Calculated mileage vs. reported at high MPG
 

Since learning about EV-glide mode, I've been getting much better mileage than my pre-EV era. There's always been a little discrepancy between what my car indicates is my gas mileage and what the calculations indicate based on how much gas & put in. However, I've noticed that when I was getting 44-46mpg, the 2 numbers were much closer together. I just filled up after getting a 51.3mpg @ 540.5 miles according to the car. But when I calculate mpg based on how much gas I put in, it comes out to 52.6! I've been very careful to always use the exact same pump, and now that I've had 3 500+ mile tanks in a row, I've noticed this big discrepancy on all 3 tanks. Anyone else notice this?

Re: Calculated mileage vs. reported at high MPG
 

Yep. That is a well known issue. The HCH-2 estimates the displayed FE rather conservatively. Many of us have reported mileage differences amounting to 2 mpg or more.

Cheers;

MSantos

Re: Calculated mileage vs. reported at high MPG
 

Same here. I'm always in the 1.5 - 2.0 mpg error range. It's just my little "present" that I look forward to when I'm getting a bad tank!

Re: Calculated mileage vs. reported at high MPG
 

My MPG calculated-at-the-pump averages 1.4 MPG better than my dash MPG on my 2006 HCH2.
This is over a year, or 20 tanks.

Re: Calculated mileage vs. reported at high MPG
 

Amazing stats Kenny! :) Thanks for all the replies. I can imagine the process of calculating exact mileage is pretty much an educated estimate, but not much better than that. I'm just happy it's actualy better than reported instead of the other way around.

...back to figuring out how to mount a sail on the roof :)

Re: Calculated mileage vs. reported at high MPG
 

Don't forget to multiply your MPG by about .97 to compensate for the inaccurate odometer that Honda gave you. Use a hand-held GPS on your dash board, take trip down the freeway, and compare to see what I mean. Your HCHII reading will say you've gone farther and faster than you really did to the tune of 3%. Honda's already been sued for doing this on the Odyssey as owners rightfully pointed out that the 36,000 mile warranty should be extended by the error.

Re: Calculated mileage vs. reported at high MPG
 

Can anyone provide any more information on the inaccurate odometer issue and what it means to our car and warranty?

Re: Calculated mileage vs. reported at high MPG
 

Here's an earlier discussion on this board titled: Odometer Error = Lower Real MPG

I don't know if the board allows links, but here's a link to it: https://www.greenhybrid.com/discuss/...ad.php?t=11189

Also Google: honda odometer class action

And you'll see lots of information.

Re: Calculated mileage vs. reported at high MPG
 

I actually just got that letter about a month ago re: our Odyssey. I'm glad, since we went over our lease mileage to the tune of $1200. The letter says if we've already turned it in, then Honda Lease will automatically send us our refund once the lawsuit is settled in May. I'll drink an oilchange if that actually happens :).

Thanks for the tip re: the GPS. I'll have to give that a try.

My 07 HCH II odometer is dead on!
 

The nice thing about having navigation on the HCHII is that you can go into the diagnostics screens on the Navi to look at the GPS computed speed (to a 1/10th of a mile per hour) vs. the speedometer display.

On my car with the slightly taller 16" tires and rims, the 2 are exactly in sync with each other. I also tested with a handheld GPS to confirm these findings.

It would be interesting to see if a HCHII with 15" tires has the same result.