New owner? Want MPG help? Read this first.

[squall]

<div class='quotetop'>QUOTE(galaxee @ Jan 24 2006, 07:01 PM) [snapback]196627[/snapback]</div>

This is buried back in the old PC archives and I just did some searching for it to link to it in another post... and since we have so many new owners coming on to PC right now looking for MPG solutions I thought I'd link this article here too.

So please, before freaking out and posting how there's something wrong with your car or whatever other frustration is on your mind, read through this article and take these tips to heart. If this doesn't work, THEN go ahead and post a "please help me" thread and we'll all jump up and offer suggestions

"Why don't I get the EPA Mileage?" by efusco
[/b]

I am a new owner of a 2007 Prius. It is my understanding that using the Automatic Temperature Control in the Prius does not affect gas milage as it would in traditional cars. The system is run off the electric motor in the Prius and reduces significantly the impact on gas milage. i have read this in the literature and heard it from dealers and service personnel. I do use the Automatic Temp Control system regularly and would like to get some clarification on this. the article says otherwise. Does the newer model operate differently? what gives?

One other thing. The manual gives no useful informtion about the reset switch (touch switch on the energy screen). the manual says that the car automatically resets itself every 2.6 gallons of use (Pg 168 of the 2007 model). That does not make sense. Where can one find good information regards how to use the reset?Does it reset completely or does it just reset milage and the MPG is still cumulative? Anyone have good info on this?

And a last real stupid question. when people talk of their milage figures are they using pump calculations or the figure calculated on the energy screen.?

[tomdeimos]

<div class='quotetop'>QUOTE(squall @ Jan 25 2007, 12:54 PM) [snapback]380656[/snapback]</div>

I am a new owner of a 2007 Prius. It is my understanding that using the Automatic Temperature Control in the Prius does not affect gas milage as it would in traditional cars. The system is run off the electric motor in the Prius and reduces significantly the impact on gas milage. i have read this in the literature and heard it from dealers and service personnel. I do use the Automatic Temp Control system regularly and would like to get some clarification on this. the article says otherwise. Does the newer model operate differently? what gives?

One other thing. The manual gives no useful informtion about the reset switch (touch switch on the energy screen). the manual says that the car automatically resets itself every 2.6 gallons of use (Pg 168 of the 2007 model). That does not make sense. Where can one find good information regards how to use the reset?Does it reset completely or does it just reset milage and the MPG is still cumulative? Anyone have good info on this?

And a last real stupid question. when people talk of their milage figures are they using pump calculations or the figure calculated on the energy screen.?
[/b]

The ac in a Prius affects mpg much more than my last car. The difference is the ac in the Prius is far more powerful. This is costly but I am way more comfortable. The idea that you get free ac because it is electric is false. All the electricity comes from your gas tank. The Prius ac is variable output which can make it run more efficiently under some conditions than cars with fixed output, but this can be done other ways too than using electric drive. This benefit can be seen on long trips but it still costs some mpg. With hot weather and short trips the ac is running full power and this won't help you.

MY car is a 2005 and the reset occurs every fillup, or when I push the reset button. It resets the mpg and the miles.

Mileage effects for things like ac use can only be determined from the energy screen. The tank bladder makes every mpg calculation for just one tank off by as much as 20% or more. To get true calculated mpg I calculate over at least 10 tankfuls.
The energy mpg readout is what you should use to see the effects of gasoline type tires etc.

One final point I think you are confused on: The ac electric power comes from the generator/motor but it doesn't run off it when it is running as a motor. The AC has it's own dedicated electric motor.

[cwerdna]

Besides the AC portion tomdeimos that correctly describes, running your heater (having temp set above LO and fan turned on) in a Prius esp. during the initial startup phase can definitely affect your mileage. I've started up, driven thru a parking lot and a short distance to come to a stop at the light, yet the ICE was still running due to the heat being on. The moment I pressed OFF, the ICE shut down. I've also had the ICE start up in order to maintain heat. Again, the moment I pressed OFF, the ICE turned itself back off.

With a regular car, when you're idling, the ICE is always running.

