Why is my MPG so low?

JCH

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So I recently started tracking and manually calculating my mpg rather than basing it off the trip computer in the car. My most recent fill-up was 10.155 gallons at $3.47/gal. Car drove about 209 miles, and I filled up the car once the computer showed 25 miles remaining. Already sounds crazy without having to calculate the mpg. (basic math 209/10.155 = 20.6 mpg.) I'm not a terrible driver, I rarely go above 3k rpm and I go real easy on the gas and brake. I do drive city the majority of the time, like about 70% and 30% highway, but even then I shouldn't see my mpg this low, right? Everyone who has driven my car is always shocked about how quickly gas is used up despite not driving roughly.

Anyone know if this is normal, or if I should check something? I have a 2018 Civic EX. (2.0L)
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I notice lots of people spend a lot more time idling in their car.. they start it.. pull out their phone and check social media/emails etc.. then 5-10 minutes later pull away. Same thing with folks sitting in their cars at lunch time.. idling.. listening to music. etc. Driving style also impacts fuel economy. Tire pressure impacts fuel economy.
How new is the car? there is a break-in period that impacts efficiency as well.

Your mileage does sound low, i agree, but there must be more to it.
 
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JCH

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I notice lots of people spend a lot more time idling in their car.. they start it.. pull out their phone and check social media/emails etc.. then 5-10 minutes later pull away. Same thing with folks sitting in their cars at lunch time.. idling.. listening to music. etc. Driving style also impacts fuel economy. Tire pressure impacts fuel economy.
How new is the car? there is a break-in period that impacts efficiency as well.

Your mileage does sound low, i agree, but there must be more to it.
Thank you for your input! Usually I start driving as soon as I get in the car because when idling I do notice the mpg numbers start to drop. If I ever idle I usually do it with the car off or rarely, in accessory mode.

The last I checked tire pressure was 32psi on all four. [Actual Measured Tire Pressures (PSI): LF-32, RF-32, LR-32, RR-32.]

I've had the car since February of this year and already had it's first oil change at 3.7k miles in June because the maintenance minder was already at 10% at the time. <-- This seems outrageous too but oh well I followed the maintenance minder
 


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I've had the car since February of this year and already had it's first oil change at 3.7k miles in June because the maintenance minder was already at 10% at the time. <-- This seems outrageous too but oh well I followed the maintenance minder
You're definitely right to be questioning both the fast drop of the maintenance minder and the low fuel mileage. The fact that both of these things are happening makes me think there's something else at play here.

Is it possible that most or all of your driving is short trips? Cars consume the highest MPG, and also cause themselves the most wear, when 'cold' and warming up. The maintenance minder doesn't just look at mileage and time to determine when maintenance is required, it also looks at driving characteristics. If your vehicle rarely reaches fully warmed up (temperature gauge on the left roughly in the middle), this could be the cause of your experience.
 
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JCH

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You're definitely right to be questioning both the fast drop of the maintenance minder and the low fuel mileage. The fact that both of these things are happening makes me think there's something else at play here.

Is it possible that most or all of your driving is short trips? Cars consume the highest MPG, and also cause themselves the most wear, when 'cold' and warming up. The maintenance minder doesn't just look at mileage and time to determine when maintenance is required, it also looks at driving characteristics. If your vehicle rarely reaches fully warmed up (temperature gauge on the left roughly in the middle), this could be the cause of your experience.
During the weekdays I think my trips are roughly around 15 minutes shortest to 25 minutes city driving with about 2-3 times/day. On the weekends however, I tend to drive a bit longer each trip at about 25-35 minutes (highway driving). Usually the temp. is always a bit less than half or at the halfway point on the gauge.

Honda Civic 10th gen Why is my MPG so low? IMG_1330.JPG
 

daPyr0x

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Try asking your dealer? I'm sure they can see more in the vehicle history that might explain it.

15 minutes of low speed/stop&go driving isn't going to warm up everything in the engine bay, but a weekly highway drive should balance it out a bit. Not sure what else to suggest.
 

