[donvnielsen]

My latest update is positive, much more than my previous. The Civic is at 4,300 total miles, now. Just did 200 mi highway driving, 70mph, in sport mode, with temperatures at 35-37f. Achieved 45mpg, which is a bullseye on expectations. I am happy.

I have emphasized Sport Mode because this is the first I have engaged it. In sport mode I observed continuous engine engagement and no battery engagement at all at 70mph. In Normal mode I observe it constantly switching between battery and engine. Yes, at 70mpg. It was my understanding that engine-transmission lockup occurs at 62mph. I do not recall driving mode was being mentioned as a criteria. I will have to read the owners manual, again, because I do not recall it ever mentioning lockup in the manual.

Other observations...we were switching on and off the heat to the car. I did not see anything observable in Sport Mode.

I am happy to see highway mpg within expectations. I'm expecting my city mpg is going to come up to expectations when temperatures get above 50f where the battery will be more in a comfort zone.

 

[donvnielsen]

As I have posted on numerous occasions I am getting very close to the published figures. I bought my Sport touring sedan in August and now have just under 9,000 miles. Prior to the onset of winter my lifetime average was 48.7 mpg but has since fallen to 47.6 mpg. I would add that I am also now carrying around a spare tire which I would guess weighs maybe near 50 lbs (I didn't actually weigh it) and that I am in California so winter has been very mild. In my opinion the biggest factor is most likely extreme cold weather which is something I have not had to deal with.

Interesting comment about the spare. I was thinking of doing the same thing. I just don't want to lose the trunk space. When you say spare, do you mean those lightweight short-haul spares, or a full tire? Thanks, dvn

 

[donvnielsen]

For the consistent 75 mph highway driving you describe, the 38 mpg is what I would expect. You are constantly using a 2 Liter gas engine for your propulsion in this scenario - you are NOT driving a hybrid. So the 38 mpg is what I would expect from an efficient Honda gas engine. In a similar scenario, I get about 40 mph in my 1.5 Liter Honda FIT.

But, you can look forward to 45 to 50 mpg when driving on slower two lane highways and around town!!

I posted an update to my situation. One observation that I made last night was that engine-wheel lockup was only happening in Sport Mode. In Sport Mode there was no observable input from the battery at 70mph...looking at the power display. Switch to Normal Mode and it constantly switched between EV, battery input, and battery charge. Not sure if it is supposed to be doing that in Normal Mode as it was my understanding that it would lockup at 62 mph, no driving mode mentioned.

 

[donvnielsen]

On a 1,600 round trip mini vacation.
The first leg driven in two segments - 500 miles and 275 miles. 90% of the distance was on I95/I4 driving at +5 over the limit = 70 -75.
Two quick stops to change drivers and top off in first 500.
One stop to change drivers and top off in the last 275.
A good portion was in the "Smart" drive mode. About 200 miles in the "ECON" mode.
No weather or trafic issues to disturb the calculation.
We achieved only 38.5 mpg after we reached our destination.
Trip computer is accurate - I checked the mpg manually after the first two top offs.
Far below the expected 45+.

I'll stay in ECON on the two day return trip.

Try Sport Mode on the highway and watch the power display. Do another 200 mi and post and update. What do you observe?

 

[donvnielsen]

As you state octane is important to prevent engine knocking. It generally will have zero difference in mileage unless your engine is knocking because the octane is too low. At least that's what my mechanic friend tells me lol.

Switching to no-alcohol gas will help a couple mpg but does not compensate for extra cost. One could factor in the anecdotal "no-alcohol gas will avoid future problem", but I am not aware of any hardened proof of that.

 

[pi.actual]

Interesting comment about the spare. I was thinking of doing the same thing. I just don't want to lose the trunk space. When you say spare, do you mean those lightweight short-haul spares, or a full tire? Thanks, dvn

Not a "full sized" spare, I don't think anyone has had one of those for decades. It fits in the well and doesn't take up any trunk space but it is my understanding this is only true for the sedan so not an option if you have a hatchback.

 

[kart17]

My latest update is positive, much more than my previous. The Civic is at 4,300 total miles, now. Just did 200 mi highway driving, 70mph, in sport mode, with temperatures at 35-37f. Achieved 45mpg, which is a bullseye on expectations. I am happy.

