San Diego to Las Vegas road trip- sustained high RPM/angry bees

Discussion in 'Clarity' started by Vitamin P, Nov 28, 2019.

  1. We took our first long road trip with the Clarity last weekend, San Diego to Las Vegas and back. The car ran great other than up the steep mountain passes, where I got angry bees and high RPM's for long periods of time, about 8-15 miles continuously. I had an OBDLink MX dongle connected, and it was registering RPM's in the 4500-5200 range during the climbs. It was pretty disconcerting to hear the car rev that high for periods of 10 minutes or more continuously, it sounded like we were stuck in 1st gear the whole time.

    I was in HV Sport mode, and battery SOC was around 80% at the start of each climb, dipping to about 65% at the lowest. Speeds were high however to keep up with the heavy traffic flow and short spacing between vehicles, usually 75-85mph (anyone that's driven the I-15 corridor going to Vegas knows what I'm talking about).

    Is it normal for the car to rev that high for that long under those conditions? Should I have maybe used HV Charge instead? The car seemed to have plenty of power available during the climbs (the power gauge never went higher than the 5th mark or into the solid white section), and I never had to floor the pedal or go past the click, but I was also afraid to try that because the engine sounded so mad already, I didn't know what would happen if I floored it.

    Any thoughts? It just seemed like the car really didn't like those grades, despite having plenty of speed and power.

    The Clarity (and hybrids in general) are new to me, so I don't know if this is normal behavior, or if the engine is designed to run like this.
    Clarity_Newbie likes this.
  2. JCA

    JCA Active Member

    My opinion -- this is perfectly normal and not bad for the engine at all. You're climbing some very long step grades at high speed; if you were in many regular small cars you or the transmission would have to downshift and the engine would rev pretty high; I know my Civic would downshift and be at 4000+ RPM and pretty audible in those conditons too. The computer certainly isn't going to let the engine overspeed.

    The Clarity has a relatively small engine for the weight of the car (compared to, for example, the Accord Hybrid), so it's going to rev higher to generate the same power, and it does sound a little less "refined". And hybrids in general can feel disconcerting because the engine speed isn't as directly related to the accelerator position or road speed; it can feel like a "slipping" transmission or like it's in the wrong gear. Our Highlander Hybrid is similar (albeit with a larger slightly quieter engine...and half the MPG of the Clarity and no plug-in/EV operation).

    I've both done "normal" mountain driving (sea level to 7000 feet through Kings Canyon/Sequoia NP in HV mode), and a test where I let the car go to 0 EV and pushed it hard up some steep foothill grades to see. In both cases the car drove just fine, with engine revs up to 5500 RPM at times.

    Some people don't prefer the sound, and switching off HV mode and trying to stay in EV mode (keeping the power meter in the blue; many of us use Econ mode to make that easier) can minimize it. You may or may not be able to sustain 80+ up a steep hill for very long though.
    Walt R, 4sallypat and Robert_Alabama like this.
  3. craze1cars

    craze1cars Well-Known Member

    Normal. Very small naturally aspirated engine in a very heavy car pulling steep hills at high speed with some altitude. Won’t hurt a thing. Floor it at will, it’ll just rev harmlessly a little higher.
    Last edited: Nov 28, 2019
    4sallypat and Robert_Alabama like this.
  4. Sandroad

    Sandroad Well-Known Member Subscriber

    Well, 75-85 mph up those steep passes between San Diego and Las Vegas with a 2 ton vehicle is going to make any car engine work very hard. Your Clarity was acting normal, in my opinion. You describe plenty of power and speed, which is amazing on I-15 going east at those speeds. the engine has to rev high to generate enough HP to keep your Clarity moving. And remember, the engine is not directly connected to the wheels, so it's free to spin up to any rpm necessary to generate the needed horsepower.
    Walt R, 4sallypat and Robert_Alabama like this.
  5. dnb

    dnb Active Member

    Since I don't think anyone else covered it, HV Charge would be worse because that means it would be only using the gas engine which is lower powered. "EV only" (turn off HV, it will still likely use gas if you go past the click point) would be less noisy as its using the bigger EV engine, but it will burn through your battery power super fast.

    But yes, as others said, any noise, especially the "angry bees" really stand out in this car because its usually silent while other cars are noisy all the time. I've recently driven two rentals while out of town and both were Hybrids, and both constantly had an angry bees noise when just going around in the city :\. Really made me appreciate how quiet my car is most of the time even going 65mph on the freeway in EV mode :D
  6. ClarityBill

    ClarityBill Active Member

    My approach to hills is a little different. I don't like the noise of the high rpms.

    I call it an HV reset. When the rpm's start to climb, pushing the HV mode button twice, about 2 seconds apart, causes the gas engine to drop back into gear mode, and reduce the rpm's. This causes you to lose about 5% of the battery charge with each reset, but rpm's stay low.

    I use HV charge on the downhills to recover charge.

    This whole process is about manipulating the way the computer controls the gas engine. Running the hills on EV eats up the battery very quickly, keeping the engine running reduces the amount battery charge that is lost. Staying in HV does keep / recover the most battery charge, but rpm's go high.
    Walt R, 4sallypat and Robert_Alabama like this.
  7. insightman

    insightman Well-Known Member

    Does this trick work for you every time? I've never been successful trying to force "gear mode," but I'll try your double-push technique next time I'm out.

