Tuning the hybrid for greater efficiency

[HeyBales]

Well ok, another PID to add!
Now I'm curious after watching the Rav4 %Load as one of the few things to watch live while son is driving (for sure speed!), how it compares to Mav.

With pounds of gross weight per unit - the Mav has 0.8 lb more per HP, but 3.1 less per lb-ft torque (and that's using Ford combined estimate of 191 HP/ 246 Tq).
So it'll be interesting how much different the %Load is.

I find it wild the Rav4 coasts easier than the Mav in slippery mode on most hills we travel.

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[Tiger Dude]

That's just a number to give the transmission a target. Apparently Ford thinks it runs most efficiently there.

 

[Ranko Kohime]

Another thing that would be nice to tune, and I'm more certain must be tunable: accelerator responsiveness in Eco mode. Like my Prius, the Maverick has Normal, Eco and Sport modes, and while Normal and Sport modes act identical to their counterparts, Eco mode does not make any discernible change to the throttle response.

 

[Ranko Kohime]

Well ok, another PID to add!
Now I'm curious after watching the Rav4 %Load as one of the few things to watch live while son is driving (for sure speed!), how it compares to Mav.

With pounds of gross weight per unit - the Mav has 0.8 lb more per HP, but 3.1 less per lb-ft torque (and that's using Ford combined estimate of 191 HP/ 246 Tq).
So it'll be interesting how much different the %Load is.

I find it wild the Rav4 coasts easier than the Mav in slippery mode on most hills we travel.

I would be interested to know what your results were

As for my continued experimentation, I have noticed sometimes that if the engine is off for an extended period, perhaps a minute or more, then the system I am guessing, enters a warm-up mode for the catalytic converter. Pure speculation on my part as to why, but the behavior is that it will maintain 50% engine load, increasing revs as needed to maintain that for anywhere from 20 to 30 seconds.

It also does this on startup, but so did the Prius, so I consider this to be normal-ish? behavior.

Infrequently, it will not do this, but rather act very much like my Prius, and start the engine at very low revs, but very high engine load. and it is at times like this did I get to briefly enjoy the engine rumble I have been missing since I bought this truck.

 

[HeyBales]

I would be interested to know what your results were

As for my continued experimentation, I have noticed sometimes that if the engine is off for an extended period, perhaps a minute or more, then the system I am guessing, enters a warm-up mode for the catalytic converter. Pure speculation on my part as to why, but the behavior is that it will maintain 50% engine load, increasing revs as needed to maintain that for anywhere from 20 to 30 seconds.

It also does this on startup, but so did the Prius, so I consider this to be normal-ish? behavior.

Infrequently, it will not do this, but rather act very much like my Prius, and start the engine at very low revs, but very high engine load. and it is at times like this did I get to briefly enjoy the engine rumble I have been missing since I bought this truck.

If there is no need for the ICE to recharge like down at 30% SOC HVB and your power needs pushed over the lower line now - the other reasons for the ICE to just kick on is if you have heat enabled.

While under warmer conditions 120 F is the ICE lower limit, such that if ICE is needed for anything - extra power or recharging needs, then the ICE stays on until the cat is 1000 and coolant temp reaches 120 F. Then if HVB is over 40% and power needs below 15% for you (10% me), it's willing to turn off.

If heat is enabled though - now ambient temp and cabin requested temp come into play.
A lower coolant temp is set for ICE turn on, to an upper limit where it could turn off.
Abouts 30 F and low fan/heat 75 selected - about 127 to 135.
Today 12 F and 5 fan/heat 75 selected - 135 to 143 I think I saw.
I've seen higher ranges when colder - so despite coasting off highway where ICE would normally turn off, under the no load condition it keeps running because it cooled so quickly and since not actually used - barely keeps up the lower temp.

Sadly I never kept the scanner data under my eye while we were doing more driving in Rav4 - because we threw in more cty/hwy busy traffic and my eye was on that and not punching a hole throw the floor with my foot! Well, maybe not that bad.

