ICE mileage

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JKroll

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Drove second time on highway but first time keeping records.

Drove 384 miles to chicago. Avoided using battery so drove in HV mode. Still battery drained from EV charge of 35 to about 20. So in HV mode still drained battery 15 EV miles.

ICE is little noisy but no problems reaching 80-90 mph.

The mileage I got on ICE was 38.85

I was under impression that its 55 with atkinson cycle etc. What am I missing?

Not impressed.
 
The longest drive that I have made with my Clarity was a trip from Florida to Ohio and back last summer. The total trip distance was 2032.2 miles. I fueled a total of 8 times and used 45.8 gallons. Overall mileage was 44.4 mpg. If I subtract out the approximately 50 miles that were driven in EV mode, the gasoline mileage was still a respectable 43.3 mpg.
 
1. The Clarity is rated at 44/40 city/hwy mpg, though some of us exceed that marginally. This month, I've been getting ≈41-45 mpg in 80% hwy driving at 65-75 mph. If the dealership told you to expect 55 mpg, they might have been getting the Clarity confused with the Insight.
https://fueleconomy.gov/feg/Find.do?action=sbs&id=41183&id=40351

2. If you're driving 90 mph in Illinois... please be very careful. Exceeding the posted limit by 26 mph is a Class B Misdemeanor. [625 ILCS 5/11-601.5(a)]

3. Driving over 75 mph can really affect your mileage. To trivialize some equations, drag force increases mostly with the square of the velocity -- increasing your speed from 70 mph to 80 mph will increase your drag force by (80²-70²)/70²≈30%. So if you're getting 45 mpg @70 mph, you might get 45/1.3≈35 mpg @80 mph.
http://hyperphysics.phy-astr.gsu.edu/hbase/airfri.html
http://www.mpgforspeed.com/

4. Good hybrids are temperature sensitive, just like BEVs, since they don't have much waste heat to spare. It looks like the average temperature near Chicago this weekend was 37°F, which counts as pretty chilly for an engine. Looking at other hybrid mileage data, this should incur a ≈15% mileage penalty compared with its spring/fall maximum @65°F.
https://www.reddit.com/r/dataisbeau...ars_in_a_toyota_prius_v_fuel_efficiencymigal/
http://enerjazz.com/prius/

5. Driving personality also makes a big difference. When my wife drives, she's been averaging around 38 mpg this month.


In summary: Your Mileage May Vary. Wait until things warm up a little before making any conclusions on your mileage. In the meantime, try to drive like you have an open thermos of coffee in your lap.
 
My old ride advertised 27 MPG highway (4cyl 2003 Outback). I measured actual mileage in between about 18-22. My goal with the new car was something that did 40 or better. My own experience measured from actual miles (not using Clarity's trip computer) has exceeded 40 MPG on the highway even when I have periods of my drive around 80mph. Anyway, getting the rated 40mpg.

Note that with hybrids the small number is highway number. i.e. while clarity advertises 44mpg that's for in-town stop and go driving only. Highway is 40 mpg. i.e. all hybrids AFAIK do better in-town due to regeneration on breaking.
 
The best HV mileage I've gotten is 52 mpg (after subtracting out the EV miles lost during the drive) on two separate 200 mile loops. These were rural roads where my speeds stayed between 50-60 mph. The mileage was calculated with the gasoline used from actual fill ups, not the car's computer. On a road trip, I got about 48 mpg but I stayed within speed limits, which never exceeded 65 mph. Others have reported getting about 40 mpg going 75-80 mph, which is amazing for a 2 ton car. Speed kills fuel efficiency.
 
MNSteve said:
I cannot find any published number that is close to 55 mpg. Can you point us to where that's documented?
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In the current Consumer Reports auto issue, they reported that the Insight hybrid is their fuel efficiency champ with 54 mpg in their testing which is 2 mpg better than the Prius they tested. The Insight has the same 1.5 litre engine as the Clarity but is much lighter and the battery is a tenth the size. It's pretty amazing that the Clarity can still get such great HV mileage given it's size and weight.
 
PHEV Newbie said:
In the current Consumer Reports auto issue, they reported that the Insight hybrid is their fuel efficiency champ with 54 mpg in their testing which is 2 mpg better than the Prius they tested. The Insight has the same 1.5 litre engine as the Clarity but is much lighter and the battery is a tenth the size. It's pretty amazing that the Clarity can still get such great HV mileage given it's size and weight.
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I agree. But the OP was "not impressed" the his Clarity was getting less than 55 mpg and I'm curious why he expected that mileage.
 
