My Insight does show l/100 km, and I wish it didn't.
As it shows only 1 digit beyond the point, and it becomes less precise with better FE. When the number gets lower that feels like an accomplishment, but even per trip I have to wait so long to see 4.1 go down to 4.0... That is a 2.5% difference. It's just frustrating. It should have 2 digits beyond the point when it has only 1 ahead.
If it did MPGs with one digit beyond the point the steps would be less than 0.2 % when beyond 50.0 mpg...
Nevertheless I'm happy with my indicated average of 4.1 l/100 km since the last fill (3 2-way commutes and a shopping at about freezing temps, total of 225 km) Car and steering wheel nut are improving rapidly
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2011 Honda Insight + HID, LEDs, tiny PV panel, extra brake pad return springs, neutral wheel alignment, 44/42 PSI (air), PHEV light (inop), tightened wheel nut.
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lifetime FE over 0.2 Gigameter or 0.13 Megamile.
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For confirmation go to people just like you.
For education go to people unlike yourself.