2022 Honda Civic Si MPG Fuel Economy real-life test via DailyMotor!

[Mikeygman]

I have owned my 2022 Civic si for two weeks now and have been tracking gas mileage. First tank was 93 octane, Average Fuel display said I averaged 36.3 mpg. True gas mileage after dividing miles driven by gallons added was 31.2 mpg. 2nd tank I put in 87 octane, Average Fuel display said 40.1 mpg, true gas mileage was 35.965 mpg. I reset the trip meter every time I fuel up. I drive 50/50 highway city. Entire mileage for the week was 214.5, of which I ran the AC for 40 miles of that, the rest just the windows down . As you can see that Average fuel digital display for Trip A is way off. I also owned a 2022 civic sport touring hatchback (cvt) (only owned for 3 weeks) got the opportunity to buy an Si and went for it. I really wanted a 6MT. Best gas mileage I got on that car was 35.66 mpg running 87 octane

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[Kyofu]

Why put 87 octane in your Si? As per the owners manual:

Unleaded premium gasoline, pump octane number 91 or higher

Use of a lower octane gasoline can cause occasional metallic knocking noise in the engine and will result in decreased engine performance.

 

[Mikeygman]

Why put 87 octane in your Si? As per the owners manual:

Unleaded premium gasoline, pump octane number 91 or higher

Use of a lower octane gasoline can cause occasional metallic knocking noise in the engine and will result in decreased engine performance.

There are numerous other threads on this forum that have discussed this topic. I did my own research on this. The car will run safely on 87, however 91 is recommended. The car adjusts for the lower octane. One of the Honda service guys where I bought the car has the exact same car and runs 87 for now, said as soon as he starts making mods then he'll have to run higher. Now, as far as performance, Yes, I do see a difference. Seems like it has toned down some but for me I'm ok with that for now.

 

[zeroptzero]

This week's highway trip I seen my fuel economy meter get 4.8 L/100 kms, the lowest I've seen since buying the car, phenomenal. The temps are getting warmer every week and fuel economy is better than ever, maybe I had a tail wind ? Driving 70 mph.

 

[tacthecat]

FYI in Canada lower is better; south of there higher is better.

 

[zeroptzero]

FYI in Canada lower is better; south of there higher is better.

Yes Sir. You also have US mpg's and imperial mpg's, I prefer going by mpg's as I grew up just ahead of the metric system coming into effect in Canada.

 

[Mikeygman]

This week's highway trip I seen my fuel economy meter get 4.8 L/100 kms, the lowest I've seen since buying the car, phenomenal. The temps are getting warmer every week and fuel economy is better than ever, maybe I had a tail wind ? Driving 70 mph.

Wow, that is awesome gas milage. Are you running 87,91, 93? Have you used that same type of octane in the entire life of your car?

 

[zeroptzero]

Wow, that is awesome gas milage. Are you running 87,91, 93? Have you used that same type of octane in the entire life of your car?

I am running 89 octane pretty much all the time. Last week I filled up with 87 by accident so I had to run that for a few days, no issues. I ran 91 octane for the first couple months when I had the car but I did not see any benefit or difference from 89, nothing that I could detect.

 

[Mikeygman]

I am running 89 octane pretty much all the time. Last week I filled up with 87 by accident so I had to run that for a few days, no issues. I ran 91 octane for the first couple months when I had the car but I did not see any benefit or difference from 89, nothing that I could detect.

According to my calculations that is 49 mpg. The gas station I go to only has 87 or 93 only. I'm still below the 600 break-in mileage and haven't been running my car hard at all. I do notice that my digital Avg fuel display varies by 3 mpg when I run the AC. Are you running heat or AC? I wonder what your true MPG is? I've found The Digital Avg Fuel display to be off by 5 or 6 mpg's.

 

[zeroptzero]

According to my calculations that is 49 mpg. The gas station I go to only has 87 or 93 only. I'm still below the 600 break-in mileage and haven't been running my car hard at all. I do notice that my digital Avg fuel display varies by 3 mpg when I run the AC. Are you running heat or AC? I wonder what your true MPG is? I've found The Digital Avg Fuel display to be off by 5 or 6 mpg's.

Yes that is exactly right, as I noted I only used the vehicle fuel meter as a guideline to see trends in my fuel consumption. I think the true number is off, I've heard about 3 mpgs based on what others report, I don't think it is off by 5-6 but I am too lazy to sit down and track it any differently. I am seeing the numbers improve every week as weather is getting hotter and that makes sense, worse fuel economy is in winter, best will be in hot dry summer conditions. I consistently see about 43-45-47 mpgs, the one 49 mpg figure was the highest I've seen yet , not sure it will be consistent at that level all the time. My guess is my true regular and consistent fuel economy is about 45 mpgs.

 

[SusieTheCivicSi]

Not sure what to do. But I do drive normal half the time and the other spirited driving/fun driving. A full tank I’ll get about 270 miles full tank. Just curious if anyone got any pointers on what I can do or additives to use to get it back to 300-400 miles.

 

[tacthecat]

If you're running it 'til the lo-fuel light comes on or put in more than 10.2 gallons then you should get 300++ miles; not so much if you can only put 8 or 9 gallons in.

 

[Illuvium]

There are numerous other threads on this forum that have discussed this topic. I did my own research on this. The car will run safely on 87, however 91 is recommended. The car adjusts for the lower octane. One of the Honda service guys where I bought the car has the exact same car and runs 87 for now, said as soon as he starts making mods then he'll have to run higher. Now, as far as performance, Yes, I do see a difference. Seems like it has toned down some but for me I'm ok with that for now.

Hey this is your Si you are taking about? still running 87? my only concern is any long term extra wear and tear vs running 91...tough to get straight answers. I will be driving mine hard

 

[captainscott60]

My MPG on my 22 SI was over 40 MPG on the Highway. It was phenomenal. Best part of the car. That was with OEM Stock F1 all season Tires. My Type R is not even close. Getting about 24 MPG. But the car is new. Hopefully it will get better?

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