FFH Warm Up Stages

[hybridbear]

I know, im just saying in general its a crappy programing issue that causes us to have to do this. When the ICE is cold it should come on even if it just idles and doesnt power the car instead of waiting untill the batterys are almost dead and than starting it.

 

Wouldnt you agree?

You mean the way the Toyota hybrids do it? If you have a car that doesn't allow you to skip S1a no matter what (as it seems the Toyota hybrids are programmed) then yes it makes sense to do what they do and start the ICE almost immediately after starting the car when the ICE is cold to warm up in this stage. You'll also find that in those cases it's better to let the car sit and idle while it goes through S1a rather than drive and deplete your battery. However, being able to skip S1a by shifting into L and back to D is the best option for fuel economy.

 

Since we've come to the reasonable conclusion that S1a exists for the purpose of EPA emissions testing to reduce the production of GHGs and smog forming pollutants over the short period during the EPA test for which emissions are measured, then S1a can't be done away with. But skipping it in the FFH leads to better MPGs. And better MPGs mean less gas is burned. And less gas being burned means less pollution. Even if you momentarily pollute more by skipping S1a you'll burn less gas in the long run which ultimately reduces pollution.

Edited October 27, 2015 by hybridbear

[Eddie Sessum]

But even than, when you first start the car it needs to warm up the o2 sensor, etc etc. Why doesnt it start the engine right away to begin doing that instead of making us drain the battery before the engine comes on. Than when it comes on it instantly needs to give full power because our battery is depleted.

[acdii]

The ICE actually runs more efficiently under full load than it does under partial load. Reason being you put that gas being burnt to work instead of just being wasted to idle the ICE. I have found that under load where the RPM is low, while propelling the car at a steady speed is when I get the best ICE FE. There are certain roads I take that get better MPG while using ICE than P&G.

 

The difference between the new FFH system and the others is that the drive train can do two things at once, where the others cant. The HSD can charge the HVB while under power, but no where near the rate at which the Ford system can. Ford can power the vehicle while giving a good amount of energy back into the HVB, where the first Gen and the HSD rely mostly on braking to recharge the HVB. This is what makes the Fusion more efficient than the others. When you consider the size and weight of the Fusion compared to the Prius, and getting at or near the same MPG, that says a lot about the new drivetrain.

 

The downside of it, you have to be very diligent in driving to get the max out of it, where the older generation Hybrids all you have to do is drive to get those numbers.

[hybridbear]

But even than, when you first start the car it needs to warm up the o2 sensor, etc etc. Why doesnt it start the engine right away to begin doing that instead of making us drain the battery before the engine comes on. Than when it comes on it instantly needs to give full power because our battery is depleted.

Modern O₂ sensors are heated so they don't rely on exhaust gases to heat them anymore. It is more efficient to start out in electric mode until your power demand exceeds what is efficient in EV mode and then switch to ICE operation to warm up. This way we can get from our apartment out of the garage and off the side streets onto a higher speed road before the ICE comes on which makes it more efficient.

[hybridbear]

I updated post #2 (here) with additional data.

[Eddie Sessum]

Something I haven't seen covered.. What is "full" warmup temp to the point where if needed the cooling fans will come on and thermostat opens?

[hybridbear]

Something I haven't seen covered.. What is "full" warmup temp to the point where if needed the cooling fans will come on and thermostat opens?

Good question. I'm not sure I've ever gotten there. On the freeway the coolant stays cooler than in the city even in 90+ temps. On the city the coolant never has gotten above about 90 C according to ET Mode. I don't think 90 C is quite high enough to turn on the fans because I've never heard them when stopped with the windows open.

[Eddie Sessum]

Also has anybody seen if during cooler weather with the ac off if the car closes the grill unless its needed to cool the engine? I know ive heard of some 50's up north.

[acdii]

With the grill covers on I have seen it get above 200*, but during normal driving without them it hits 180* and never goes higher.

[hybridbear]

Some additional notes: Earlier I confused the transition from S1a to S1b with the change from Open Loop to Closed Loop. The transition to Closed Loop happens very quickly after the ICE starts as the oxygen sensors are heated and warm up within seconds. Shifting into L and back to D to force S1b doesn't effect Open Loop vs Closed Loop. The car will go Closed Loop while in S1a. The car can also be forced to jump to S1b but still show Open Loop.

 

Fuel economy is greatly improved by skipping S1a as quickly as possible and allowing the car to warm up in S1b.

[hybridbear]

Many have observed that remote starting their car for heat in the winter doesn't seem to reduce their fuel economy. This is true! And, here's why...

 

The reason why you see better fuel economy has to do with the warm-up stages as explained above. When you remote start your car goes through Stage 1a while parked. It has long been documented by Prius owners that allowing the ICE to warm up in Stage 1a while sitting is best. Since S1a runs the ICE at a very low power demand with retarded ignition timing, the power output is very low and the ICE is not used to drive the car. When you drive and the ICE kicks on in S1a while you're moving you are still depleting the battery even though the ICE is on. This means that when S1a finishes the ICE must work extra hard in S1b to charge the battery to make up for all the electricity you used during S1a to move the car.

