[p__x]

This past weekend my son's team played in the hockey league weekend in Knoxville, TN, so we had to travel out of town again. This time I decided to take my 2022 AWD ID.4 on the trip instead of taking the Model Y for two reasons:
1. I'm trying to trade my low-milage 2021 Model Y for a 2023 Model Y, so I don't want to put any more miles on it until I receive the trade-in estimate on the 2021 Model Y from Tesla.
2. The hockey rink in Knoxville is just a little over 200 miles from my home in a north Atlanta suburb, so this trip is definitely more feasible in the ID.4 than my previous trips. Additionally, there is a convenient EA charging location east of Chattanooga, TN on Little Debbie Pkwy (about 120 miles from my house and about 75 miles from the hockey rink in Knoxville).

So, I only needed to stop once at a DC charger on the way to the hockey rink. In fact, I could have (in theory) made it all the way to the hockey rink without charging on the way, provided I left home with 100% SOC, but that would have prevented me from being able to drive at the destination without finding a place to charge, and this particular hockey rink doesn't have EVSEs on its parking lot (or nearby), so making this 200-mile one-way trip without charging on the way wasn't possible.

This time I decided to precondition the cabin (the first time ever) and charged to 100% at home before we left for Knoxville TN on a Saturday morning. 200 miles of driving would normally take us less than 4 hours (with a 20-30 minute stop at a nice coffee shop somewhere in the middle of a trip). About 30 miles of the first leg of the trip (between home and the EA charging location) were driving in the city, while the rest 90 miles were driving on I-75. We got to the DC charging station on Little Debbie Pkwy with 47% SOC. My dilemma was, What percentage do I charge to in order to be able to spend the weekend in Knoxville, driving between the hotel and the hockey rink multiple times? Based on my previous experience traveling in the ID.4, I decided to charge to 100%. This EA charging location has 8 charging pedestals (2x350kW and 6x150 kW). Since there was no one charging at the time, I decided to try the 350 kW pedestal to see what my charging rate would be. By the time we got to the DC charging location we had driven for a little over 2 hours plus the car sat in the garage prior to our departure preconditioning the cabin for 1 hour (while charging to 100% SOC).

My charging rate at the 350 kW EA DC charger started at 56 kW and went as high as 61 kW. It never exceeded 61 kW, which was a bummer. The ambient temperature was 56F. So, after 1 hour of preconditioning the cabin manually plus setting the departure time in the ID.4 infotainment to 9:00 AM (to hopefully precondition the battery) and then driving 2 hours in the ambient temperature of 50-55F, the maximum charging rate I could get at around 50% SOC was only 61kW. I took about 52 minutes to charge from 48% to 100%.

When we got to the hockey rink, we had over 60% of SOC left to use during the hockey weekend in Knoxville. We made two round trips between the hotel (15 miles away) and the hockey rink on Saturday, kept the climate at 70F for our dog to be comfortable inside the ID.4 during the games, and then we made one more such round trip on Sunday and again enabled climate at 70F - all of this without having to charge our ID.4. By the time we were ready to leave Knoxville at around 1:00 PM on Sunday, we had 32% SOC remaining in the ID.4. There was not enough SOC left in the ID.4 to make it back to the EA location on Little Debbie Pkwy in Collegedale, TN (just east of Chattanooga, TN), so we had to drive about 7 miles east (in the opposite direction of home) to get to the EA station on Walbrook Dr in Knoxville. There, I decided to charge just for 30 minutes - just enough to get us to the EA location on Little Debbie Pkwy in Collegedale.

I got to the EA location on Walbrook Dr, Knoxville, TN with 29% SOC. The ambient temperature was 46F, and my charging rate got to 53 kW. I was plugged in to a 350 kW charger because there was another ID.4 plugged to a 150 kW charger, the CCS/CHAdeMO charger was vacant, but I figured I wouldn't use it in case a Leaf showed up, and the fourth charging pedestal (also a 350 kW one) was broken. This location only had four DC pedestals. The other ID.4 left shortly, but I was already charging at the 350 kW pedestal, so I decided not to interrupt my charging station. Next to me pulled up a brand-new IONIQ5 and plugged in to a 150 kW pedestal. The owner had just bought the AWD IONIQ5 at MSRP in Kentucky and drove it home to Knoxville the day prior. He said he almost ran out of charge on the way from Kentucky to Knoxville because the range he was getting was nowhere near the advertised range for the IONIQ5 of over 300 miles. The guy was not yet an experienced EV owner: he didn't know that the charging rate was measured in kW, that his battery capacity was measured in kWh, how to relate kW to kWh, etc. So, while we were charging next to each other, I gave him a little lesson in charging speed, battery capacity, preheating the battery for DC charging, etc. In return, I asked him to show me the cargo space in his IONIQ5 and compared it side by side with the ID.4. The IONIQ5 cargo space is significantly smaller, and there is no space under the cargo floor, so I'm again glad I didn't buy an IONIQ5. This guy came to the EA DC charging station with 30% SOC, and when he plugged in, his charging rate went up to 78 kW very quickly and then just hovered around 78kW. The guy didn't know that he was supposed to plug the EA location in his onboard navigation unit to get his IONIQ5 to precondition the battery for the DC charging session. He assumed it happens automatically, so he navigated to this DC charging station, using Google maps. I told him that to charge at a higher rate, he needed to use his onboard navigation to navigate to the EA charging location and thus have the IONIQ5 precondition the battery.

