Road Trip - Atlanta to Amelia Island in HV-mode

[MajorAward]

Over the past week, I used the Clarity to travel from Atlanta to Amelia Island, FL, with multiple stops between. I wanted to use HV-mode for the entire trip and to try HV-charge, since I had never used it before. On Sunday morning I left Atlanta with a battery charge of 95%, and used HV mode all the way to my parents place in south Georgia, 250 miles away. I spent a few days helping paint, then took a day trip to Fernandina Beach, FL, one of my favorite places to go as a kid. This is from the first leg of the trip. As I decipher notes, will post more... Nothing scientific, just observations.

High Speed HV MPG

I was able to log the first leg of the trip. These numbers are from I-75 between Atlanta and Dublin, GA. Driving the speed limit on parts of that stretch can be dangerous, so lets say minimum 74mph to maximum 85mph. Many times it is stop and go south of Atlanta, but this was early Sunday morning, so except for a slight slowdown in Macon for bridge construction, it was a smooth trip. I used a method I saw posted by @AlAl in another thread to calculate mpg. That approach seems reasonable to me, so I used it here.

Starting EV range = 48.8 mi
EV range after fill-up = 46.0 mi
EV difference = 2.8 mi
TripA = 162.1 mi
Total Gallons to fill = 3.85 Gal

So:
(162.1 mi-2.8 mi)/3.85 Gal = 41.37 mpg

The Clarity is a nice comfortable car, so I am pleased with 41.37 mpg it returned in HV mode, particularly at high speeds.

 

[MajorAward]

Battery use in HV mode over multiple start/stops.

Sorry for the bad pic, but this is Georgia's high tech corridor along U.S. 441 south of Dublin, GA. Unless someone is working on stealth technology or some type of cloaking device, there is not much happening here. To be fair, there is a Husqvarna mfg. plant farther down the road, but still lots of space available for that high tech start up you always dreamed about

I made another stop at the Captain John Derst Discount Bread Store a few miles down the road. I can't quite figure out how this place stays in business, as there are never many cars there, but the bread is great and we stop there on many of our trips down, so maybe the answer is in there somewhere. While checking out, I saw a couple looking at the Clarity across the parking lot in front of the store. As I walked out the door I heard the woman ask her companion "What model is that?". That's all I heard, and don't know if the question meant she liked it or not, but they were definitely interested.

After starting the car, I noticed another bar missing from the battery gauge. Over the course of the trip after stopping and starting the car multiple times, It got as low as 10 bars, but then seemed to stay there over multiple starts several days into the trip. I really don't know why, or if it would have continued to decline at some point. I suppose it would, but, at least on this trip, it never did.

 

[MajorAward]

LKAS


This is U.S. 1 south of Waycross, GA, near the entrance to Okefenokee Swamp Park. The Fog sits just above the ground sometimes until late morning, but this road is a well-marked 4-lane divided highway, with miles and miles of relatively flat smooth pavement, an occasional curve, and the occasional hill.
The LKAS does a really good job on roads like this. At one point I drove slightly over three miles without having to really steer at all, just lightly touch the wheel to keep the system from scolding me. There are roads down here, particularly county maintained roads such as this:

But also some two-lane state roads as well, where the system has a hard time. Road markings can change abruptly at county lines, and this caused issues with the LKAS. I really don't see this as a problem, though. I think we all realize the Clarity is not a self-driving car, so I doubt any of us would try to read a book or take a nap while driving.

 

[MajorAward]

Gear Lockup


It is possible to find county maintained roads in south Georgia where you will not pass another vehicle for five miles or more. These roads were good for all kinds of shenanigans when I was a teenager, but today, we get to test gear lockup. Looking at the driver display I observed gear lockup as early as 43 mph, but didn't see it start to charge the battery before 45 mph. On one attempt I was able to keep it at 43-44mph for what seemed like several minutes, but probably was more like one. So I observed lockup as low as 43mph and as high as 80mph on this trip. 80mph may not be the limit, just the highest I observed on the display. I was a little surprised with the amount of time gear lockup stayed engaged, sometimes staying locked while climbing slight inclines for a period. I also noticed it engaged and disengaged quite a bit on the more rolling terrain portion of the trip, so hope the clutch system Honda uses in the Clarity is robust.

 

[fotomoto]

Thanks for the report of your trip observations. Hope the painting was indoors!

After starting the car, I noticed another bar missing from the battery gauge. Over the course of the trip after stopping and starting the car multiple times, It got as low as 10 bars, but then seemed to stay there over multiple starts several days into the trip. I really don't know why, or if it would have continued to decline at some point. I suppose it would, but, at least on this trip, it never did.

Hmm, possible hypothesis: Gauge/car is just using the top two bars as the bottom two hybrid bars while in HV mode? I always use some EV to get out of town before switching to HV so I've never started a trip yet with 100% SOC. Interesting.

On one attempt I was able to keep it at 43-44mph for what seemed like several minutes, but probably was more like one. So I observed lockup as low as 43mph and as high as 80mph on this trip. 80mph may not be the limit, just the highest I observed on the display. I was a little surprised with the amount of time gear lockup stayed engaged, sometimes staying locked while climbing slight inclines for a period.