 

In the Toyota hybrids you cannot force the car to skip S1a and thus should always start your Toyota hybrid and let it sit idle for a minute or two until it completes S1a. Or at the very least, you want to drive very gently and slowly to minimize the current drawn from the battery. In our Prius I've seen the amps out of the HVB reach as high as 130 amps when flooring it during S1a trying to force the computer to transition to S1b early. The Prius will not allow you to force it into S1b early and will even fully deplete the HVB much lower that it will ever get during normal driving during S1a.

 

In the FFH you can easily manipulate the computer to go to S1b early by shifting to L momentarily and then back to D once the ICE sound changes. This will greatly improve your fuel economy. Otherwise, remote start to make heat should not reduce your fuel economy at all compared to just getting in and driving if you don't force the car to skip S1a. For me, remote start would greatly reduce my fuel economy since I always force the car to skip S1a for maximum efficiency.

 

As far as timing of remote start, 5 minutes should be more than enough time to get the cabin warm using remote start. The Prius ICE typically runs about 50 seconds in warm weather in S1a, but can run up to 3 minutes in cold weather in S1a. The FFH timing in S1a should be very similar. Having the heat on will lengthen the time it takes S1a to complete. The ideal amount of time for remote start is the exact amount of time it takes where you get in and drive away right as the ICE first shuts off or even slightly before it shuts off but after it has completed S1a. The heat will force the ICE to continue running after it completes S1a once the computer shifts operation to S1b. During S1b it is no longer efficient to let the car idle, but it should be driven to complete the warm-up.

 

Even if you don't have a ScanGauge, you can tell the difference because the ICE sound will change slightly when it goes from S1a with retarded ignition timing to S1b with standard ignition advance as needed. Even though the RPMs will stay basically the same when the car is parked doing remote start, you will hear a change in the exhaust note due to the change in ignition timing.

Edited October 27, 2015 by hybridbear

[hybridbear]

I posted some post-PCM update (13B07) temps in post 1 in green

[hybridbear]

One of my questions to Ashley for the Ford technical team related to the warm up stages and skipping S1a by shifting to L and back to D. Below is the reply from Ford engineering.

The ICE warm up is mainly to get the vehicle to be able to meet emissions. Timing will vary on what the reason the ICE is running for. Under conditions when its just warming the ICE only and not providing power then timing can be retarded because no torque is needed from the engine. There will be no damage caused by shifting into low then back to drive though it will change the engine strategy some. The details of why this works the way it does are proprietary.

My takeaway from this is that shifting from to L momentarily and then back to D is a great idea for all FFH owners to improve MPGs and to speed ICE warm up. For me this has become a habit where I don't even have to think about it, I just do it. This definitely improves MPGs by getting the ICE warm more quickly and thus able to turn off more quickly.

[corncobs]

That's interesting to know but for me it sounds a bit harsh and definitely like the quietness of my FFH.

[hybridbear]

That's interesting to know but for me it sounds a bit harsh and definitely like the quietness of my FFH.

There's no change in quietness. You are just tricking the car into being more efficient.

[acdii]

I used to do this, driving away from my driveway would deplete the pack in 5 seconds, and the car was sluggish since as pointed out, no torque being applied by the ICE. Now that I have been remote starting every morning, I no longer need to as the ICE is warmed up and the battery fully charged by the time I pull out of my drive.

[corncobs]

There's no change in quietness. You are just tricking the car into being more efficient.

Really? I did it a few times just to check it out months ago and I could swear that the engines revs are definitely higher.

Edited December 21, 2013 by corncobs

[hybridbear]

Really? I did it a few times just to check it out months ago and I could swear that the engines revs are definitely higher.

When in L the revs are higher, but you only shift to L momentarily and then back to D. As soon as you hear the revs start to increase you shift back to D. Once you're back in the D the revs are normal.

[snowmonster]

HB - I really appreciate everything you're doing here. I really think Ford should include a publication to help their owners extract the most from this car.

 

I got my FFH essentially 8 days ago and it's still been in the 20's and 30's here in Indiana. I've already had one drive of 47 mpg in city driving and I credit that to what I've learned here on the forum. Most of my drives have been around 39 mpg or better except some of the early AM/cold engine ones. I think I'm on schedule to get at least 500 miles on my first tank of gas and that includes the first few days of having no idea how to maximize mpg's other than by driving slowly (until I found these forums)

 

I just ran across the D-L-D trick and will have to try it out starting tomorrow. Just for clarification, do I shift into L once I start moving forward and then back to D as soon as I hear a surge in revs? Does this take about 5 seconds, 10 seconds, etc?

