Mileage per tank

It's not the size of your tank, it's how you use it!

 

I've had my Elroy (silver pkg #6) since thursday night, at 170 miles and 36.7 mpg. Been mostly short trips... been working on ways to increase mpg like gliding... I know that my mpg will improve over time and our weather hasn't been over 40 degrees..... which is part of the problem..

I'm satisified with anything over my 14.8 mpg in my jeep wrangler!

 

Follow efusco's advice it is good.
By accelerating briskly you can go to a maintaining speed mode of driving sooner, you do less distance at higher consumption and more distance at lower consumption.

These aren't actual numbers but by way of explaination,
Accelerate to 40mph at 10mpg over 100 yards then 150 yards at 100mpg
Accelerate to 40mph at 20mpg over 250 yards
In both examples you reach the same speed but in the first you use less fuel because you go into cruise mode sooner.

At the bottom of a hill be going a bit fast, at the top of a hill be going a bit slow. Judge traffic and avoid braking, if you have to brake, brake early and light.
Learn to "glide" or coast by going a little fast, lift right off the accelerator then press it down a little until there are no arrows on the energy screen. This works best under 42mph and is easier the slower you are going. Great on slight down hill slopes.
Never use B mode.
Combine short trips or walk. Short trips kill economy
Metro driving below 42mph will get the best economy.
Have fun!

 

I tried to write it all down once. I don't know how much of it will make any sense now days though. Might want to get a ScanGauge though:

HSD (Toyota-Hybrids) P&G tech by Dan... - CleanMPG Forums

Nope. Stay off the electric motor unless your speed is less than 10 MPH. If 10 oz. of gas gets converted to 300Wh of electricity, you only get about 200Wh of that electricity back. So you waste 30% of all the gas you use to charge the pack. I think the number is higher to 50% but I don't want to get into a efficiency debate.

11011011

 

accelerating briskly will always use for gas than accelerating slowly...but in most cases, we have to look at the traffic flow around us. no one can say much if you are at or near the posted speed limit. so it is better to accelerate at a reasonable pace to just above your target speed, then deadband down to a point below, speed back up, etc.

 

It could be argued that the ICE is producing the excess energy to charge the battery at much lower fuel cost than the ICE makes power for the wheels directly because when it is making electric for the battery the engine is also propelling the car therefore frictional losses can be attributed to propulsion rather than power generation therefore power generation could be 70% efficient while propulsion is only 30% efficient then if storage and conversion to kinetic energy is 70% efficient the overall efficiency is about 49%, much better than 30%. Does that make sense?
Maybe it is OK to use the batteries and recharge while the ICE is propelling the vehicle up hills and accelerating.

 

Well here's what I noticed, and read and believe from Hobbit. Cruising around anything between 1300 and 2000 RPM is OK, brisk, or poky, you choose. The only thing you want to avoid is a an arrow going from the battery too the generator (assist). Most of the time at these RPMs you will see no line connecting battery and generator, or a line going from the generator to the battery (regen).

Now a deadband glide (no arrows anywhere) does use battery. I think it draws at a rate of about 5 amps. The MFD won't display an assist or regen of less than 7 amps so you get a blank display. So my point is, that regen during a pulse is not a bad thing, you use that power even in a deadband glide. Do be aware though that the RPM at which assists happen varies greatly based on speed and State of Charge. At 8 bars, all pulses will result in an assist. At 1 bar, no pulse will result in an assist. Once you settle on a route and pulse rate you'll see your pack state of charge stabalize over a few days. When I get to work mine is always 5 bars. When I get home it's always 4 bars. Totally a product of my route and number of pulses going each way.

As far as 70% energy cycle being better than a 30% thermal efficiency, it's an apple to orange comparison. Once the engine has produced the power your already done with the lossy 30% thermal efficiency (power is already arrived at the PSD gear). The only question left is do you use the power that is at the PSD for propultion immediately at 100% efficiency, or store it to and recall it latter, a trip which only has a 70% efficiency? Once the power is produced, better to use it in your pulse and get a nice long glide, than store it in the battery and only get 70% back on your next pulse.

Short answer... The small amount of regen that a moderate pulse generates is ok, but don't then turn around and try to suck the juice out with long EV glides. The Prius will use excess energy in the pack all by itself. Best not to help it along in this regard.

11011011

 

I have a question about the pulse part. I've been practicing over this last week with pulsing and gliding. How long should the pulse be? I ask because I may want to go 40 MPH, so I go to 42, then pulse quickly and try to glide. My speed seems to drop so quickly that I don't feel like I glide far enough to make it worth the accelleration. Also, often in the middle of my "glide," the yellow arrows from the electric battery come on. At that point, based on what you've said here, I should go ahead and accellerate again, starting the process over, not continue with the battery. I've done that a couple of times because my gas mileage was at 99.9. However, I probably decreased my MPG because, as noted above, the engine had to charge the battery more.

Lately, my "Pulse" has been a little more of a sustained push, as I've been experimenting with the gap (i.e., going up to 44 MPH to drop to 40). What I'm doing has gotten me over 47 MPG, but I want to get the best MPG possible, so I want to be doing this right.

Of note, my route to work is laden with 35-45 MPH traffic and several stoplights. It is about 10 miles each way.

 

Takes a few weeks to get the accelerator tuned in just right. Tire pressure has a HUGE effect on how fast or how far your glides are. I usually can tell when I'm loosing pressure because my glides bleed off speed too much. As you decelerate the spot you have to keep the pedal at changes. So as you decel, you have to slightly come of the pedal. I often fell back into assist or regen, so I just throw it into neutral when I glide. I know there are some that caution against this, but most agree it's harmless below 30 MPH. Short periods of small assist (8-10 amps) isn't gonna hurt, just don't go hunting for it. The "yellow arrows" could mean a little or a lot. So if your not digging into the EV mode and just falling off the balance a bit, no big deal.

