Regular gas?

[Skydogz]

Wait a minute, don't wimp out on us now. LOL When you get close to 0 miles put a two gal gas can in the back and run her dry. With any luck you will be able to EV to a gas station, if not you got your two gals. BTW it probably will happen going down hill, you have more EV range that way. Things to do when you run out of gas, look and see how much HVB you have. Look for a gas station and if it is close EV there. If not then find a safe place to stop and put the gas can in the car. Amazingly you can actually run the HVB down to the point it can't go EV any farther and still put gas in it and the ICE will still start instantly. :) :shift:

 

Paul

 

It has a separate battery for starting the ICE, good thinking!

[Skydogz]

1/16 of 13.5 is 0.84.

Well I get the "low fuel" warning at 40 miles to empty and have two gallons left when I fill there.

So at "0 miles to empty" I should have 1 gallon left which is between your two calculations!

[Skydogz]

.

 

Ford's are designed to have 1/16th of a tank left when it says 0 miles to empty. Given the 13.5 gallon tank, that means you have about 1.2 gallons left at zero miles to empty. No need for any experiments.

1/16 of 13.5 is 0.84.

[Waldo]

1/16 of 13.5 is 0.84.

 

D'oh, too much math for a Monday morning...

[ptjones]

Been there, done that, and $2500 later had all new wiring in the trunk along with a new fuel pump. Pump seized from running dry too many times and for some reason did not blow the fuse, but melted the wiring instead. Running a tank dry as a test to see how much fuel a tank can hold is VERY bad advice. Does it really matter any way? Just fill it before or when DTE hits 0 and dont worry about it.

I talked to Service Manager and He said that the fuel pump only runs for a few seconds after ICE stops.

 

Another risk to running out of fuel is running the engine lean and creating detonation. On my 94 RX7 turbo, the rotary engine is so sensitive that there have been reports of people who ran out of fuel while running under boost and blowing the apex seals after just one occurrence. That's why everyone who autocrossed them always ran with the tank full, despite the performance disadvantage of the extra weight. Now I don't think our FFH engines are particularly vulnerable to this condition, but if you run out of fuel in any engine while it is under high load, you risk causing damage.

Also when you overfill the tank, that extra gas isn't going in the tank. It's going into the evap canister where it will eventually have to be purged out, resulting in decreased fuel economy and rougher engine running. Plus over time it will muck up the evap system and you'll eventually get a check engine light.

 

Ford's are designed to have 1/16th of a tank left when it says 0 miles to empty. Given the 13.5 gallon tank, that means you have about 1.2 gallons left at zero miles to empty. No need for any experiments.

There really is no comparison between old engines and new high tech hybrid ICE. The ICE will shut off hundreds of times on a FWY trip which would be the highest load situation without damage to the ICE. I posted a quote from OM on filling up the car and doesn't say anything about over filling other than the environmental hazard of dumping gas on the ground. I looked at the Ford Service Manual and I can't find a evaporation canister, and I know what size of tank I have in my CMAX 14gal which is a half gal. more than OM says. I would guess the FFH is about the same since the hybrid systems are identical.

 

I think it is important to promote the facts starting with information from OM and SM and not getting confused by the way things were done in the past. IMHO :)

Paul

[Waldo]

I talked to Service Manager and He said that the fuel pump only runs for a few seconds after ICE stops.

 

There really is no comparison between old engines and new high tech hybrid ICE. The ICE will shut off hundreds of times on a FWY trip which would be the highest load situation without damage to the ICE. I posted a quote from OM on filling up the car and doesn't say anything about over filling other than the environmental hazard of dumping gas on the ground. I looked at the Ford Service Manual and I can't find a evaporation canister, and I know what size of tank I have in my CMAX 14gal which is a half gal. more than OM says. I would guess the FFH is about the same since the hybrid systems are identical.

 

I think it is important to promote the facts starting with information from OM and SM and not getting confused by the way things were done in the past. IMHO :)

Paul

 

Then perhaps you should start by checking section 303-13 in the Service manual, it has several pages describing the evap canister on the FFH. You could also look under a car and you will see it between the two cross rails of the rear subframe.

 

You also seemed to ignore the very first paragraph in the fuel filling section of the OM which says: "Do not overfill the fuel tank. The pressure in an overfilled tank may cause leakage and lead to fuel spray and fire." You also didn't quote the part that says "Avoid running out of fuel because this situation may have an adverse effect on vehicle components." or the section under emissions where it says: "To make sure that the catalytic converter and other emission control components continue to work properly:

• Use only the specified fuel listed.

• Avoid running out of fuel.

• Do not turn off the ignition while your

vehicle is moving, especially at high

speeds."

 

Shutting off an engine under a controlled situation as the FFH normally does is a totally different scenario than running out of fuel while under load. The computer removes all the load before it shuts it down, it knows exactly how much fuel it is going to supply and can control the mixture fairly precisely. When you run out of fuel, the pressure goes down but the computer doesn't know that right away. You get a partial amount of fuel in the combustion chamber which causes a lean condition that can cause detonation if the circumstances are just right.