I have emphasized Sport Mode because this is the first I have engaged it. In sport mode I observed continuous engine engagement and no battery engagement at all at 70mph. In Normal mode I observe it constantly switching between battery and engine. Yes, at 70mpg. It was my understanding that engine-transmission lockup occurs at 62mph. I do not recall driving mode was being mentioned as a criteria. I will have to read the owners manual, again, because I do not recall it ever mentioning lockup in the manual.

Other observations...we were switching on and off the heat to the car. I did not see anything observable in Sport Mode.

I am happy to see highway mpg within expectations. I'm expecting my city mpg is going to come up to expectations when temperatures get above 50f where the battery will be more in a comfort zone.

Noticed that driving this morning. Less switching but at slower speeds 45-50 mph average. 30F /-1 C or so. I think the normal mode cal is too aggressive with hunting pure ev and dumping the battery. No having to mess with the heat either I was around 41-42 maybe but my drive is about 13miles..

 

[mtaxter]

Try Sport Mode on the highway and watch the power display. Do another 200 mi and post and update. What do you observe?

I did what I said I would. I just finished the drive from Orlando to Savannah. Perfect weather. No wind. Tires set at .5 over. Constant cruise control a few mph over the limit. One gas stop - 87 octane. Two drivers - one did 140 miles and the other did
Two drivers. Driver A did 145 miles at about 70 mph and Driver B did 150 miles at 70 mph.
295 miles achieved 41.6 mpg set on ECON.
We then did another 20 miles at slow local neighborhood speed - maybe 25 mph - raised the total after 315 miles to 42.3 mpg.
I am a bit more staisfied with about a 3mpg improvement at the ECON setting. The only material difference. Could the car have been modestly lighter? I had to put about 8.8 gallons of gas in at the refuel stop.
I have 500 miles to drive tomorrow; 450 on I95 at 70+/- mph and 50 on local roads at 55 mph.

 

[mtaxter]

I did what I said I would. I just finished the drive from Orlando to Savannah. Perfect weather. No wind. Tires set at .5 over. Constant cruise control a few mph over the limit. One gas stop - 87 octane. Two drivers - one did 140 miles and the other did
Two drivers. Driver A did 145 miles at about 70 mph and Driver B did 150 miles at 70 mph.
295 miles achieved 41.6 mpg set on ECON.
We then did another 20 miles at slow local neighborhood speed - maybe 25 mph - raised the total after 315 miles to 42.3 mpg.
I am a bit more staisfied with about a 3mpg improvement at the ECON setting. The only material difference. Could the car have been modestly lighter? I had to put about 8.8 gallons of gas in at the refuel stop.
I have 500 miles to drive tomorrow; 450 on I95 at 70+/- mph and 50 on local roads at 55 mph.

Day two of return trip from Savannah to Williamsburg.
Three driving segments Driver A, B and A again.
Perfect weather. No I 95 traffic jams.
Set on ECON all day.
425 miles on I95 at about 72mhp average with times at 75-80 to pass.
Last 53 miles on country roads at 55 mph.
Overall mileage was 44.3mpg.

It is worth having a discussion about SPORT and NORMAL modes and how they influence mpg. There has to be some obvious differences.

 

[Maddman]

I’ve come to accept the degradation of MPG at highway speeds especially as the temps have dropped. It seems to drop 2-3 MPG or so every 10 degrees below 60*. My recent MPG was about 34 and the avg. temp was in the teens. I average about 75 MPH during my 80 mile daily commute.

That sounds about right. I have always noticed a mileage drop during lower temperatures.

 

[neo8175]

Average now 50.5mpg and at 1900 miles. I drive the same routes everyday to and from work. LIve in NY. Average driving per day is 30-35 miles with 70% highway.

 

[Hatch808]

Switching to no-alcohol gas will help a couple mpg but does not compensate for extra cost. One could factor in the anecdotal "no-alcohol gas will avoid future problem", but I am not aware of any hardened proof of that.

Sorry this is so late but I'm not familiar with the forum notifications.

I know that ethanol is pretty harsh on gas lines and fiberglass tanks as far as boats go. It's also hydroscopic so another reason boaters don't like it. I suppose that could all be bad things for our cars engines as well.

 

[TopOchs]

I have a 2025 civic sport touring hybrid that I purchased on 11/19 (just shy of two weeks ago). Since then I am already going to have to fill up a second time.

it says my average fuel is 44.4mpg but I have only driven 350 miles on the second full tank.