Thanks for everyone's concern regarding speed. I am not a very fast driver so chill. The speed limit is 70 here so I was mostly in 70-75 range.
But I did try going around 80 in some patches.
I have only one ticket on my old CRV driving at 45 in 35 mile zone. Funny thing is I rarely drove this car fast since it was big and not very sleek for quick acceleration.

Cold weather would have some effect . Also my tire pressure were low .. indicator came on after we completed the trip. It was around 32 in all tires.

The 55 I saw was in earlier reviews etc. Maybe that included using the EV mode. I avoided using the EV mode since I wanted to have a ICE mileage number.

If accord gives 38 on highway what would be clarity's advantage.
 
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JKroll said:
If accord gives 38 on highway what would be clarity's advantage.
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There is no advantage to Clarity for long highway trips. The Clarity advantage comes from using zero fuel around town with trips under 50 miles.

On long highway runs it’s just another car that gets about 40mpg, and it never promised to be anything but that. 40 hwy is also the EPA rating.
 
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Dan Albrich said:
Note that with hybrids the small number is highway number.
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My Insight was rated 70 mpg highway/61 mpg city back when it was new. The EPA has since lowered the those numbers to conform with updated testing protocols, but my point is that Honda's old-gen IMA hybrids achieved greater highway mileage than city mileage.

I believe all modern hybrids get better city mileage than highway mileage, however. Regardless of the updated EPA testing protocols, I still see > 70 mpg in warm weather.
 
JKroll said:
Drove second time on highway but first time keeping records.

Drove 384 miles to chicago. Avoided using battery so drove in HV mode. Still battery drained from EV charge of 35 to about 20. So in HV mode still drained battery 15 EV miles.

ICE is little noisy but no problems reaching 80-90 mph.

The mileage I got on ICE was 38.85

I was under impression that its 55 with atkinson cycle etc. What am I missing?

Not impressed.
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JKroll

Here is the link to another thread on HV mode mileage from several months ago.

https://insideevsforum.com/community/index.php?threads/hv-only-gas-mileage.4089/

Hope this helps.
 
On relatively flat roads and driving around 55 mph average speed (2 lane roads here in a lot of rural areas), I've got about 50 mpg pretty consistently.
 
Your mileage may vary: I have found the gear mode gives dramatically better mpg. I have also found gear mode is a little more elusive when temperature is below 40F (worse below 20F). I normally drive 73 mph, and don't go over 75 mph. In colder temperatures, I need to keep battery below 30% mileage. I can get it to go back into gear mode by switching out of HV mode, and back in (two button clicks, about a second apart).

It is a different car as the temperature is warming up. The temperatures here were above 50F, and my EV range jumped to 41, from 28 on the previous charge.

When driving, it appears charging control works on actual percent of battery, so cold temperatures have lower total battery capacity, and the controller is working over a smaller real charge. The control dumps out of gear mode when the charge drops too much below target, and the range is smaller in cold temperatures.

Since I don't drive the faster speeds normally (but expect to in the future), I would love to have a conversation with someone with experiences of gear mode at higher speeds: What is the maximum speed that gear mode will engage? How much charge loss kicks it out of gear mode?
 
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ClarityBill said:
I have found the gear mode gives dramatically better mpg
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If Engine drive mode didn't provide better gas mileage than Hybrid drive mode, Honda never would have included that somewhat complex and weight-increasing mechanism. That fact completely backs up your impression.
 
If the engine was 'noisy', I would guess it was not gear mode (Engine drive). At 73 mph, my engine gets 'noisy' when it dumps out of gear mode. Keeping it in gear mode will give better gas mileage.

To get better gas mileage, manage the car. (Dance with the partner you got.)

It looks like he went to HV mode with a fully charged battery: At cold temperatures, it has trouble staying in gear mode with a full battery. I'm not sure what it does at warmer temperatures, but the fact that it lost charge, and raced the engine, sounds like it could not get back to target charge. In this case, managing the car would wait till you lost a little charge before switching to HV. IMHO, this would not be a big change.

If you want to just let the car do it what it wants, you will get 'good' mileage.
 
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ClarityBill - this is interesting take "It looks like he went to HV mode with a fully charged battery: At cold temperatures, it has trouble staying in gear mode with a full battery."

I dont know what gear mode is. So you are saying I should have started in EV mode and let the car do what it wants rather than having a full battery and forcing it to run ICE engine with HV.

On next trip I will try that. I wanted to get a mileage for ICE engine and all of you are saying this is not the right way to do it ?
And almost all of you have got better mileage than me.

I am going to read up some other threads on this forum.
 
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