 

Thanks again!

[hybridbear]

HB - I really appreciate everything you're doing here. I really think Ford should include a publication to help their owners extract the most from this car.

I just ran across the D-L-D trick and will have to try it out starting tomorrow. Just for clarification, do I shift into L once I start moving forward and then back to D as soon as I hear a surge in revs? Does this take about 5 seconds, 10 seconds, etc?

 

Thanks again!

Welcome & congrats on your car. I'm glad to share knowledge and am glad to hear that you have found the info useful.

 

I usually shift to L right after the ICE kicks on the first time. It takes about 1-2 seconds for the sound of the ICE to change in most cases.

[snowmonster]

Couldn't wait until AM, just went out and drove around the block and there was a noticeable change/surge in revs in L that you just can't miss once you start accelerating with the ICE. It was great to not have the engine constantly on once I kicked it back into D.

Thanks again. Keep it up!

Edited March 27, 2014 by snowmonster

[rjent]

HB, great thread. I have been reading this over the months, and I want to make some observations. While I agree the DLD trick does work, I accidentally figured this out LOL, I also KNOW that remote starting the car improves the mileage drastically. I know what you are saying here, and what Loder says, but I have been doing this, when it is cold, for a year now. There is no doubt in my mind that it makes a huge difference for me and my conditions. I will ask anyone to just go out and put their hand over the exhaust pipe while the ICE is running in remote start and tell me it is burning a lot of fuel. A Briggs and Stratton lawnmower engine is pushing more exhaust gas that the Fusion is, and the bonus is you can set the length of time to run (I believe the min is 3 or 5 minutes) and drive away without all of the EPA programming and a full battery.

 

Say what you will, I think everyone should at least try to prestart their car for short hops or commutes, give it a fair trial. I think they will see the improvements I have.

 

My Post Office is 2 miles away. Without remote start (winter) 29 MPG, with remote start either ice won't start (infinity) or 80 to 100 MPG. Just sayin' :) Heading South on I25 I will see 4 to 5 MPG improvement in a 70 mile commute .....

 

Just my .02

Edited March 27, 2014 by rjent

[snowmonster]

What a great trick!

 

My 2.6 mile AM drive to drop my daughter off at her school and then go to work normally yields about 25 to 30 mpg. With the same weather conditions this AM, I got 50.6 with the engine running a whole lot less!

 

Edited March 27, 2014 by snowmonster

[hybridbear]

HB, great thread. I have been reading this over the months, and I want to make some observations. While I agree the DLD trick does work, I accidentally figured this out LOL, I also KNOW that remote starting the car improves the mileage drastically. I know what you are saying here, and what Loder says, but I have been doing this, when it is cold, for a year now. There is no doubt in my mind that it makes a huge difference for me and my conditions. I will ask anyone to just go out and put their hand over the exhaust pipe while the ICE is running in remote start and tell me it is burning a lot of fuel. A Briggs and Stratton lawnmower engine is pushing more exhaust gas that the Fusion is, and the bonus is you can set the length of time to run (I believe the min is 3 or 5 minutes) and drive away without all of the EPA programming and a full battery.

 

Say what you will, I think everyone should at least try to prestart their car for short hops or commutes, give it a fair trial. I think they will see the improvements I have.

 

My Post Office is 2 miles away. Without remote start (winter) 29 MPG, with remote start either ice won't start (infinity) or 80 to 100 MPG. Just sayin' :) Heading South on I25 I will see 4 to 5 MPG improvement in a 70 mile commute .....

 

Just my .02

That's because gas burned during remote start is counted nowhere...it isn't counted in your trip summary and it isn't counted in Trip 1 or Trip 2...that's why it gives the illusion of improving fuel economy.

[rjent]

I understand the logic, but I agree to disagree. I keep logs on every fill up and mileage. I don't see a drop or gain in MPG on a tank full using remote over cold start and I have done it both ways with purpose. The minuscule amount of gas used is less, IMHO than the gas used to drive while road warming the engine. Also, (I can't prove this yet as I am working with my Ford tech) but the fuel used during remote start IS recorded and calculated in the over all mileage, it is just so small, it doesn't show. You guys can say what you will, but I am convinced it works. I have literally walked out in sub 30* weather and "remote" started standing next to it and let it run until it shuts off. I am telling you, there is no significant fuel burn, there can't be. I think it works because it runs through the three stages without a load on the engine. That engine is so efficient, particularly not under load (except charging the battery for a short time), the fuel burn is negligible. It doesn't run very long at all, most of the time less than the allotted time for warm up. Is the water up to 180*? No, it doesn't have to be. You have to make sure you aren't heating the seats and you are not running the compressor (covered in other threads), but with that said....

 

Think about it, do you really think, as anal as Ford is being with the software and the EPA, if remote start was an issue of lost efficiency, they would even allow it .... I rest my case LOL

Edited March 31, 2014 by rjent