Edited April 7, 2014 by Waldo

[Waldo]

BTW this forum is to help FFH owners with questions that aren't answered in the OM. :)

 

Paul

 

So are we supposed to answer the questions that aren't in the OM, or are we only allowed to use facts that are published in the OM??

[ptjones]

 

So are we supposed to answer the questions that aren't in the OM, or are we only allowed to use facts that are published in the OM??

I didn't say "ONLY" answer questions that aren't in OM, I consider that a starting point to build our experiences on.

 

I notice you are still ignoring the OM definition of over filling the gas tank." Note: a fuel spillage concern may occur if overfilling the fuel tank. Do not overfill the tank to the point that the fuels able to bypass the fuel filler nozzle. The overfilled fuel may run down the drain located below and in front of the fuel filler door." It sounds to me like you can fill it to the fuel filler nozzle. IMO

 

Waldo said:

"Shutting off an engine under a controlled situation as the FFH normally does is a totally different scenario than running out of fuel while under load. The computer removes all the load before it shuts it down, it knows exactly how much fuel it is going to supply and can control the mixture fairly precisely. When you run out of fuel, the pressure goes down but the computer doesn't know that right away. You get a partial amount of fuel in the combustion chamber which causes a lean condition that can cause detonation if the circumstances are just right."

 

I disagree with you on this point from actual experience I have run out 3 times and it is no different than normal transition into EV mode. It would be interesting if you could find any FORD Hybrid info that states that this is harmful for the engine. IMO

 

BTW my CMAX is still running great with 52K miles and I believe I still have the best MPG for tank of gas of 65.4mpg for any FFH/CMAX. :) :shift:

 

Paul

[Waldo]

I didn't say "ONLY" answer questions that aren't in OM, I consider that a starting point to build our experiences on.

 

I notice you are still ignoring the OM definition of over filling the gas tank." Note: a fuel spillage concern may occur if overfilling the fuel tank. Do not overfill the tank to the point that the fuels able to bypass the fuel filler nozzle. The overfilled fuel may run down the drain located below and in front of the fuel filler door." It sounds to me like you can fill it to the fuel filler nozzle. IMO

 

Waldo said:

"Shutting off an engine under a controlled situation as the FFH normally does is a totally different scenario than running out of fuel while under load. The computer removes all the load before it shuts it down, it knows exactly how much fuel it is going to supply and can control the mixture fairly precisely. When you run out of fuel, the pressure goes down but the computer doesn't know that right away. You get a partial amount of fuel in the combustion chamber which causes a lean condition that can cause detonation if the circumstances are just right."

 

I disagree with you on this point from actual experience I have run out 3 times and it is no different than normal transition into EV mode. It would be interesting if you could find any FORD Hybrid info that states that this is harmful for the engine. IMO

 

BTW my CMAX is still running great with 52K miles and I believe I still have the best MPG for tank of gas of 65.4mpg for any FFH/CMAX. :) :shift:

 

Paul

 

I quoted the OM where it said "Avoid running out of fuel because this situation may have an adverse effect on vehicle components." That includes the engine. Just because you've done it three times doesn't mean that in a different situation (like in the middle of a high-throttle merge onto a freeway) it wouldn't do damage. It also could be cumulative over time, maybe three doesn't cause noticeable damage, but by 10 or 20 times it would add up.

 

I'm not saying you will destroy your car every time you run out of gas. I'm just saying passing on advice to the general public as if it's impossible to do any damage from running out of fuel is not a good idea. People need to understand the risks of what they are doing when they are doing something that the OM specifically says not to do.

[Skydogz]

Deliberate running out of gas in a Cmax is probably not as serious as in a hybrid, I would never do it on purpose in any vehicle.

What bugs me is not being able to get my 600 mile badge even if I ran gas and battery dry!

[ptjones]

 

I quoted the OM where it said "Avoid running out of fuel because this situation may have an adverse effect on vehicle components." That includes the engine. Just because you've done it three times doesn't mean that in a different situation (like in the middle of a high-throttle merge onto a freeway) it wouldn't do damage. It also could be cumulative over time, maybe three doesn't cause noticeable damage, but by 10 or 20 times it would add up.

 

I'm not saying you will destroy your car every time you run out of gas. I'm just saying passing on advice to the general public as if it's impossible to do any damage from running out of fuel is not a good idea. People need to understand the risks of what they are doing when they are doing something that the OM specifically says not to do.

I'm not suggesting running out of gas as an regular occurrence, but to do it once to find out how big your tank is, is not a big deal.

