"In town" driving

Short trips are mpg killers in the Prius, however, it is all relative to the EPA city rating for the Prius. Compared to other vehicles, the Prius will still outperform most "non-hybrid" vehicles on short trips.

For the price of the Prius, I would say a minimum of 12,000 miles driven per year is cost-effective to own one. It's a great car but if cost is a factor in your decision you should compare your cost per mile vs. buying a cheaper, used vehicle (taking into account miles driven per year, Prius mpg vs. used car mpg, etc.). If cost is not your biggest factor in the decision, the Prius is a great vehicle.

In regards to the gasoline engine kicking in at "35 mpg" I think you have the current Prius model confused with the Prius plug-in...due for release in the next couple years. The current Prius engine will run at initial start up until it's temperature reaches 160+ degrees. At that point the electric mode is available under 41 mph (using a feather foot to keep it in EV mode).

 

Hi Mel,

Nope, that is not right. The gasoline engine kicks in when ever there is a demand for power beyond what the car would let the battery provide. Which is pretty low level of power, and varies depending on the situation. About 10 seconds after starting the Prius, the engine comes on. This is to lubricate everything. And for the first minute of travel the engine will be running, but wont be allowed to provide much torque to the drive train. The battery is used for this. The purpose of this is to thoroughly lubricate everything and to get some warmup of the catylytic converters. After this time, if you come to a stop, the engine will go off. But not before. As the battery is being used for torque, its best to avoid steep up hills in that first minute of operation.

The best way to get good mileage around town is to go to the farthest destination first, and do it on 35 to 40 mph roads with minimal stop signs and lights. This way the car rapidly gets through the 5 stages of warmup. After that, one can pulse and glide between the destinations back towards home. Even for medium length trips (20 miles or so) its best to start down a path that has the car rolling for the first 5 minutes.

Allot of short trip commuters use a block heater, even in the summer, to about half the warm-up time.

Electric cars have the best efficiency for short trips. The range of the electric car needed is about twice your typical trip, to avoid fully exercising the batteries to their design limit. Electric cars are not well developed for cold climates. What would be needed is a fuel-based battery and cabin furnace. Once the batteries are warmed up at like a 70 % furnace efficiency things would be great. The 2010 Prius has a feature which should help short trips - it has a coolant heater that uses the engine exhaust during the warmup phase.

 

I do that all the time post office is 1 mile away and stores are.5 miles away still get 42 average around town, I also live in a small town

I have only used 2 tanks and my son drove it over a hundred miles and messed my average up

 

Unless you need a "new" car I'd go used (Prius or otherwise) and pick up a nice bike to make the really short trips with. Save money, gas, the environment and get some good exercise too! If it's only a half a mile or a mile into town to run errands and you don't need to drive it...bike it in the summer months.

 

The answer to this is simple: the tank can't actually hold 11.9 gallons and the pips do not disappear in a linear way. In other words, even though there are 10 pips, it's not like each of them represents 1/10 of the tank. As many have noted, the first pip takes a long time to disappear.

(BTW: I'm assuming that you have a <= 2009 Prius in the next paragraph. If not, please ignore)

On the other point, your Prius is equipped with a rubber bladder in its gas tank to help minimize emissions. What this means is that, although your gross tank size is 11.9 gallons, you'll almost never get that much gas into the car. People routinely max out at 10, 9, or even 8 gallons. As you will find out in a few months, the rubber bladder is much less pliable in the cold, so your "winter tank" will be even smaller. It's something that most of us have learned to live with. Don't try to guess how much gas is left in the tank; just fill up when the gas gauge gets down to 2 pips or so.

 

Hybridmel,

Good to hear you love your Prius! And, you are getting significantly better mpg than you did in your old car so that's a big bonus.

In regards to your short trip to work each day you are going to have a tough time getting up to temp and able to use all of the options the Prius offers in terms of maximizing mpg from an engine/EV standpoint.

In the warmer months you might be up to temp near the end of your commute but in the winter I doubt you will come close to that. If you can get into EV mode at some point of your trip that will help you raise your mpg and you won't be using that much battery power to do it that you won't recapture in the brakes over 1.5 miles. To combat the warming up issue you could invest in an EBH (engine block heater...$40-50) to have your car nice and toasty prior to starting. This might get you up to temp very quickly or at least increase your mpg over the 1.5 mile commute.

