10/24/08 34.06 Pump / 35.8 Nav = 5.10%
11/5/08 34.04 Pump / 35.5 Nav = 4.29%
11/20/08 32.37 Pump / 33.4 Nav = 3.17%
12/4/2008 30.99 Pump / 32.6 Nav = 5.20%
Creeping up on a 4.5% error rate.
Also dont like the way the colder weather has been dropping our FE but I doubt Mother Nature will do anything about that. lol On the bright side, this morning on the 4.7 mile trip home from filling up the gas tank we got 43 MPG!

 

I filled-up today and had a Nav Tank average of 51.8mpg. Gas pumped was 14.01 gallons for 683.9 miles. This only gave me a 48.815mpg gas pumped tank average. I think I squeezed about .4 extra gallons in the tank this fill-up (13.6 gallons) so my tank should have been 50.286mpg. This was what I was estimating before the fill-up. It will all average out in about 15 tanks I think. Here is what I have to date:

9/2/08 46.659 Pumped / 46.4 Nav = -.5%
9/18/08 45.86 Pumped / 47.0 Nav = 2.5%
10/4/08 45.173 Pumped / 47.8 Nav = 5.8%
10/25/08 46.04 Pumped / 47.8 Nav = 3.9%
11/14/08 48.06 Pumped / 50.0 Nav = 4.0%
12/4/08 48.815 Pumped / 51.8 Nav = 6.2%

This brings my total miles to 4658.3 on my '09 FEH with 102.374 gallons burned from start-up at the Factory. This new tank puts my Lifetime MPG at 45.5mpg. As far as the Nav Sys Tank Average display, the 6 percentages above for me added to 22.9%, divided by 6 tanks = 3.816%.

You had only 4 tanks to compare in a row and if you take my last 4 tanks, my average would be much higher also. We both need to continue monitoring the Nav Sys MPG readings for long term results for the group of '09 FEH owners with Nav.

GaryG

 

Just completed my 7th Tank on my '09 FEH and here are the best numbers yet. The Nav Sys had a Tank reading average of 54.1mpg which was 4.45% higher than E10 pumped of 13.552 gallons. This was on a 702 mile tank which gave me a 51.8mpg average using pumped gas calculations. My weather averaged 60 - 80F degrees which was I'm sure far better than the cold weather most are having up North right now. The wind was bad 75% of the time but this new RFS technique was awesome in city driving.

Here is my list of pumped gas VS the Nav Sys readings to date for only the '09 models to compare:

9/2/08 46.659 Pumped / 46.4 Nav = -.5%
9/18/08 45.86 Pumped / 47.0 Nav = 2.5%
10/4/08 45.173 Pumped / 47.8 Nav = 5.8%
10/25/08 46.04 Pumped / 47.8 Nav = 3.9%
11/14/08 48.06 Pumped / 50.0 Nav = 4.0%
12/4/08 48.815 Pumped / 51.8 Nav = 6.2%
12/18/08 51.80 Pumped / 54.1 Nav = 4.45%

This brings my total miles to now to 5,360 on my '09 FEH with 115.926 gallons burned from start-up at the Factory. This new tank puts my Lifetime MPG at 46.236mpg. As far as the Nav Sys Tank Average display, the 7 percentages above for me added to 27.35%, divided by 7 tanks = 3.9%. So for me, the Nav Sys continues to read ~4% higher MPG than pumped gas.

On this Tank before fill-up I had 10 MTE left with 702 miles on the trip OD. This is the third time my MTE read a maximum of 699 Miles To Empty after fill-up, so the '09 will never exceed that number like prior FEH/MMH models can.

GaryG

 

10/24/08 34.06 Pump / 35.8 Nav = 5.10%
11/5/08 34.04 Pump / 35.5 Nav = 4.29%
11/20/08 32.37 Pump / 33.4 Nav = 3.17%
12/4/2008 30.99 Pump / 32.6 Nav = 5.20%
12/15/2008 30.78 Pump / 31.9 Nav = 3.71%
5 tanks ~4.294% Error Rate

So far tank 6 isn't looking to good with the NJ weather. 28 MPG on the Nav

 

Gary- Maybe it is coincidence, but....

Your Nav is reading 3.9% high.
E10 is supposed to lower MPG by 3.5% ( based on btu ).
( But is also supposed to lower emissions by 25% )

Just thinking out-loud... maybe the Nav doesn't know you have E10?
So it is telling what you should have on plain gas?

 

My experience with E10 is it lowers MPG by 15%, not 3.5% in my '05 FEH. The numbers I'm reading from articles puts E10 at lowering emissions less than 2% and even increasing emission above straight gas in some articles not associated with the ethanol industry. I agree with those articles that state E10 is a scam and only Big Oil and the Ethanol Industry benefit.

As far as the Nav Sys reading 3.9% high, it does not compare to my SGII readings which are 3 times as high as the default settings compared to the Nav Sys. I had one SGII set at 11.8% lower and still got a Tank reading of 52.5mpg when pumped gas was at 51.8mpg. I've posted new photos today on Cleanmpg.com of my Nav reading and SGII readings and new adjustments for my ninth tank:
http://www.cleanmpg.com/photos/showg.../500/ppuser/36

You can also see the maximum Miles To E the '09 will ever read in one photo.

GaryG

 

10/24/08 34.06 Pump / 35.8 Nav = 5.10%
11/5/08 34.04 Pump / 35.5 Nav = 4.29%
11/20/08 32.37 Pump / 33.4 Nav = 3.17%
12/4/2008 30.99 Pump / 32.6 Nav = 5.20%
12/15/2008 30.78 Pump / 31.9 Nav = 3.71%
12/28/2008 28.07 Pump / 29.0 Nav = 3.33%

Those 20 deg mornings killed us last week.

 

Hi Mike

That now puts your 6 tank averages for the Nav Sys percentage above pumped gas at 4.13%. My 7 tank averages is 3.9% so we are getting close to a 4% average that the '09 FEH/MMH Nav Sys reads higher than gas pumped.

I think I would be using alot of DFSO in that cold weather of yours to increase MPG. I use it above 40mph as much as possible when I can't go EV. Just slowly accelerate and coast in "D" over and over. It is a P&G technique that's is good in any weather. A steady state speed in a vehicle that has an aggressive fuel cut like our '09 FEH is a waste of MPG and even worst in cold weather.

GaryG

 

The Society of Automotive Engineers' has a voluntary maximum speedometer error rate standard of +/- 4%. The NTSB has no manditory maximum error rate as far as I know. We should all check and see if our spedo's are off by the same amount.

I can't find the article but IIRC Toyota got sued over a 3.75% error rate and had to shell out $6 million or something like that to people who leased their cars due to overcharging for millage and artificially shortened warranties. After that Toyota "corrected" the software "error" and the speedo error rate dropped significantly.

 

The speedometer in my '09 is just about right On but my '05 reads ~2mph higher. I've checked it many times with those radar trailers put out by the police and it's pretty much on the money. One thing I should note to everyone is the '09 at 40mph in EV is truly 40mph where my '05 said 40mph in EV but I was really only doing about 38mph. The '09 does truly have a faster and stronger EV speed than prior models.

Maybe that lawsuit caused Ford to get their act together.

GaryG