ~55mph for a few miles". That means my speed at most of the portion was way less than 30mph in order to get an average of 35mph on a 42.5miles drive. This is almost as slow as I can drive on this road without causing a major traffic jam.

In any case, although comparing one's EV range with others is fun, unless we are all driving the same road at the same time, any comparison is almost meaningless. There are innumerable variables that affect EV range and overall efficiency. There is no way we can account for all the variables and say, only the driving technique is the difference.

 

Do you ever get traffic jams over there? I guess they happen only when someone is hypermiling.

 

Yep, with dozens of pick-up trucks and SUVs behind. Oh, it can also happen with a tractor running at full speed on our road. This happens more often than hypermiler. And most drivers are more congenial to those who drive a tractor on public roads than to someone hypermiling on Prius. LOL

Are tractors allowed on the road? Here are the rules | AGDAILY

 

It would be embarrassing to be passed by a tractor while hypermiling.

 

just made it again into work 1 way, I repeat 1 way, engine kicked on as I was coming up to the stoplight to turn into my work parking lot. roughly 41 miles.