New MAX MPG driving tips video

Bob,

You mention up to 41 MPH in the EV mode. I can only go to 24 MPH in EV, 25 and over the EV turns off. Any suggestions? Alan.

 

Whenever your MPG bar is reading 100mpg you are in EV mode even when selecting the EV button is not an option.

 

Make sure that you are not using recycled air — that will always cause fogging in rainy conditions.

 

Ok, I have an observation/question... when I accelerate with the EV mode depressed... (after the car has fully warmed up) I can pretty well accelerate at any rate up to 25 mph before the gas engine comes on (whereas just in ECO mode... I have to accelerate VERY slowly to keep the gas engine from kicking in).

Is it BAD? to practice putting the car in EV mode every time I come to a streetlight... simply to get that first 25 mph before the engine kicks on??

I accelerate up to 25... the gas engine comes on... and I continue my pulse/glide technique.

Sometimes I approach stop/go traffic... at which time I engine EV mode as well.

I'm just curious if there's any reason why I shoulldn't be continually engaging/re-engaging EV mode as I drive?

It seems to be working... in my second tank of gas... mpg estimate is easily in the 57mpg range.

-Jeff

 

It depends.

Let me ask you a question, Jeff. Where did that energy from the battery come from and how are you replacing it?

 

Is this a trick question?

I don't see that the practice has undermined my re-generative braking. True... I don't ALWAYS have enough power to start off from the light in EV mode... but more often than not, I do.

Or maybe you're going to suggest that it's undermining power I should be using later while gliding?
and that is where I'm going to see my biggest gains.

 

No trick question. Just wondering how you were regenerating power. If it is from braking or going down hills then you are ok but if you have to regenerate using the ICE then you are losing energy due to conversion from gasoline to electrical. If the later is the case maybe you could try just brisk acceleration up to cruising speed then gliding to the next stop. See if that enhanced your MPG or not after some practice.

 

I see what you're saying... yeah, my runs between lights/stops are long enough, the ICE actually has plenty of time to re-generate if the braking/coasting isn't there. That 25 mph comes pretty fast too... usually not long after clearing the intersection (with the guy behind me tail gating me, with a frown on his face, at least).

So here I am... in this habit of pressing the EV button each time I come to a stop at an intersection... at least until I hear someone here say that this is a bad practice for some reason.

I heard someone else speculate, in another thread, that using the battery 'too much' might shorten it's life? But isn't that what this car is all about? Minimizing use of the gas engine? If I were going to spare the battery and use the gas engine... I would have just bought a Corolla.

 

Minimizing the use of fuel yes, minimizing the use of the gas engine, umm sorta but not at the expense of using the battery too much.

See the idea is to use the engine AND the battery less. If you have to use the gas engine to recharge the battery then you are using more fuel then if you had just used the engine and battery together. You are taking one form of energy, gas, and changing it into electric energy. There are losses associated with that transfer as dictated by the law of thermodynamics. So if you use EV mode to accelerate off the line then recharge the energy used with the engine then you have used more total energy than had you just accelerated normally with the engine on. If you use EV mode to accerlate and can recover ALL of the energy used via regenerative braking (like down a hill) then you are ok.

It sounds counterintuative but you want to minimize the use of the hybrid battery. Try to acclerate briskly up to your desired speed, then lift off the pedal and gently reapply pressure to the pedal to maintain speed. Then watch for your next stop so that you can life off the throttle way early and coast/glide to your next stop. Like many have said before, drive like you don't have brakes and you'll do well.

 

I guess what this really comes down to... I'm either going to use the battery or gas engine accelerating to 25mph from a stop. I have to use one or the other. As it happens, I'm activating EV mode each time I come to a stop... so it's accelerating under battery power to 25mph. Furthermore, the practice hasn't necessitated changing my driving habits, to some how use more gas to re-charge the battery as a result. So I'm going to take from this that my practice is not a bad one.

 

The point of the hybrid system is to use both the battery and the gas engine. You are assuming you need to choose between the two.

When you use them both to accelerate you are being the most efficient you can possibly be. You also don't use too much battery power so you should be able to regenerate the lost energy during your next stop. Therefore you are not using the engine to recharge the battery. This method has been thoroughly tested.

 

Well then, with the exception of slow, stop and go traffic... I'm using the battery up to 25... and the ICE up to gliding speed.

 

What you say makes a lot of sense as the general idea is that the electric and gas engines complement each other. I wonder therefore what is the point of having EV mode as it would seem than in the long run, more gas would have to be used to charge up the battery?

Assuming I had to travel 1 mile at a very low speed, not exceeding 25mph (due to being in residential area). Would my best bet be using EV mode exclusively or just in ECO or normal mode?

 

I believe the answer depends on the amount of bars you have coming into the mile and more importantly what follows the mile - for instance you will be going down hill and regenerating the battery yes why not use it up but it other cases it is not worth the effort

 

Luckily..I knew about most of these before my test ride... but it was so much fun to try them out! Very proud of my 60 MPG average during my test drive...

 

I agree with the above. If you have another way of regenerating the battery power that does not involve the ICE then go for it.

If you do have a downhill section you can use to regen, try using B during the downhill section and you will regenerate faster.

In some cases you could try to use EV when you first start out in the morning if you will be traveling on the freeway soon. This could reduce some pollution but I've never really tried to analyze the technique to see if that is valid.

In essence EV mode is mostly for parking lot fun and impressing your friends or in rare situations like mentioned at the beginning of this post.

 

If you are starting with a cold engine and just traveling that 1 mile, definitely EV mode because you will avoid the engine warmup routine that eats a lot of fuel. You're better off warming the engine for a longer trip where the fuel used for warmup will be spread out over many miles.

 

Dear Jeff,

I just read the last couple pages. If you're looking for the most efficient driving, I would reduce the amount of EV you're using on acceleration. You're right, it's not a *bad* technique, but it sounds like you're driving for economy, so it's not the best. F8L's description of both motors is right on. You're probably dropping a good couple percentage points of SOC when going all the way to 25 mph in EV. Something like 10-14 mph is reasonable and will only result in a 0.5-1% drop usually, I'd suggest that. I realize these seem like small percentages, but the engine acts much different at 57% SOC versus 59% SOC, for example. After a couple stops and starts like that, you'll easily be down in the low 50s for SOC, and your pulses will be relatively inefficient compared to something more around 58%. Regen typically won't make up for this except on good hills.

Imagine you have 58% SOC. A given pulse might be 30 mpg. At 55% SOC, that same pulse may be 25 mpg. These are approximate, but I think somewhat realistic numbers. You can see if you're pulsing over distance x and trying to glide over 2x, your mileage will vary significantly (75 mpg versus 90 mpg) in those two instances, so although it's hard to see the losses concretely when using lots of EV, they are there in other forms.

"If you do have a downhill section you can use to regen, try using B during the downhill section and you will regenerate faster."

F8L! I can't believe you said that ;-) Normal regen in drive, not B, gives better regen. When possible in traffic, a slight, gentle pedal application over a longer period of time does the trick (while in drive).