    Edit: Just returned. The trick didn't work the first 4 times I tried it, but then it did work the 5th time. More experimentation required.
    Last edited: Nov 29, 2019
  8. Ryan C

    Ryan C Member

    I just did the Vegas drive from Riverside. I love my Clarity but I hated every minute of that drive. I got the angry bees and it was not enjoyable to listen to nor experience. I experimented with different modes but never found anything that seemed to make a measurable difference. While it got the job done and averaged a shade over 40 mpg I am just accepting the fact that it’s just not the optimal scenario for this car. I’m very happy to be in a place where 40+ mpg is disappointing and I am pleased to know the Clarity operated fine, just not great.
    But yes operating on long distance climbs and cruising at 80 mph and still having people blow by me was not fun. I did get a greater understanding of the limits of the vehicle and where compromises were made for efficiency. Still love it...did not love that drive.
  9. Clarity_Newbie

    Clarity_Newbie Active Member


    The results posted off the OBDll device are very much in-line with the data I've collected off multiple Clarity's. There are several threads with out there with RPM data if you are interested in "comparing".

    The mode won't change a thing RPM wise. As a guide...for the typical, follow the speed limit driver...the data collected indicates the Clarity will operate in the 1000 - 3500 rpm range majority of the time. 3500 to 4500 occurs intermittently depending on various factors with only rare occurrences above 4500 typically associated with steep(er) grades and or excessive speed.

    Goes without saying speed, topography, SoC, your personal driving habits etc etc etc will influence RPMs.

    Hope this helps.
  10. Thanks for all the replies and advice. I had also cross-posted this question to the Clarity Facebook group, and it's good to know that the car was performing within normal limits. Being new to the car, it just didn't sound like that to me at the time, so I just have to get used to that engine sound during times of heavy loading, which in my case should be pretty infrequent.

    I came to the Clarity from a 2000 Accord V6 that I drove for 264,000 miles, and our other car is a V6 Highlander, so these newer and smaller 4-cylinder engines are a new experience for me, especially the Atkinson Cycle engines. Someone on the Facebook group thinks that these engines probably don't redline until you hit about 8500-9000rpm, so the 4500-5200rpm my car was hitting leaves quite a bit of overhead.
  11. ClarityBill

    ClarityBill Active Member

    I am getting pretty good with the trick. I have found too much time between pushes will cause the engine to stop (EV mode entered and released - loses too much charge before restarting engine). Pushing too quickly will be no impact. I normally can wait for "HV Mode Off" display after the first push, then second push, then "HV Mode On" displays.

    Each push of the button needs to be more than just a tap of the button.

    Also, need to wait until after the engine warmup is complete.

    What happened when it did not work?
    Robert_Alabama likes this.
  12. Sthomasa

    Sthomasa Member

    My trip So. OC to vegas and back. Started full, full. Made it to stateline before adding two gallons. Did a full charge at Venetian (free parking, free charge.)
    Put four more gallons in and made it home with 30 miles of HV left. 586 miles, gauge read 48 mpg. My 2017 Accord hybrid, never got over 40 and angry bees up the steep hills. I thought Accord hybrid and Clarity share same engine?
  13. craze1cars

    craze1cars Well-Known Member

    This is not the case. Redline for this car is either 5,500 or 6,000 max...I forget exactly. But it is no more than 6k.
  14. Good to know, I'll have to see if I can find the actual spec.
  15. insightman

    insightman Well-Known Member

    I was going 65 mph on the e-way. After traveling in HV for 15 minutes to warm-up the ICE, I pressed firmly once to turn off HV, waited 2 seconds, pressed firmly a second time. On the first 4 tries, the ICE came back on, but the gear icon did not show up. I was sure the trick was not going to work for me, but tried again, still going 65 mph, just before getting off the e-way--then it worked.
  16. insightman

    insightman Well-Known Member

    The Accord Hybrid (and the CR-V hybrid) has a 2-liter, 143-hp unit, half-a-liter more than the Clarity's 107-hp ICE. Both cars have 181-hp motors (but the Accord's motor doesn't use rare-earth elements). Curiously, Honda rates the total horsepower for both cars at 212 hp. Honda never explains how they come up with the total horsepower ratings for their i-MMD hybrids, to my great consternation.
    Last edited: Nov 29, 2019
  17. Geor99

    Geor99 Active Member

    I try to stay in ev mode when going up hills and hv charge to try to get back the battery juice when going downhill or on flat road.

    Like others have said, it will quickly drain your battery going 80 uphill, so it may not work on a length uphill drive.

    The engine struggling noise is disconcerting, but it is what it is.

    No car is perfect.
    Walt R likes this.
    1. Using EV mode up hill KILLS EV range. I’ve observed 3 miles of range depleted per mile going up hill. 30mph, 40mph, 50mph, doesn’t matter. It kills range. Use HV up hill. Use EV down hill.
    Why waste gas going down hill?
  18. ClarityBill

    ClarityBill Active Member

    If the engine was shut off, my trick is not working for you.

    This is for when you are driving in HV, and the rpm's are higher than gear mode. Engine already running, and does not stop. Push the button twice, the engine will keep running, and go to gear mode.
  19. insightman

    insightman Well-Known Member

    Sorry, I meant I'd switch HV off, the Engine would shut off, I'd switch HV on again 2 seconds later and the engine restarted, but not in "gear mode." The 5th time I did it, the engine restarted and I was in "gear mode."

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