Hybrid System Indicator and Stealth

not true. in some circumstances its possible to have the engine running and be getting over 100 mpg

 

driving downhill for one. i frequently see 100 to 150 mpg. still burning gas, just not very fast.

now, i dont mean free fall downhills. we those too. those you can regen on. i mean downhill so slight i can hardly tell its going down. those are common

 

most of the time, that be correct. but again, still depends on the mode. in EVO mode, you can get past the centerline without engaging engine.

in economy mode it works, if going fast enough or SOC is low enough. (as the SOC goes up, the speed to keep engine on also goes up making it difficult to force the engine to run at lower speeds)

its always been a given that running in EV mode was not good for mileage because of conversion losses, etc. but on the 2010, at street speeds, its hard to avoid. after you hit 6 bars, you literally have to be going 45+ mph... trying to hit stealth i found that its not as intuitive as it is in the SPM.

usually on the SPM, i would frequently see mpg in the 120 to 180 mile range so that is what i am basing where i need to be on the 2010 and while doing this the HSI is literally all over the place so i am beginning to think the HSI is showing us what the classics were not designed to show and that is the transitions from "full EV, no ICE" to high mileage stealth with is "a little EV along with a little ICE"

 

EV mode appears to give you the highest mileage possible, but we still have to look at where the juice came from and what it took to get it.

if coasting down a big hill and the battery is full from regen then sure, use EV... but if not, then using it will hurt your mileage.

electricity converted from gasoline or any other source for that matter has conversion losses. (regen does too, but its all essentially "free" energy so its all good) so you want to avoid conversion at all costs which is impossible. so only use it when you have too.

the best way to get the best mileage is to drive conservatively, minimizing more than very slight acceleration, eliminating braking as much as possible.

the pulse and glide technique has proven to be the best way to get high mileage but can be inconvenient if there is limited roadway and a lot of traffic.

the purpose behind the process

pulse; is accelerating slowly so only the engine is running and power is being sent to the battery. this works best at up to 45 mph (on 2010) or 41 mph on classics. what you dont want is power draining FROM the battery.

glide ; or stealth this is the "no arrow" situation...now remember, there are arrows, but the amount of power going anywhere is smaller than normal. in this mode its kinda of a situation of optimizing a small EV input with a small ICE input. in this mode you will slowly decelerate but not as fast as coasting in regen and the battery will deplete much slower this way while maintaining speed.

as far as stealth, this is kinda like "coasting" but with removing the regen part.

now, all in all, the #1 thing to remember is the last two words ...maintaining speed

this is the make or break of high mileage. gravity and inertia is what you are fighting, not your car's efficiency. it only takes like 34 horsepower (something like that, dont remember exactly but its some ridiculously low figure) to maintain your Pri on the freeway at 60 mph... but that is because inertia is helping you along. momentum is king, that is where its at...

now with traffic, red lights, etc... that will all drain away your inertia (or at least change its state) your momentum lost, etc.

so we go to #2 thing; anticipation

preparedness, planning, etc... whatever floats your boat, and all that means if you know you have to stop, then prepare for it. coast sooner. i get people behind me who get upset because i start coasting up to a light 4 blocks in advance since i know i will have to brake. well, the longer i take to brake, the more momentum i maintain and the less power i have to expend to get that momentum going again.

anyway back to the question. EV mode is great, but it has its place and to be honest with ya, in nearly all situations, that place is not very big. as you have probably guessed by now, the answer is not a simple one. its one that you must constantly re-evaluate as you are driving. getting the very high mileage is a lot of work, but to get good mileage is not, only a few simple rules to follow and you will be doing well

 

thank you thank you... its my "non-technical" version of a technically complex subject

 

i use the HSI nearly all the time. i feel that it gives me a better idea of what the car is doing. but more importantly, it shows me the boundaries. i can see how much i have to push to turn on the ICE (past the center point in Eco or Pwr) which is better than what the classics provided us.