so my 2009 civic hybrid with 59k miles only gets around 35 mpg no matter what I do. I have new 0w20 Mobil one oil change, cvt fluid changed, tires are good and at 38 psi, new 12 volt battery. I drive slow and use cruise control as much as possible in city and highway. No matter what I do I can't seem to even reach 38 mpg. Even with ac off in the morning it still cannot reach the average reported by lost folks. I do see fluctuations in ima charge several times when I drive the car. I set cruise to 60-62 mph on highways and that helps bring it up to 37 mpg but that's about it. Anything I should inspect?

 

Your hybrid battery is severely deteriorated.

The IMA SoC gauge behavior you are observing is recalibrations. They kill mileage. Unfortunately, the revised battery management can cause this to continue for a very long period of time.


A negative recal occurs at 0;25 the moment assist is given. Gauge "marches" down at 1 bar per second to 2 bars with forced charging.

A positive recal occurs at 0:42 where charging stops, and the gauge "marches" at 1 bar per second to 8 bars.

This is a sign of a severely imbalanced battery.

Start documenting each and every recalibration (if you see only 2 of 8 bars, you're almost certainly in a recalibration). Document your gas mileage, speeds, and driving style.

Contact Honda corporate and describe this behavior.

ALL 09-11 HCH2 had their battery warranty extended to 10yr, 150K miles in ALL STATES.

 

Keith,
im the second owner and original owner had the ima pack replaced under warranty overseas in 2013. Does that mean I'm out of luck or does the warranty still applies?

 

If it's a US car, it should be covered.