I'd advise getting familiar with pulse and glide (and against the advice of some on this site...neutral coast) to raise your mpg. Make sure your tires are at or near max psi. Look into installing a simple grille block with foam pipe insulation (not recommended in 75+ degrees ambient temp).

Short trips are mpg killers in the Prius (and any car for that matter) so if you are running errands I would recommend leaving the car on if you just have to run in a store quickly so you don't have to go through the Prius start up cycle when returning to your car (this advice is only advised if your car is already up to temp when you stop at a destination and won't be in there longer than a few minutes). Make sure you power down all electronics in the car (lights, radio, AC, Ipod, etc. before you exit the car to run in a store/shop) to save on the battery.

 

Lots of mpg help at cleanmpg, too. See general hows and whys article by xcel, then his Prius II article.

I did a chart of the warmup cycle of the Prius II posted in the knowledgebase here at PriusChat. Contains lots of links to guide you to more complete discussions.

 

Effectively it is more like an 8-10 gallon tank when going from full to flashing pip--and this can be highly variable in the same car from fill up to fill up. (My last fill inexplicably went over 10 gallons...about a gallon and half more than the MFD mileage indicates it had used. After so many 8 and 9 gallon fills I'm thrilled to get some respectable tank capacity!) The combination of bladder and digital gauge makes the fuel level very uncertain compared to normal gas tank/gauge combinations.

Think of the pips like you would the markings on a normal analog gauge. On the analog gauge when the tank is full it is usually noticeably above the full mark. Mine typically have as much as 1/8th tank above the full mark. And when a tank with a working analog gauge is empty it is usually well below the last mark--how much I don't know as I've never run out in a vehicle with a working gauge despite getting within a few tenths of rated capacity in them. In the case of the Prius, the last mark is the flashing pip...somewhere in the 1 pip range. You have NO indication below the flashing pip and the bladder makes the tank unreliable/variable below this indication so fill ASAP when the flashing pip comes up. People have gone empty at 2 pips. If that happens then the gauge needs calibration or something is odd with the tank anyway.

From what I can tell the calibration of mine might have as much of an 1/8th of a tank below that flashing pip. BUT because of the bladder there is no way to know and it might be right at empty, and/or the pump might not be able to suck that last amount of gas out.

 

2010 Prius has a new way of warming up the car. It is designed to improve MPG for short trips and lower the emission.

We do not have enough data from owners to find out how much better the Exhaust Heat Recovery compares to the Coolant Bottle system.

 

Thanks, but you very well could have been speaking Chinese, and I probably would have understood more than what you just said. I may need to invest in Prius for Dummies.....do they make that?

For example, I have no idea what "up to temp," "EV Mode," or "max psi" mean.

I keep trying pulse and glide, and because I am constantly going up and down, I "pulse" and then I try to keep it in the same mph, but when I even lightly tap the accelerator, it, well accelorates, but if I am not tapping the accelerator, the mph drops, and continues dropping. Arrrgh.[/quote]

Sorry for the lingo...here's the trimmed down version (and I'm sure they make a Prius for Dummies book if you google it)!

Up to temp means getting your engine temp up to or past 160-165 degrees to make EV mode accessible. This is done by simply driving the car normally while the engine heats up to temp. Under 160-165 degrees you cannot use EV mode to run on battery alone.

EV mode (when up to temp) is the mode where you can stay below 41 mph and with a feather foot use battery power only to run the car (anything harder than a feather foot on the gas will force the gas engine...also known as ICE or internal combustion engine...to trip and you are back running on gas again).

For you, running EV mode as much as possible on your very short 1.5 mile commute is ok because the car (via the brakes and upon startup) will regenerate the battery for you so you really don't have to worry about draining the battery too low to force the ICE to come on and regen the battery for you. Alot of people try to avoid EV mode over extended lengths because over greater distances it takes energy from the gas engine to regen the battery but in just 1.5 miles you should never drop too low on your battery...always keep an eye on it to become more familiar and comfortable with what works for you on your commute in your driving conditions.

Max psi is inflating your tires to or near the max psi listed on the side of the tire. If you are running integrities, max psi on the tire is 44 lbs. I have Integrities and I run 44 psi on the front and 42 psi on the rear. Max psi in tires will increase coasting and generally is accepted to increase mpg (all conditions being the same) by at least 2-4% depending on what psi you are running right now.

