23 civic SI fuel grade question

[Timmyzee]

Hey gang

Spoke with my Honda dealer and they say that the SI is totally fine with using regular 87 gas, won’t void warranty, and states no problems will occur. Would it hurt filling every other tank with 87 and 91 for cost savings ? Thoughts on 89? Here In Canada, 91 octane works out to around 5.09/gallon (1.70/L) and that’s getting it at Costco. Good news is I am getting around 39mpg in sport mode.

Thanks everyone

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[DYI01]

In the owners manual it says CVT models can use 87, manual models need to use 91 minimum.

 

[Timmyzee]

In the owners manual it says CVT models can use 87, manual models need to use 91 minimum.

Thanks for the post. Must be a Canada thing. My fuel door say 87 minimum and 91 preferred. Odd. As does my manual
Too. Again maybe a Canada thing

 

[madbikes]

Thanks for the post. Must be a Canada thing. My fuel door say 87 minimum and 91 preferred. Odd. As does my manual
Too. Again maybe a Canada thing

It's not a Canada thing. USDM Si and Type R says you can use 87 on the fuel door, which will work but not recommended.

Saving a few dollars each time by pumping 87 instead of 91 is not worth it because they are not tuned for that and timing is pulled for doing so, which hurts performance and not good on turbocharged/supercharged engines.

 

[Shankmeyster]

Either use one or the other. Motors don't like having to go back and forth on timing when you continuously switch octanes. Personally I haven't used anything but 91 in all of my turbo Civics.

 

[Timmyzee]

It's not a Canada thing. USDM Si and Type R says you can use 87 on the fuel door, which will work but not recommended.

Saving a few dollars each time by pumping 87 instead of 91 is not worth it because they are not tuned for that and timing is pulled for doing so, which hurts performance and not good on turbocharged/supercharged engines.

Excellent. Thank you !

 

[MYK20C1]

Hey gang

Spoke with my Honda dealer and they say that the SI is totally fine with using regular 87 gas, won’t void warranty, and states no problems will occur. Would it hurt filling every other tank with 87 and 91 for cost savings ? Thoughts on 89? Here In Canada, 91 octane works out to around 5.09/gallon (1.70/L) and that’s getting it at Costco. Good news is I am getting around 39mpg in sport mode.

Thanks everyone

Honda engines are designed and certified to run on regular 87 octane. Peak power may require higher octane but 87 works fine. No worries for everyday driving!

 

[Savannah@TSP]

91+ if you want to take care of the car.

 

[dathoneycomb]

It doesn’t have anything to do with what transmission the car has. It’s usually recommended for “High performance” engines, especially ones with turbos to run premium, but that doesn’t mean the car can’t run on 87. The system will adapt the timing. You will lose a little performance and possibly some fuel efficiency but try it and see. Might be a negligible difference. All that said, I’ve never put less than 91 in my SI or Type R

 

[rui]

It doesn’t have anything to do with what transmission the car has.

It actually does. With the CVT the ECU can control the RPM to avoid pre-detonation. With a manual transmission the driver can induce that condition without the ECU being able to do much about it (e.g., high load, low rpm). Hence why the owners manual states 87 is fine for the auto but not for the manual.

 

[t0rdep]

I have a fl5 type r and had to run 95 instead of the usual 98 or 102 Octane just for reference car worked fine but top speed on the autobahn was massively different 244km to 276 also car pulled back on power massively and felt very lethargic on 95.

 

[dathoneycomb]

With a manual transmission the driver can induce that condition without the ECU being able to do much about it (e.g., high load, low rpm).

Huh, ok makes sense.

 

[rui]

I have a fl5 type r and had to run 95 instead of the usual 98 or 102 Octane just for reference car worked fine but top speed on the autobahn was massively different 244km to 276 also car pulled back on power massively and felt very lethargic on 95.

It surprises me that it affects performance that much. The US-spec car is rated for 315 hp on 91 octane AKI, which is equivalent to the European 95 RON. Meaning, only 14 hp less than the Euro-spec horsepower rating.

 

[t0rdep]

To be honest it could also be down to fuel quality been used to shell ultimate and had to get what I could in the middle of Austria still not a massive difference in normal drive only when pushing hard. The uk spec is down for 325 I believe it felt like it lost more than 10bhp down to fuel

 

[absolude]

Hey gang

Spoke with my Honda dealer and they say that the SI is totally fine with using regular 87 gas, won’t void warranty, and states no problems will occur. Would it hurt filling every other tank with 87 and 91 for cost savings ? Thoughts on 89? Here In Canada, 91 octane works out to around 5.09/gallon (1.70/L) and that’s getting it at Costco. Good news is I am getting around 39mpg in sport mode.

Thanks everyone

Your fuel economy is amazing.
I'm getting 10 litters/100 km. which is 28mpg, in US gallons.
This is in Toronto.

Are you doing a lot of hwy driving?

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