I have also noticed it sometimes takes quite awhile for ev to kick in even in instances when i have full charge and drive steady at 55mph.

i live in California, do mostly city driving with two trips on the highway at 75mph top speed for only 60 miles round trip. I also have been very conscious of my foot, making a concerted effort to drive steady and brake even.

I can clearly tell the readings are off but even if they were accurate id be averaging well under 40mpg which is no better than my 2007 corolla.

just need to know if im overly concerned and if possible, any explanation why filling up a few times increases mileage.

this is mt first new car and first hybrid so i am very inexperienced.

I bought mine in November of '24. I have about 10,000 miles on it now. I live in a relatively hilly area around Pittsburgh PA. At first I got LESS than 40 mpg. I attribute this to cold conditions (heater in use) and break in. Right now I'm getting just under 44 mpg. I drive mostly on highway conditions (60+ mph). I did notice that when I'm in Pittsburgh city itself, the mpg does go up to 52/53 mpg. However, for suburbian driving, I think it's going to end up around 43-44mpg. No where close to the 50+.

 

[Hatch808]

Having been a previous Prius owner (I believe I owned 4), a Honda Insight and now a 2025 Civic hybrid, I don't think I had any unrealistic expectations. I know how to work the hybrid system to give me the best mileage. The only expectation I had was what was claimed on the window sticker, that it has a combined MPG of 49. I would have had no problem with a few miles per gallon less than this in the winter, as that was also what happened in my other vehicles, but 10 and up to 19 MPG less than what is listed on the window sticker is absolutely ridiculous. The last time I was this upset with a vehicle was when I was stupid enough to believe Hundai's claims that the Elantra would get 40 MPG, which was also a lie. I actually got some compensation from them because of that. The only consolation is reading all the posts here that I am not the only one experiencing this, but it seems to me that Honda is probably aware of this. Sounds a lot like false advertising to claim this and not deliver. It shouldn't have to be work to get what they promise from a vehicle.

Well Honda can claim whatever they want but the EPA does the testing to provide the numbers you see on the window sticker.

 

[HaulinAuss]

Now have 2,500 miles on our 2025 Civic Hatchback Sport Touring Hybrid that we purchased in January. Our average is above 45 mpg. Combination of highway/city driving. Temperature has ranged from 10 F to 75 F.

 

[Bluegrass]

Well Honda can claim whatever they want but the EPA does the testing to provide the numbers you see on the window sticker.

This is wrong.
The EPA does NOT "do the testing to provide the numbers on the window sticker".
The actual testing is done by the vehicle manufacturer, supposedly per the EPA's standards.

 

[Bluegrass]

I was getting 40 MPG (hand calculated) during single digit winter weather.
That gradually increased to the low/mid 40's as the weather moderated.

With the current mild weather and no AC usage, I'm getting just over 50 MPG.
I'll be interested to see how using AC will negatively impact fuel economy.

 

[HaulinAuss]

I have a 2025 civic sport touring hybrid that I purchased on 11/19 (just shy of two weeks ago). Since then I am already going to have to fill up a second time.

it says my average fuel is 44.4mpg but I have only driven 350 miles on the second full tank.

I have also noticed it sometimes takes quite awhile for ev to kick in even in instances when i have full charge and drive steady at 55mph.

i live in California, do mostly city driving with two trips on the highway at 75mph top speed for only 60 miles round trip. I also have been very conscious of my foot, making a concerted effort to drive steady and brake even.

I can clearly tell the readings are off but even if they were accurate id be averaging well under 40mpg which is no better than my 2007 corolla.

just need to know if im overly concerned and if possible, any explanation why filling up a few times increases mileage.

this is mt first new car and first hybrid so i am very inexperienced.

Gas tank holds 10.6 gallons. Light may come on with maybe 2 gallons or so left in the tank. How many gallons did it take to refill?

 

[HaulinAuss]

I was getting 40 MPG (hand calculated) during single digit winter weather.
That gradually increased to the low/mid 40's as the weather moderated.

With the current mild weather and no AC usage, I'm getting just over 50 MPG.
I'll be interested to see how using AC will negatively impact fuel economy.

AC usage typically has minimal impact on MPG.

 

[Bluegrass]

AC usage typically has minimal impact on MPG.

AC has minimal impact on MPG in a HYBRID???

The engine need to be running in order for the AC compressor to work.
Therefore, AC is likely to have a similar negative impact on MPG as running the heat in cold weather.