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What did you get for fuel economy in your previous vehicle?
 

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Back when I had a '16 LX I did majority (90%) city driving and was getting 28-30 mpg consistently. Would drive immediately after getting in and didn't sit in car idling. Work commute was about 25 min each way.

What you're calculating seems low to me.

I am definitely digging the increase MPG with the 1.5T engine even with some more spirited driving.
 
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Your mileage does seem a bit low but the thing that kills both mileage and oil life is short urban trips.

I have the same engine as you do and my Maintenance Minder was down to 5% after fewer than 1500 miles. Most of my driving is short urban trips about 10 minutes. Your Maintenance Minder counts down more based on the number of cold starts that you do, not how many miles you drive. If you are doing two or three short urban trips a day, you will get poor mileage and poor oil life. I average about 20-25 mpg city for short urban trips and about 40 mpg highway.

There are a lot of people who brag on the internet that they get 35 or 40 mpg in the city in the CivicX. Don't believe it. Any gasoline car gets significantly worse mileage in stop and go than it does cruising on the highway at a fixed speed. Watch that bar graph on your dash that shows fuel consumption and you will see what I mean. Whenever you accelerate your fuel consumption skyrockets. And short trips makes that mileage even worse as it takes more gas to start and warm up the car compared to what you get once it is warmed up.

I don't think that there is anything wrong with your car. I believe that it is just the type of driving that you do. To make sure that there is nothing wrong with your car, take it on a longer highway trip and calculate the mileage. If it is around 40 mpg, there is nothing wrong with your car.
 

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So I recently started tracking and manually calculating my mpg rather than basing it off the trip computer in the car. My most recent fill-up was 10.155 gallons at $3.47/gal. Car drove about 209 miles, and I filled up the car once the computer showed 25 miles remaining. Already sounds crazy without having to calculate the mpg. (basic math 209/10.155 = 20.6 mpg.) I'm not a terrible driver, I rarely go above 3k rpm and I go real easy on the gas and brake. I do drive city the majority of the time, like about 70% and 30% highway, but even then I shouldn't see my mpg this low, right? Everyone who has driven my car is always shocked about how quickly gas is used up despite not driving roughly.

Anyone know if this is normal, or if I should check something? I have a 2018 Civic EX. (2.0L)
I started driving s Si 2018 coming from a 2015 Lx (averaged 30mpg+). I was tripping the fuck out when i was getting 25mpg and trying to increase it... yes i drive streets to work not the highway. But i found 25mpg to be extraordinarily low compared to others.

1 tip is all it took...
Someone on here said stop using gears to downshift and slow down. Hold in the clutch or shift to neutral when you see a stop coming up. BOOOOM!

Instantly jumped my 2018 Si to 30mpg pn the streets. And when im driving "spirited" i get 28mpg now on the same streets to work.
 

fiend busa

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I started driving s Si 2018 coming from a 2015 Lx (averaged 30mpg+). I was tripping the fuck out when i was getting 25mpg and trying to increase it... yes i drive streets to work not the highway. But i found 25mpg to be extraordinarily low compared to others.

1 tip is all it took...
Someone on here said stop using gears to downshift and slow down. Hold in the clutch or shift to neutral when you see a stop coming up. BOOOOM!

Instantly jumped my 2018 Si to 30mpg pn the streets. And when im driving "spirited" i get 28mpg now on the same streets to work.
I shudder at the suggestion,

I personally would never do that to save 5mpg lol
 

RobXsi

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I shudder at the suggestion,

I personally would never do that to save 5mpg lol
You "shudder" at using brakes (60$) over wear and tear of you Downshifting and riding out gears to slow down? Hmm interesting

From 25mpg to 30mpg, thats a 15-20% difference in gas savings. Which is quite large mathematically speaking.
 

caspar21

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i get 35-40 mpg regularly. BUT i am 95% hyway right now. if i do the short term mpg it is very bad in town. like what you're reporting.
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