Then, on the other side of my ID.4 pulled up an EV6. The guy in the EV6 plugged in to the 150 kW pedestal with the CCS/CHAdeMO handles and started charging at 72 kW. I asked him if the EV6 has the battery preconditioning feature, and he said that it's rumored that the EV6 was about to get this feature via the software update, but it didn't have it yet. I read somewhere that the IONIQ5 got the battery preconditioning feature via a software update relatively recently, so I do believe it's coming to the EV6 soon. The cargo space in the EV6 is even smaller than that in the IONIQ5, so even though I like the EV6, it's way too small for my family needs.

So, both the IONIQ5 and the EV6 were getting about 50% faster charging at 46F than my 2022 AWD ID.4 was getting.

On the way back home to Atlanta, we got to the EA station on Little Debbie Pkwy in Collegedale TN with 20% SOC. This time I decided not to charge to 100% because we were navigating home, and I have a Level 2 EVSE at home. I used ABRP (with a Bluetooth dongle connected and a premium subscription activated) to specify that I wanted to get home with 20% SOC (I like having at least 20% SOC remaining upon reaching home just in case) to figure out to what SOC percentage I needed to charge at this EA location. I plugged in to a 150 kW charger at this EA location and with 20% SOC my charging rate went up to 94 kW right off the bat. I was impressed, not expecting to get higher than 60 kW. I charged to 80% SOC, and it took 36 minutes to get from 20% to 80%. This was the best charging speed I was able to reach during this past weekend's trip, and I'm not sure why the charging rate was so high (relatively speaking), while the ambient temperature was still 46F.

These are the SOC levels and the charging speed during this last charging session:
20% SOC - 94 kW
33% SOC - 93 kW
44% SOC - 85 kW
50% SOC - 81 kW
56% SOC - 75 kW
64% SOC - 63 kW
73% SOC - 55 kW


So, I had charged at an EA location in Knoxville TN (Walbrook Dr) for 30 minutes, then drove for 1 hour 20 minutes, and immediately plugged in to an DCFC pedestal at the EA location at Little Debbie Pkwy in Collegedale, TN, and my rate was 75% faster (93kW vs 53 kW) at the same ambient temperature than it was charging at the EA location in Knoxville 1 hour 20 minutes prior, with me using a 350 kW pedestal in Knoxville vs using 150 kW pedestal in Collegedale. I can't explain this huge discrepancy in the charging rate, especially because I charged at the same Collegedale, TN EA location the day before with the charging rate not exceeding 61 kW after a two-hour drive from Atlanta with the ambient temperature being 10F higher (56F charging at 61 kW /47% SOC - on the way from Atlanta to Knoxville vs 46F charging at 83 kW / 47% SOC on the way from Knoxville to Atlanta). The only variable between the two charging sessions was that on the way from Atlanta to Knoxville I first charged at home at an L2 EVSE, while trying to precondition the cabin / battery the best I could, while on the way from Knoxville to Atlanta, I first charged at a DCFC in Knoxville (29% SOC to 69% SOC for 30 minutes).

While I was charging my ID.4 at the Colelgedale EA charging location, another ID.4 pulled up to a neighboring EA stall at 29% SOC and started charging at 74 kW (at 46F ambient temperature). My rate at 29% SOC a few minutes prior was about 94 kW. The only explanation I can think of is that charging at a DCFC for 30 minutes and then immediately driving for 1 hour and 20 minutes significantly warms the battery for the next DC charging session, and thus improves the charging rate significantly, but all of this has to be done back-to-back without any time wasted for idling the ID.4.

The efficiency I had on the way there and on the way back averaged at 2.7 miles/kWh. I set the ACC at 75 mph, but my average speed on the way back calculated by the ID.4 computer was 65 mph (before I got off the interstate highway in Atlanta). So, I believe this is the best efficiency one could achieve in the AWD ID.4 driving at moderate highway speeds between 40F and 60F. This would give one a range of 207.9 miles on 100% SOC (2.7 miles/kWh * 77 kWh) . In reality, because EA stations are placed so far apart in the Southeast (in this case they were 80 miles and 100 miles apart between Atlanta and Knoxville), the actual range of the ID.4 along a road trip is significantly less than 200 miles (unless you want to stop at a hotel (with a L2 EVSE) overnight to get yourself back to "full tank" by the morning. Basically, you have to stop every 1.5 to 2 hours for about 30-40 minutes with the temperatures in the range of 40F - 60F to be able to get yourself to the next EA charging location while on a long road trip. If you want to do 400 miles of driving per day, you are going to spend between 2.5 and 3 hours charging (4 charging stops) and 7 hours driving - as long as you are disciplined enough not to extend your stops beyond the time required for charging. In the summer, it's probably possible to limit the charging stops to 30 minutes (to get all your charging for free) and still be able to do this sort of a long trip.