IMO, Honda determined ICE (gear) drive is the most efficient to maintain speed in these scenarios instead of going the ICE>generator>battery>traction motor or ICE>generator>traction motor routes and the ensuing transmission losses inherent with each transfer. Makes sense as every plug-in hybrid with the exception of the volt and bmw-rex do this in some form or fashion. GM grudgingly later admitted they do it too in HV mode. Electric is most efficient at lower speeds while gasoline gets more efficient at higher speeds. Another beauty of a dual fuels powertrain.

 

[MajorAward]

Climate Control


Early mornings at Amelia are usually pleasant. By 10am if not before, the heat moves in. But even in the upper 90 degree not-a-dry-heat of Amelia Island, the Clarity A/C system was top notch. I never had more than four adults in the car at any time during the entire trip, but the interior remained comfortable for everyone. Rear seat passengers were very appreciative of the center console vents, as they remembered my old Subaru Outback didn't have them.

But the harshest critic, Lincoln the wonder dog, seen here hanging out on the dunes at Amelia, will let you know fast if he isn't comfortable. Well, not to worry, the Clarity is Lincoln approved. He spent most of the trip stretched out in his pet hammock in the back seat area.

 

[MajorAward]

HV Charge mode


You wouldn't know it by looking at the picture, but Camden County is home to the Atlantic Fleet's Ballistic and Guided Missile Nuclear Submarines,located at Kings Bay. There is a 20 or so mile stretch of U.S. 17 that runs from Yulee, FL to Kingsland, Ga that offered the perfect opportunity to try HV Charge for the first time. As I mentioned in an earlier post, I never saw my battery level dip below 10 bars during this trip. On the way back from Fernandina Beach I knew I needed to fill the tank when I reached Kingsland, so once I turned north on 17 and cleared traffic I engaged HV Charge mode. I wish I had timed it, but didn't. Many miles before I reached Kingsland, however, HV-charge moved the guage from 10 bars to 13 bars, then informed me it had charged as much as it could, and that I should plug in to finish the charge. It then changed to HV mode automatically, and we continued on the way.

I did not make any more stops before arriving back at my parents home about 110 miles from Kingsland, and still had 13 bars when I arrived. I made one more trip to a neighboring town about 25 miles away, and the next morning when I started I had 12 bars. I made one stop on the way back to Atlanta to refuel, and arrived back home in Atlanta with 11 bars left on the battery gauge, as I used HV the entire trip.

 

[MajorAward]

Final Thoughts

Atlanta to Amelia is a trip we make a few times a year. We have a family vacation there once a year, my wife's brother retired there, and we are thinking about it a few years from now as well. Over the years I have made many trips there in many vehicles. Some forgettable, some memorable. I've owned practical cars, fast cars, even trucks, but my favorite all around fun car was a 1983 Saab 900 Turbo w/ standard transmission.... Until now. I have never had so much fun as with the Clarity over the past few months. I know it doesn't have a standard trans, turbo, etc., but just trying to figure it out is a game I love to play. Heck, if you are into technology at all, you've got to love this car. It is more entertaining than most movies I've seen lately.

 

[insightman]

IMO, Honda determined ICE (gear) drive is the most efficient to maintain speed in these scenarios instead of going the ICE>generator>battery>traction motor or ICE>generator>traction motor routes and the ensuing transmission losses inherent with each transfer. Makes sense as every plug-in hybrid with the exception of the volt and bmw-rex do this in some form or fashion. GM grudgingly later admitted they do it too in HV mode. Electric is most efficient at lower speeds while gasoline gets more efficient at higher speeds. Another beauty of a dual fuels powertrain.

Clearly, Honda would not expend the engineering efforts, greenlight the additional manufacturing costs, and accept the attendant space requirements and weight penalties of the Engine-drive mechanism unless it provided greater efficiency for a significant percentage of the Clarity's travel.

 

[2002]

Hmm, possible hypothesis: Gauge/car is just using the top two bars as the bottom two hybrid bars while in HV mode?

Haven't studied it that closely yet but I assumed the bars probably line up with the SOC as reported by the app. In other words the twenty bars each represent 5% SOC. EV runs out at about 10% according to the app, so two bars. I did get to I think 1% one time (or was it 3%) sitting in a parking lot running the AC until the engine came on. But it was still one bar not zero bars, maybe you really have to hit 0% to get zero bars, if that's possible. Not that I plan to try.

At one point I drove slightly over three miles without having to really steer at all, just lightly touch the wheel to keep the system from scolding me.

Slightly banked curves help, less torque needed to steer. Actually I have found that many curves it isn't so great at starting the curve, but once in the curve as long as it's not too sharp of a curve it can usually manage things and usually pulls out of the curve nicely. Relatively new paint markings help, I'm not good at estimating the age but I would say up to maybe two or three years, once the paint starts to fade or get dirty it's doesn't follow quite as well, it can do okay but is more susceptible to other factors such as poor lighting. Lighting is important, needs consistent light. I was on a road and it was doing fine until there were intermittent shadows caused by trees and this kept it from tracking. Shortly afterwards there was a solid line of trees and thus solid shadows and it was fine. There's a thirty-five minute drive each way that I do twice a week, one morning it was one of those really clear mornings and the sun was behind me and I thought the car could have driven itself practically the whole way if I had let it. The same trip another day in the afternoon with the sun in front of me, not nearly as good. Going past an exit lane where the right-hand stripe starts to move off to the right, the car almost always tries to take the exit (maybe it thinks I need a break). I have learned to just assume it will do this and be ready to resist with some steering input to the left.