 

"Avoid running out of fuel because this situation may have an adverse effect on vehicle components." It would appear that all FORD OM say this which sounds like Lawyer Boilerplate with the terms "Avoid" and "MAY". Also it would be very hard to run out of gas in a high load situation because gas moves to the back of the tank, so it would appear you can only run out of gas in a low load situation where gas moves away from the fuel pickup, towards the back of the tank. Of my three times, two where down hill and one on level ground. BTW when you run out of gas the ICE stops very quickly, no running lean or buffeting, just like it would normally going into EV. So I'm guessing you aren't the one that is going to find out how big a FFH tank is. LOL :) :shift:

 

Paul

[hybridbear]

Deliberate running out of gas in a Cmax is probably not as serious as in a hybrid, I would never do it on purpose in any vehicle.

What bugs me is not being able to get my 600 mile badge even if I ran gas and battery dry!

Umm...the C-Max is a hybrid lol

[hybridbear]

I'm not suggesting running out of gas as an regular occurrence, but to do it once to find out how big your tank is, is not a big deal.

 

"Avoid running out of fuel because this situation may have an adverse effect on vehicle components." It would appear that all FORD OM say this which sounds like Lawyer Boilerplate with the terms "Avoid" and "MAY". Also it would be very hard to run out of gas in a high load situation because gas moves to the back of the tank, so it would appear you can only run out of gas in a low load situation where gas moves away from the fuel pickup, towards the back of the tank. Of my three times, two where down hill and one on level ground. BTW when you run out of gas the ICE stops very quickly, no running lean or buffeting, just like it would normally going into EV. So I'm guessing you aren't the one that is going to find out how big a FFH tank is. LOL :) :shift:

 

Paul

 

I quoted the OM where it said "Avoid running out of fuel because this situation may have an adverse effect on vehicle components." That includes the engine. Just because you've done it three times doesn't mean that in a different situation (like in the middle of a high-throttle merge onto a freeway) it wouldn't do damage. It also could be cumulative over time, maybe three doesn't cause noticeable damage, but by 10 or 20 times it would add up.

 

I'm not saying you will destroy your car every time you run out of gas. I'm just saying passing on advice to the general public as if it's impossible to do any damage from running out of fuel is not a good idea. People need to understand the risks of what they are doing when they are doing something that the OM specifically says not to do.

I think that we can officially put an end to this discussion now.

 

Paul - no one is telling you that you can't run your car out of gas if you want. But be careful about recommending that other owners do something that is expressly advised against in the Owner's Manual, even if you think the OM is wrong.

 

Waldo - If Paul wants to run his car out of gas and risk damaging components, that's his decision and let's let him take that risk. It is now very clear that the OM recommends against running your car out of fuel and those points don't need to be repeated again.

[ptjones]

Deliberate running out of gas in a Cmax is probably not as serious as in a hybrid, I would never do it on purpose in any vehicle.

What bugs me is not being able to get my 600 mile badge even if I ran gas and battery dry!

REALLY! LOL CMAX has the same hybrid system as a FFH. I could show you how to get 800mi on a tank without running out of gas. LOL :) :shift: :yahoo: BTW your FFH runs out of gas everytime it goes into EV mode.

 

Paul

 

Paul

[Waldo]

I'm not suggesting running out of gas as an regular occurrence, but to do it once to find out how big your tank is, is not a big deal.

 

"Avoid running out of fuel because this situation may have an adverse effect on vehicle components." It would appear that all FORD OM say this which sounds like Lawyer Boilerplate with the terms "Avoid" and "MAY". Also it would be very hard to run out of gas in a high load situation because gas moves to the back of the tank, so it would appear you can only run out of gas in a low load situation where gas moves away from the fuel pickup, towards the back of the tank. Of my three times, two where down hill and one on level ground. BTW when you run out of gas the ICE stops very quickly, no running lean or buffeting, just like it would normally going into EV. So I'm guessing you aren't the one that is going to find out how big a FFH tank is. LOL :) :shift:

 

Paul

 

Seriously, draw yourself a little picture and you'll see that you can still run out of gas if the front of your car is pointed directly at the sky. it will just run out a little bit later.

 

I already know how big the tank in my FFH is, it's 13.5 gallons, just like it says in the OM. What I don't care to find out is how much extra fuel I can cram into the evap cannister and it's lines.

[acdii]

No more pissing contest here, OK? I am on Waldo's side here in that I have experienced first hand what running out of gas can do in the long run. Running your tank dry is purely BAD advice for anyone to give. The tank holds 13.5 gallons, the computer calculates how much fuel it thinks is in the tank and displays it on the dash as the fuel gauge and DTE. There is nothing wrong with the tank holding 13.5, but as some have seen, the display and actual gallons can be two different things.

 

Now if you want to do this in a more scientific approach, calculate out how many MPG the car actually is getting, then multiply that by 12 and fill the tank. Drive that many miles before filling up again. If you dont run out of gas and can put in 12 or more gallons, Your good, if you run out of gas, then either your calculations were off, or your tanks DOES have a problem.

 

To me, this is much better advice than driving the tank dry and causing a real potential issue.