Quick question, what happens when you run out of gas? Will electric motor continue running until battery pack is empty or will it hit 40 and then completely shut down? Curious if anybody has experience with this situation.

 

GPSman1 has had experience with this as one of the two posters here who have own the 1st generation (05-07) FEH. If my memory serves me correctly, you will get around 1 mile of EV at only 22 mph and then the vehicle winds down like a "top" ending it's spin. This activity is not recommended. I have not heard of anyone in an 08-09 version trying this activity.

 

I've got 8 mte showing when i parked at work today.... I feel like giving this a try. I'll keep you all in the loop. It's 7 miles to home so I'll take the long way and see what's up. Might take 2 trips to work still so stand by and I'll report back in a few days.

If you can't tell i have an 09.

 

I wouldn't recommend running out of gas just to see what happens.... I don't think its good for a vehicle to run out.

 

Well didn't get to try it out. The wife need the ride when I got home so I had to filler up. I did get 2 miles past the 0 mte mark.

Thanks for the recommendation. I'm still going to try it once I can have the car to my self for sometime.

 

Couple of things to keep in mind. I have an 06 FEH.

If you do really run the tank out of gas, the fuel pump will try to keep running for a bit. This will necessarily be running dry and will damage the pump. I doubt it will fail right away, but it's a notch in the belt that will shorten its life.

My FEH will go about 1-2 miles on a normal charge cycle. When there is no fuel left it can go a bit farther since it can then go below the ~40% of charge engine start point.

But this will run some risk of shortening battery life. In flooded cell batteries that are not made for deep cycling, running it down to parade rest damages the battery and does shorten its life markedly. The reason is the difference in volume of reaction products on each side of the chemical reaction.

The traction battery is essentially a bunch of NiMH dry cells and so I expect the issue is diminished if present at all. But there is a clear reduction in cycle life with depth of discharge. See attached graph.

My take is that one time to parade rest does not seriously reduce cycle longevity. But... don't make a habit of it.

 

How does the traction battery deal with "voltage depression"?

 

I would say dirt is the enemy when running out of gas, but that said, the fuel does not come from the absolute bottom of the tank... there is always a "settling pond" if you will.

That said, I would still say, running out of gas to "test" things is probably best on a new(er) car.

I just ran on on 2,000+ mile round trip over 3 weeks through 7 states using nothing but E85... just to prove I could. I wonder how clean my fuel tank and delivery system is now?

Raw Stats:
2053 miles
147.69 gallons
13.9 MPG*
Lowest Price was $0.850 per gallon ( Yes, 85 cents per gallon! )
Highest Price was $1.999 per gallon
Ave. Cost was $1.7445 per gallon

Cost per 2053 miles while towing: $257.65
To beat that on gas while towing, I'd need to get better 19.55 MPG.
That was probably not possible with the head winds I encountered.
But is so close to equal in cost, one cannot say with certanty one is better than the other.

*Towing a 3200 lb. box trailer ~ 60 MPH.

NOTE: I specifically wanted to use E85 when towing since there seems to be a power advantage, while a MPG disadvantage. What I mean is, to pull that trailer 60 MPH on gas, the engine runs at 4500 RPM. On E85, my engine was pulling 60 MPH at 3500 RPM. I don't know about later models, but in the 2005 there is a huge noise difference between 3500 and 4500 RPM. So putting whether it is more powerful or not aside... you can't even listen to the radio at 4500 RPM, and at 3500 RPM you hardly notice the engine.

Second, the engine water temp ran 10 degrees cooler on E85.
Third, the generator motor ran 40 degrees cooler with E85. ( due to the lower sustained RPM's ).

Ethanol, good stuff, if you can get it at the right price.
Oh... I carried 5 gallons of extra E85 in my trailer. Two times the E85 stations were too far apart to make it on 1 tank. Without the trailer, I could have made it through CO, WY, SD, ND, MN, IA, NE with nothing but E85. It is that prevalent out here.

Bottom line, after 3 tanks, my MTE was pretty accurate on E85.

 

WPTSKI: I don’t know what you mean by “voltage depression.”

 

Don’t forget there is a nylon filter sock on the inlet to the fuel
pump. So any dirt won’t get into the pump unless it was fine
enough to get by the sock in the first place.