It would be an interesting experiment to set the cruise control to 65 and see how much more driving you'd get. THeoretically it could give you 30% extra range at the expense of 15% lower speed.

 

[p__x]

The problem is I wouldn’t live to see the result, and neither would my family. So, I’d say the chances of this happening are nil.

Exactly what I was thinking, driving 65 on I-75 puts you in the bullseye of some very impatient people, not to mention a Kenworth grill in your rear window.

It’s always doable one way or another. Worst case scenario, you’ll glide behind the truck that’s paying your aerodynamic penalty.

 

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Or you’ll be gliding in front of the truck pushing you to the next stop. At least that’ll be efficient!

Seriously though, if the traffic flows faster than 65 MPH, you can find a truck and glide behind them.
The truck braking air resistance in front of you will pay off the drag penalty of the higher speed. And there always a truck.

I'm saying this because of a time-efficiency perspective your actual speed in an EV is a combination of driving speed and charging speed (see math below). Your range 100% to 10% speed at 3.5 mi is 240 mi + 30 min charging i.e. around 4.5 hours (about 50MPH).

So yeah at 2.7Mi/Kwh you can't do 200mi in a single leg but at 3.5 mi/Kwh you can easily do it and well within the expected 4-hour time frame by OP.

Again, what I love about EVs is that we actually face the thermodynamic costs of a trip and realize that going slow can be faster, instead of speeding thru the trip using carbon debt on dino juice.

*At 3.5mi/KWh and charge in the 20-80% range (50KWh), that's let's say 65 mi/H, then you can go
175 miles in 2.5H, stop for 30 min (assuming ~90KWh charging speed)
So it's 175 mi every 3hours, i.e. ~58MPH speed.

 

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Hyper drafts are a non-starter on I-75 north of Atlanta due to hills. That plus reacting to tire carcasses and debris being thrown at you. Gas is not expensive enough to justify such.

The truck also breaks your windshield by spewing rocks at it. Happened to me two weeks ago on the way from Atlanta to Nashville. Have a chip in the windshield because of trying to glide behind a truck. Good advice!

Not like these aren't issues and risks with cars in from of you. Just because you're behind a truck it doesn't mean you can't keep safe braking distances. But I give up

 

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Yeah we have done this at 65 mph a lot actually for long trips. Find a 65mph calm truck or semi, follow with ACC set at the furthest distance (so not helping with wind resistance but thats okay). Faster cars / trucks stay on the left lane. Then my mind can wander, have deep conversations with passengers or even karaoke So far so good no cracked windshield (YET! 🤞)

Speaking as a former truck driver, we don't mind four-wheelers following as long as they don't hang off our trailer tandems. If you can't see the driver's face in his mirrors, he can't see you. And that makes him nervous. And maybe he'll light up his brakes with a wee tap on the trailer brakes, just to back you off.
The trick here is to draft a union driver. They get paid by the hour, and are usually speed-monitored by computer: Schneider. Roadway. Wal-Mart. It's the owner-operators and small independents--flashy Kenworths, Western Stars, and Peterbilts with beetle-brow chrome sunshades--that you want to avoid. Those guys get paid by the mile, and the more they can roll up without running afoul the logbooks the more money they make.

Yup. People have this idea that you have to really closely tailgate the truck to get drag reduction. It's actually still 11% at 100ft and about 5% at 200 Ft.

(Blue as measured by mythbusters, dotted, using a logarithmic model).

Dropping speed from 75 to 65 MPH reduces drag by 30%. You add another 5% on top of that safely behind a truck at a distance that you see the driver in their mirror. That's an easy boost from 2.7mi/KWh to 3.6mi/KWh or a range boost from 190 to 250 mi from 100% to 10% charge. People will also be much less inclined to push you off the road if they see a truck in front of you.

We need to make sure there is a semi for each EV traveling on the highways so that EVs can be used for road trips. I’m thinking about making an app for EV drivers to find a truck to follow.

Or, we can start bying EVs with decent range.

Sarcastic you may be, most people aren't roadtripping in their EVs so there's plenty of trucks in the sea and spending more money (and carbon) just to release more carbon is a strategy that got us where we are headed right now. (Not that hypermiling is comparable to the scale of other emissions sources).

 

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Personally, I’m completely opposed to following trucks for various reasons, including the aesthetics of riding hours behind an ugly rear end of a truck and looking at it for hours on end. That’s not a good way to travel as far as I’m concerned. I don’t even see a point in bying an EV if this is the way that we should travel in them. All other things, such as flying rocks into your windshield, being the slowest car on the road, breathing the truck’s exhaust, etc. only add to the experience. An EV should be able to road trip without having to hitch a ride behind a semi, which is exactly the polluter that we need to take off the roads instead of utilizing them to make EV road tripping possible.

Sure. you pay up, propel the tech, I buy in when cheaper. We both happy.