Sorry I wasn't very clear.... my speed adjustment is 1% with the handheld GPS used for the adjustment. And iyou are right... its not perfect, 2% was a bit high, 1% a bit low according to the GPS but I settled on 1% because to me it seemed a bit closer. So we agree on that one very nicely.

The 6% was the adjustment I use when I do a fillup for the fuel used. Thats the number that seems rater inconsistent anywhere from 3-10% even using the same pump everytime, but 6% seems to come up more than anything else. Mines at the shop after a bump on its noggin but when I get it back I planned on tracking my fillups for a month or two and collecting an average I could be more sure of.

 

This is good that at least 3 of us can suggest to others to make that easy adjustment to the SG of plus 1% on the speed setting. For those just getting their SG11:

1, Go to set-up

2, You have a choice of engine or speed, push speed.

3, Increase up 1% and save

This will bring your SG11 closer to the correct speed and give you the average MPG more in line with what the vehicle is getting.

GaryG

 

I have my SG speed adjusted 1% also.

This gets me to within 1 mile of the trip ODO per 500 miles.

I don't think I can ask for better than that!
-J

 

I would advise to NOT do this. Your fuel tank is designed to have a vapor EXPANSION area so the vapor recovery system will not be overwhelmed with liquid fuel. Liquid fuel will ruin the charcoal canister and other parts of the evaporative system.

 

I've been wondering about that.... fill your tank from fuel stored underground where its cool..... and then park in a hot parking lot. How much expansion would there be? Enough that it needs a place to go?

 

Well, I'm the one quoted and advised not to overfill the gasoline tank. I can stop and/or modify this habit. One of the questions raised about this vehicle is the true size of the gas tank? How much expansion area is there in the vapor recovery system? Could someone post a diagram of this system?

 

Relax Billy, I was the one who informed you how to get more gas in the tank and I did some research on the tank and EVAP system long ago. Mark may not know that the FEH/MMH uses the "Enhanced Evaporative Emission (EVAP) System. I also had the same concerns Mark has raised when I added so much fuel while on a slope. First of all, there is a huge vapor space that appears larger than the tank from the diagrams I've seen. Second, you will get a warning light if the tank is overfilled after a period of time. I've never got a warning light, and I've added 17 gallons to my tank many times. GPSman1 has claimed he has added 17.5 gallons and no mention of problems.

Are there damages we don't know about yet? I don't think so for a number of reasons. There is a tank mounted fuel vapor vent valve assembly and a fuel tank control valve to prevent overfilling. They also prevent liquid fuel from entering the EVAP canister and EVAP canister purge valve. Safety is now build into preventing this because of vehicle altitude, handling, or rollover conditions.

GaryG

 

This is something Gary and I agree on.

Just last week, I was in a hurry, and drove away after 2 clicks past auto-stop at the pump. My gas needle never did go all the way to full, and my MTE dropped about 45 Miles even though I was drving very well lately.

Topping off as long as you do not spill is harmless.
I can often top off 2.5 gallons or more from first click.
This does nothing for MPG but is the only way I can get 600+ miles per tank.

 

You are correct I will research this and see if I can find the vapor tank size or the differeces in the "enhanced" system.

 

FYI Expansion of gasoline = 0.058%/ºF