Over the weekend my wife and I took her 2018 Clarity Touring on an 874 mile road trip hunting for waterfalls. There’s so much snow left in our mountains that even seasonal waterfalls are easy to find. Just driving along you would see waterfalls where the highway is cut into mountain sides. Because Colorado is altitude crazy I’m including altitudes in the road reports. The trip started over 1 mile above sea level and traversed roads that went over 2 miles above sea level.
: Left home (5,700 ft) and drove to Ouray (7,760 ft.), CO via Rifle Falls State Park and the Grand Mesa Scenic Byway (11,237 ft). This drive went through the west bound bore of the Eisenhower Tunnel (11,158 ft.) and Vail Pass (10,662 ft). These are the two highest points on the US Interstate System. I refilled the gas tank in Ridgeway after 360 miles of driving. Leaving Rifle Falls State Park I screwed up and didn’t get the car back into HV mode so when I started the 6,300 ft climb from the exit off I-70 to the Grand Mesa I had zero battery. The car’s ICE screamed the entire way up at the posted 45 MPH. I’m not sure it would have made it up some of the other high speed passes without battery. This is why Honda provided the HV Charge mode – to give drivers who find themselves without battery the ability to provide some charge before climbs like this. On the way down from Grand Mesa I regenerated almost a third of the battery.
I figured out why the engine was screaming while climbing up Grand Mesa. The car called for EV power when there was no battery - the battery state of charge (SOC) showed a single bar and not normal two bars of a depleted battery. The screaming stopped once the car brought SOC back to two bars. During the ascent the car was pulling the power from the battery as fast as the ICE could provide it while directly connected to the drive wheels.
: Out and back from Ouray to Telluride (8,750 ft) – 50 miles each way, crossing the Dallas Divide twice at just shy of 9,000 ft. Between Telluride and Dallas Divide is Placerville, CO at 7,323 ft. On the way back there is a 13 mile climb from Placerville to Dallas Divide. I managed the battery and ran out of battery on the return approach to Ouray.
: Ouray to home via Red Mountain Pass (11,018 ft), Wolf Creek Pass (10,857 ft.), Poncha Pass (9,010 ft), Red Mountain Hill Pass (10,051 ft.), and Kenosha Pass (10,000 ft). A couple of hundred yards from the top of Kenosha I put the car back into EV mode, knowing that I was looking at a 4,300 net elevation drop from there to home. There are some steep climbs on that final route, including a 2 mile long 7% grade eastbound out of Bailey. I ran out of battery less than half a mile from my house.
Total distance was 874 miles; Trip A MPG reported 61.2 MPG. I started each day with a full battery. The attached image is the Trip A final MPG number.
This is a heavy car and neither the ICE nor the EV motor is capable of propelling the car under all situations by themselves. This car depends on both power plants to get full HP and torque. The use of ICE by the car is documented in the owner’s manual. The use of EV by the ICE is implied with the HV Charge mode, but not explicitly documented that I’ve been able to find.
The Adaptive Cruise Control (ACC) can run from very smooth to very jerky. On four lane roads I found that setting the following distance to the minimum worked best. On two lane roads I used the longest following distance. I tried the regular, non-ACC cruise and discovered that this mode doesn’t show the set speed. Dialing down the ACC set speed more than one or two MPH at a time causes the car to decelerate hard via regenerative braking. When dialing up the ACC set speed in Eco mode results in a very slow acceleration. In normal mode it’s a more reasonable acceleration. I didn’t try this in Sport mode as I only used Sport when I needed instant manual transmission type response to the throttle, such as when passing on a two lane highway. I also discovered that you need to keep the ACC set speed set at one MPH higher than the desired speed as the car spends a lot of time at one and two MPH below the set speed.
The regen paddles came in handy during long descents, especially when approaching sharper curves in the road. They work at all speeds I was driving, from 25 MPH posted limits to the 65 MPH descents along I-70.
One warning in the owner’s manual that my experience says is a non-issue is the one about ACC being disabled on long steep descents to avoid overheating the brakes. Even on 7 to 10% descents the car stayed in regenerative braking and didn’t touch the friction brakes.
The weakest part of this car’s vehicle controls is very definitely the Lane Keep Assist System (LKAS). LKAS and I fought a lot as I like to ride the “outer” edge of the lane to give myself more time to respond to oncoming traffic. LKAS doesn’t like this so I moved in slightly, but it still had issues every single time I came across one of the temporary turn lanes that caused the driving lane to “divide” into two lanes with one lane being the turn lane. It also had occasional problems with crack seal asphalt.
The other item that occurred was the “brake” warning popping up with on-coming traffic before the road actually started to turn to the right. Once the steering wheel was turned to follow the road this system appears to work properly. This issue is documented in the owner’s manual.
- Generally very quiet
- Comfortable to ride in all day
- Regen paddles work better than I expected
- Downhill regenerative braking is very efficient
- No spare tire - I'd rather limp along at 55 MPH than wait for a flatbed.
- ACC can be jerky
- ACC overshoots badly when accelerating and decelerating. The only car I've driven without this problem was my 2012 Cruze ECO Manual
- LKAS needs work as it gets confused by lane divisions and crack fills.
- Heavy car - doesn't corner as well as other vehicles I've driven
- Steering Wheel buttons have a loud click - tactile feedback is sufficient
For a similar report on my 2017 Volt, take a look at Mountain Mode not needed (Gen 2 Volt)
. The Clarity is definitely more efficient on long drives than the Volt.