[mpg_numbers_guy]

If you don't brake enough to get regen, and you aren't stopping the assist through a clutch mod or disabling/removing the battery, your car will almost always be in forced regen mode, which can cost you anywhere from 10-25 MPG in my experience. Forced charging isn't as subtle in the Insight as it is in the Prius.

Have you been able to detect lean burn yet? The IMA will almost always be assisting when not in lean burn, and doesn't assist when in lean burn.

If you switch off the battery and unplug the two connectors on the BCM, you can drive it without the battery functions and see if removing the forced regen improves your mileage to test without removing the battery. You'll have to key off to EOC since autostop will be gone, and acceleration will be slow until you remove the battery, which helps some.

I'm also trying to sell my hybrid battery as well, but haven't had any great luck yet. Probably because I've listed it a bit too high for now.