Can you hear the difference in the colder mornings - when the ICE is 1st called for while driving or while warming up parked, when it sounds louder?
Watching the gauges - that's when the Cat reaches 1000 and the system is willing to use ICE power now, instead of basically using EV mode with ICE on warmup.
I think I removed Load% PID before it got colder to track that in my log files.

 

[Ranko Kohime]

I should have provided a bit more detail of my observation: the most reliable way to repeat the behavior is above minimum charge, as in, it does not become a factor at any point, and I will generally turn off the heat when making a brief stop to avoid kicking on the engine, engine hot from having been run on the highway for several hours, stop at gas station, remain in Ready while fueling, pull out of gas station, and if I manage to smoothly accelerate on to the highway, (don’t drop the ICE before entering on-ramp), it will generally start at high load, tapering load as speed is reached.

In the other scenario, after exiting station, activating ICE and getting high load, traffic or a light causes me to lose the ICE, the next kick on will be at the reduced load, high revs.

 

[Master Blaster]

If you want to use high load at low revs to improve efficiency, you need to also factor in NVH factors that are only acceptable on an 18-wheeler and not on a passenger vehicle. I believe that Ford stripped those columns in the decision array out to make the truck much more driveable at a relatively small expense in efficiency.

 

[Cherokee]

Interesting read, this thread.
I have been, ‘Out Geeked’
I still think you guyz are all nuts.

 

[Mavster Mechanic]

If you want to use high load at low revs to improve efficiency, you need to also factor in NVH factors that are only acceptable on an 18-wheeler and not on a passenger vehicle. I believe that Ford stripped those columns in the decision array out to make the truck much more driveable at a relatively small expense in efficiency.

The hybrid is programmed to run at about 70% load just driving you and your kid to soccer practice on level ground.

Towing a trailer uphill in tow/haul mode mine is running at 85% load.

Not 85% of power or capacity mind you.
It can be at low power and relatively high load and inherently it is.

 

[Quest]

It all depends on throttle position in the end.

The the most cost effective way to improve efficiency is to put a 2x4 under the gas pedal.
All the aftermarket devices that connect to the pedal or OBD2 port limit accelerator pedal position (APP) to about 80% or lower

 

[Mavster Mechanic]

It all depends on throttle position in the end.

The the most cost effective way to improve efficiency is to put a 2x4 under the gas pedal.
All the aftermarket devices that connect to the pedal or OBD2 port limit accelerator pedal position (APP) to about 80% or lower

In the hybrid, it doesn't.

It's at ~70% load +/- MOST OF THE TIME.

 

[Master Blaster]

In the hybrid, it doesn't.

It's at ~70% load +/- MOST OF THE TIME.

Huh? Do you mean 70% load on the power meter? I try to keep mine under 10%, with bursts at 30% when climbing 7% grades. I average about 50mpg in the summer and 45mpg in winter. At 70% load I'd bet that you get really poor mileage.

 

[HeyBales]

Huh? Do you mean 70% load on the power meter? I try to keep mine under 10%, with bursts at 30% when climbing 7% grades. I average about 50mpg in the summer and 45mpg in winter. At 70% load I'd bet that you get really poor mileage.

The generic Engine Load value read from a scanner.
Only ICE.

 

[Master Blaster]

The generic Engine Load value read from a scanner.
Only ICE.

So does this generic load value from a generic scanner know about the assist that you get from the electric motor or the peculiarities of a pseudo-Atkinson cycle engine? I'd bet that its load values are for an Otto cycle only.

 

[HeyBales]

So does this generic load value from a generic scanner know about the assist that you get from the electric motor or the peculiarities of a pseudo-Atkinson cycle engine? I'd bet that its load values are for an Otto cycle only.

It's the system reported Engine Load value, not calculated from the scanner - so whatever Ford included in the value for calculations.

But it reads 0 when in EV mode - so it is ICE only. Engine Load is the name of the PID.

It's value does not change on initial cold driving when catalytic temp still too low and basically in EV mode for a bit. So the load value is for idling engine then.

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