New 2025 Honda Civic Hybrid Sport - Best Practices Q&A

[Mescale2025]

I bought a new 2025 Honda Civic Sport Hybrid.
Area of use is PA & NJ (thus not the frigid northern climates).

A few questions:

1. Oil - Any benefit of using the heavier oil 5W20 (vs. 0w20) in the late spring, summer, early fall?
2. Fuel - Any benefit of running E15 (88 octane) gas in it (occasionally or always)? Would E15 be a good match for it since it's a new Hybrid.
3. 12V FLA Battery – Any benefit of adding a de-sulfation additive (such as Charge-It brand) to it now? Any benefit of adding an anti-shock/vibe mat below it help protect/prolong its life? OEM battery 51R has the removable caps on top.

Any other tips, suggestions much appreciated.

 

[dnewton3]

1) practically none that your engine would experience; you're splitting hairs
2) if your car is rated for E85, then do what you want. If not rated for E85, then the limit is likely E10. Check your owner's manual!
3) dunno

 

[andrew_j]

1)Use oil they recommend for powertrain warranty period.
2) not sure
3) not worth it

Enjoy your car

 

[rijndael]

2) if your car is rated for E85, then do what you want. If not rated for E85, then the limit is likely E10. Check your owner's manual!

 

[twX]

Direct injection engines will get a significant octane boost from ethanol that isn't reflected in the octane number at the pump. I'd use 87 E10 over 87 E0 for this reason. I wouldn't go out of my way to use 88 E15 instead of 87 E10, and I wouldn't pay more for it. The additional knock resistance probably won't make much of a difference.

Higher ethanol content can have negative effects on fuel economy, fuel dilution, and reliability of cold starting.

 

[wemay]

Direct injection engines will get a significant octane boost from ethanol that isn't reflected in the octane number at the pump. I'd use 87 E10 over 87 E0 for this reason. I wouldn't go out of my way to use 88 E15 instead of 87 E10, and I wouldn't pay more for it. The additional knock resistance probably won't make much of a difference.

Higher ethanol content can have negative effects on fuel economy, fuel dilution, and reliability of cold starting.

Aren't both....87 octane?

 

[twX]

Aren't both....87 octane?

Yes, but only because octane ratings are based on tests using PFI engines. GDI engines benefit more from the cooling effect of ethanol, since it's injected directly into the cylinder.

So for a GDI engine, 87 E10 will provide better knock resistance than 87 E0 even though the octane rating is the same, while for PFI engine there will be little to no difference. In my experience, tuning a TGDI engine with different fuels, 87 E10 performs almost as well as 91 E0, while 94 E10 performs far better than 91 E0.

 

[meep]

Not sure of the engine in yours, but our 1.5T had some oil dilution when new, so changing the oil at 5000 miles was good practice, and then we started using a little 5-30 in the 0-20 (same brand oil) to build it up a little.

Do not add anything to the battery. At all. If you can even get the lid off. Those additives give a dying battery 2 more weeks and then they are done.

Enjoy the car!! Driving dynamics of the civic are superb, and I’ll bet in hybrid form it will have remarkable throttle response in addition to excellent mpg!

 

[odie]

Keep us updated on gas mileage . Enjoy !

 

[Marcozi]

To take care of oil dilution take the car on a 30 mile+ trip on the highway on a weekly basis. This boils off the fuel in the oil.

 

[odie]

There's a new review for the '25 Civic hybrid at the AUTOBYTEL website . Very informative .