Roch, in the PCM/ED manual, it says the Keep Alive Memory stores the warm-up data during short trips between Key-Off till you reach Lights Off temperature (~550F). At lights off, you go closed loop and begin lowering emission till you reach a CAT temp around ~1200F. I go closed-loop in less than a mile on a cold start in the morning without key-off FAS. It takes the head temperature (which infers coolant temperature, same sensor) much longer to allow EV.

It is the restarts with a cold engine which will add more pollutents to the air during key-off FAS. During a cold engine warm-up, the FEH/MMH is using electric power for torque and the ICE stays close to an idle. During this time I get up to 40mph and key-off FAS for about 10 seconds in "N" unless I have to come to a stoplight. Depending on my speed, I may do a last second restart and grab some regen in "L" till I stop. If things go well in traffic, I can usally go my first EV with my SG current trip average above 35mpg.

Today for example I got a call at 4pm saying I needed to get downtown WPB (~20 miles) before the Courthouse closed (5pm) to pick up some work. The last time I drove the FEH was last night, so it was still cold. I FAS during warm-up and was going EV in heavy traffic in less than two miles to I-95. Got on I-95 with a nice draft target. Lost that draft after ~4 miles and picked up another a mile or so down the road till I got off at my exit. At 4:35 I was parked at the Courthouse with 46.8mpg on my SG current trip. This was about 4 miles of city and 16 miles of highway from a cold start. I,m willing to bet I polluted the air far less than most cars on the road making that trip in that amount of time. Forgot to say I started with a very low SoC as always.

GaryG

 

Right-o. Thanks for the extra learning!

Roch

 

Sorry for the detailed example Roch, but you know you wanted to make a point about pollution with the restarts and extended warm-up. The other day it was safety and how danderous. One day it's about how slow hypermilers drive. Face it Roch, it's all about how smart you can get from point "A" to point "B" . You don't have to worry about short trips, cold weather, or any of the excuses used here. They all can give positive results. I offer what I know in detail if anyone ask.

GaryG

 

Um, I asked for some information, you nicely provided it and I thanked you. What's the problem?

 

GaryG — Can you please explain what you mean by 'FAS'? Thanks. I don't seem to be able to find its definition anywhere I've looked.

Stan

 

FAS stands for Force Auto Stop. It's shutting down the engine and can be done with the key, but some people are now doing it now by a switch that cuts the fuel injectors. I don't use the term for hybrids when the ICE shuts down automaticly. I use Key-Off FAS mainly during warm-up, because I pulse and glide in neutral and the ICE will not shut down till the head temperature is ~140F.

GaryG