I spent the first 6 months driving bare foot (also crazy for anyone to do) to try to tune into pedal position. Now I've got enough muscle memory that I can P&G in boots with no difficulty. Really just takes practice and tire pressure to get everything lined up.

Ohh yeah.. smooth roads help, construction sites eat up glides quick.

Edit: That short route is gonna be tough to score big on. Might want to invest in a Block Heater and EV button. Depending on your route, if you can hit 60's you'd be doing fantastic. Route planning is the biggest tip I can offer. Here's the planning I put into mine... but I'm nut!

Dan's Commute
11011011

 

Thanks, Dan. I set my tire pressure a few days ago (to 42/40), but I will keep an eye on it. I am surrounded by construction. Jacksonville is the orange barrel kingdom right now. I'm sure that does hinder the glide...:bolt:

 

the pulse cycle is pretty short for me... if i am doing it (i admit i dont a lot because too lazy or whatever) i accelerate to about 40 mph, then glide with my speed dropping at the rate of probably one mph every 3-7 seconds maybe... never really thought about it much...

but go down to around 32-33 mph, then accelerate slowly back up to 40 and start over...so time between accelerations is usually only a minute apart or so

 

LOVE your license plate. Quite cool.

I'm getting better at P&G and stealth. I've gotten to where I drive all the way into my subdivision and up to my driveway in stealth most of the way. Of course, it is 25 MPH all through there, so it's easy. I'm improving in the 45+ category, too. I feather the pedal a lot and coast. When my MPG drops to 50, I pulse up some, than feather back down again. Seems to be working. My average is now up to 48. I have one little bar left before I have to go back to the gas station. It will be my first fill-up. I think my next tank will be even better because I'm a little more skilled, so to speak.

 

Mileage Per Tank....

On Fill up 1 through 3 - 48.5 to 48.9

Number 4 - I averaged 51.0

Numbers 5 & 6, 48.3 right now...

I've done the stealth mode in my subdivision, and parts of four lane road leading to the major highway out, but not anywhere else... I will have to attempt the gliding when I drive north back home as I can do it for 30 miles going home and possibly up my mileage up to over 49 and perhaps 50+

61.6 as evidenced on the previous member will be hard for me... My drive home from work is 35 miles and I don't glide on I-95 for any reason (too many buttheads driving funny....)

 

i want to say a hearty THANK YOU for all your help.

i will try again and again. i do notice that when i lift off the throttle and depress it slightly, about 1/4" or so, the arrows completely come off, meaning i'm in the GLIDE mode............the most efficient mode..........but it's so %#*@$#% hard to keep it in this mode.

i will tell you this............yesterday, i brought my prii in to the dealer ( my steering wheel was angled at a slight left while going straight ) and forced them to do a computerized 4 wheel alignment. guess what? it was off!

NO, i never scraped any curbs, NO i didn't hit any potholes, NO i didn't fly off any speed bumps.

I think that if people are really driving a prius for the max fuel economy (like me) we should all keep a check on that.

my 2 cents. thanks again for all your comments. i will practice all this technique!

:flame:

 

My car just turned over 2,000 miles, and right now I'm getting 48.9mpg. It keeps improving!!!

 

I've had mine for a week and half and am only averaging 27.4 currently, but I drive 1.6 miles to work, then around town another 10-15 then home another 1.6, so I've done about 150 miles. I am hoping by moding with the EV I should really start seeing some improvement.

 

It seems hard now, but once you practice it for a few months it will be very simple. I remember how hard it was to water ski till I did it for a few days. Then it was easy.

Absolutely. On my other car we scored a 10% boost in fuel efficiency by fixing a very small pull in the alignment. I was amazed!

EV button + Block Heater will set you up nicely. Before both of them my first segment bar was always below 25. Now it's always above 50! Being as nuts as I am, I recommend using the block heater for at least an hour every morning. Even if it's 110 F in the shade where you live. Another tip you might try is to check your oil level. Last time I was in a Toyota Dealer I did a random check of the 3 Prius 2008 models they had in the lot, and 3 out of 3 were low on oil. I don't think they fill them all the way at the factory, can't imagine why. I'd put even money on the odds that your running on too little oil in your pan. I don't know if it will help your MPG, but it certainly won't hurt.


11011011

 

I just got my best tank so far - 49.5 MPG on MFD, 518 miles on the tank. My goal was to get to 500 miles on a tank, which I have never been able to do. While driving into work today the last bip started to blink. I filled as soon as possible after that with 528 miles on the tank.

 

I have never be able to put more that 9.25 gallons in my tank and I almost always fill up on 2 pips. My average fill up is 7.226 gallons. Some times I go 80 miles on before the first pip turns off, most of the time about 140 miles and once about 200 miles. I notice that if I get a real high miles (160 or better) before the first pip goes off, my tank fills up with less gas and my next tank full has a low mileage before the first pip goes off.

By the way, the tank that I filled up with 9.25 gallons my check engine light came on and my charcoal cannister and the "pump" for the charcoal cannister had to be replaced under warrenty. The service manager ask me after all the paper work was finished if I top off the tank. He suggested that was a bad idea becuase liquid gas ruins the charcoal in the cannister.

I wish that I could get 9 plus gallons in my tank. I think I hate that bladder.

By the way, I average 360 miles per tank.

 

First fill up (at $3.99 per gallon!), no problem filling up, pump not one of the super fast ones and I got 53MPG! I was at high 52 mpg and checked it just before I reset. :bounce: