Beyond the already noted difference in tank types (plastic 13.2 vs metal 12.3), it might also be that Honda only measures the tank itself, but leaves the fuel line between the tank and the injector out (half-gallon, maybe?), as well as the line between tank and gas cap (probably another gallon-plus).

 

And some of us (well, at least Mr. Kite and myself that I remember) have owners manuals that state 12.4 gallons for our 2006 HCH2s.

 

Kenny, seriously, man, wtf. I'm convinced you have mounted a sail on the HCH... a mizzenmast from a tow-hitch, perhaps ?

 

I filled up again today (12 days since last fillup). The fuel warning light came on at 492, and the last light went out at 525. I ended up at 618 miles with 50.2 mpg. Yippee - my 2nd 600+ tank! When I filled up, first click was at 12.2 gal. I then topped off to 12.3 gal (brought it up to 38.00). So either I was about ready to be running on electric only, or there was more in there! Can't say cause I didn't have a gas can in the car and didn't want to push it any further. I only top off to the nearest .50 cents so I don't overfill the tank. So did I really drain the tank to fumes or do I have the 13.2 gallon tank? I may run the next tank till I'm on electric only and carry a gas can with 1 gallon in it.

 

Honda manual discourages running the gas tank empty - engine may backfire etc... It also reccomends only filling to first auto click.

To me, shooting for 50, 60 70 mpg versus 600+ mile tanks should be the real goal.

I refilled recently only 6 gal - at a good price, for 364 miles - so I was happy about the 62mpg+.

 

Also gas is heavy.

We hypermilers try to get extra weight out of our trunks.
But we have no hesitation about filling up our gas tanks and burning more gas to carry around all that extra weight.

I don't do it, but I'd understand if someone never filled their tank over half full for this reason.

 

I have an even better idea for improving fuel economy.
https://www.greenhybrid.com/discuss/...earchid=160005