With pulse and glide, up and down hills work in your favor. You pulse (moderately) up the hill and then ride the glide down the other side of the hill. Then repeat on the next hill. On the glide you will have some engine braking (which is why your speed drops as you mentioned) that will ultimately slow you down so a little extra pulse at/near the top of the hill might be necessary to get you down the hill and part of the way up the next one.

This might be beyond your current skills, but, on normal pulse and glide I use neutral coasting to extend my glide. After pulsing to the top of the hill at the moment I am ready for my glide I go into neutral and ride the hill down and part of the way up the next or onto flat ground while continuing my coast. This eliminates the engine braking and extends my glide.

Note: The neutral coast technique takes some practice and is generally frowned upon on this site...use at your own discretion. Some argue it doesn't allow the brakes to regen the battery, some argue it is not safe...I use it...decide for yourself. From a vehicle safety standpoint, DO NOT USE NEUTRAL COAST IN THE PRIUS OVER/NEAR 60 MPH...it will/or can overspin the engine (I believe the actual figure is over 62 mph but I don't use it over 55 mph). Done correctly, it is safe for you and the car...again...up to you!

 

Hilly terrain doesn't automatically mean bad mileage. I did better than 50 mpg driving through the Rockies, with some passes at 12,000 feet. That is considerably hillier than southern Indiana.

Short trips, on the other hand, are mileage killers for all cars with combustion engines. You notice it more with the Prius because of the instrumentation and high mileage.

Tom

 

Nope. I meant older than '09. If you have an '08, your car has the bladder. Everything that I said still applies. So, are you basing your "bad mileage" claims on your guesses about how much gas is still in the tank? If so, you can't really do that, since you don't know how much gas is in the tank. We can talk about ways to improve your mileage, if you like, but repeated tests have shown that the numbers on the MFD (i.e. the screen) are pretty close to dead-on.

 

It WILL increase your MPG for short trips/commutes. The engine block heater will get the hybrid system thinking it's warmed up much faster than just driving the car. In typical 60F weather I've seen the first 5 minutes jump from 25MPG w/o block heater to 35-40 MPG with block heater. And you can get it installed for free .

Wayne

 

You might want to come to Hybridfest in Madison, WI, in July to get some personal assistance with understanding your car. The volunteers love to share their expertise. Perhaps FireEngineer will be there to install the engine block heater for you.

Ask your friendly neighborhood service station attendant to show you how to check your tire pressure.

I reset my consumption screen for every refill because I enjoy tracking the seasonal changes. For the first 40 - 50 miles the mpg will have more variation than the rest of the tank mileage, in my experience. Sorry, I'm too exhausted tonight to show the mathematical reasoning for this. But basically, the shorter the distance traveled, the greater the impact a change in gasoline consumption will have on the fuel efficiency calculated.

 

Let me add a little to the pulse and glide information. Start with the display set to the energy screen (the one with the turning wheels and arrows). When you accelerate you will see the arrows indicating that either the gas engine (redish arrows), the battery (yellow arrows flowing toward the wheels) or both are powering your car.

When you get up to a speed not greater than 40 mph, let up all the way on the accelerator. You will see green arrows flowing toward the battery. At that point, you will be coasting with mild regeneration. Now ease your foot back down on the accelerator very gently and make the green arrows go away. Now you should have no arrows at all. That is gliding. There will be no drag from regeneration and no power flowing to the wheels. The car is in sort of a free-wheeling mode. You have not touched the gear selector - the car is still in drive.

If you see yellow arrows going from the battery toward the wheels, you have pressed a little too hard, back off a little till the arrows dissappear.

If there is enough down hill and you glide up to 41 mph the engine will start up. When I am gliding and get up to 40 mph I let up on the accelerator and coast. There will be green arrows going toward the battery and you will feel the car slow down just a little. When I get back down to 38 or 39 mph, I press down on the accelerator just a little to make all the arrows go away.

Sometimes traffic conditions will not let you do much gliding, no need to make other motorists mad, they can get that way all by themselves now-days.

After you practice for a while you can leave the car on the consumption screen and still feel the minor changes as you pulse and glide. Good luck and have fun.