Moral of the story: Don't run the heat during the initial warmup phase unless you're driving conditions will make the ICE run anyway (e.g. you're driving >42 mph)

[efusco]

<div class='quotetop'>QUOTE(cwerdna @ Feb 10 2007, 04:28 PM) [snapback]388158[/snapback]</div>

Besides the AC portion tomdeimos that correctly describes, running your heater (having temp set above LO and fan turned on) in a Prius esp. during the initial startup phase can definitely affect your mileage. I've started up, driven thru a parking lot and a short distance to come to a stop at the light, yet the ICE was still running due to the heat being on. The moment I pressed OFF, the ICE shut down. I've also had the ICE start up in order to maintain heat. Again, the moment I pressed OFF, the ICE turned itself back off.

With a regular car, when you're idling, the ICE is always running.

Moral of the story: Don't run the heat during the initial warmup phase unless you're driving conditions will make the ICE run anyway (e.g. you're driving >42 mph) [/b]

I'd go so far as to say don't run the heat for the first 10-15 minutes even if you're going more than 42mph. It definately delays ICE warm-up if the heat is on. Once you've reached around 180 degrees ICE temp I don't think adding a little heat adversely affects mpg much.

[tomdeimos]

For heater I set to automatic when I want to be comfortable. If I want mpg I set to 2nd lowest fan speed. Then set recirculate as long as windows don't frost. And keep AC turned off.

The difference during warm up is over 5 mpg.

Once the car is warm enough I can use the automatic climate setting usually. I just monitor the engine temps.
Still switch to recirc when I have to drive slow or stop.

No heat would be best during warm up but I find the low fan speed a good compromise.

[DanMichSr]

Yes the Prius isn't for everyone. I live in Maine and travel 8 miles a day to work. I've had the car for a month now and the temp has been anywhere from -15F to 10F. I don't let the car warm up I just get in and drive like some have suggested. I average around 37 to 40 mpg. I think that is exceptional and on longer trips lets say 70 miles one way I average 44 or better and that is with the same temp readings as before and the heater on full force. We had one day at around 30 degs and I could get close to 50 actually 49.3 on the interstate at 65mph and roads leading up to the interstate at 45mph. This is exactly what I expected and think I can get higher once the warmer weather gets here. Before I purchased the 07 Pkg 6 I read tons of things on Priuschat and it was extremely helpful in making my mind up to purchase one. Although I only have 600 miles on it I find it better than what I hoped for. I had a problem when the temp was around -5F below zero when an attendant filled my tank and I knew it wasn't right that it was full. Knowing what has been said on PriusChat I knew it wasn't the car but the way it was filled. Sure enough the next time I filled it PriusChat way and it shut off just when I expected it to as the bladder needs time to expand so when it's cold I slow the fill down and on rusuming the road trip the gas gauge moved from 1/4 to full in about 15 seconds. I might also add that I had a Crew Cab Silverado 2004 that was getting 14.5 in weather like this and spending $60/70 on a fill up was a little to much. Another thing we have had a few big storms where the parking lots at work not having been plowed and I had no problem getting out. It sort of leaped out on the road. LOL.... I was concerned about the fully snow/ice covered roads but have been there and done that with my Prius and was extra careful not knowing what to expect and still don't but know that it is as good as my 04 Silverado in 2wd. Well I better stop rambling on I just enjoy my Prius.

[LanceinOregon]

[size=2]
UPDATE:

For some reason, it was only my first tank of gas that came with my Prius that gave me 29 MPG. Once I got past that first tank, my mileage went steadily up.

I am now averaging 42 MPG, which I find quite satisfying.

I did check my tire pressure, and was shocked when I discovered that my dealer had set the front tires to 42 psi, and the rear to 40!! I had no idea that there were dealers now setting the tire pressure this way.

This has been the coldest winter here in Western Oregon since I moved here in 1993. I am unwilling to not run my heater initially, due to feeling cold. July, August, and September are the only months here that we ever need AC And even then, not all the time in those months. I am keeping my AC off all the time now, after turning on AUTO.

We are still running Winter gas here in Oregon.

Lance

[jimmyrose]

As stated many, many times, the Prius is NOT for everyone. I do not often fall into the category of the people who get the higher mpg numbers. I drive my kids to school (<1 mile each way, two different schools, two different drop-off times, so 2 trips each morning). I'm a Realtor, which can mean I'm driving 45 minutes to show properties to people, or 2-3 minutes. Sometimes I'm showing properties to the same people that are blocks apart, sometimes in different towns/counties on the same trip. It's very unpredictable.

I replaced my 1997 mini-van for the Prius. I chose the Prius because:
1. I'm still getting better gas mileage than almost anything else I could drive
2. I can fit clients comfortably in the Prius; a common comment is how spacious it is inside
3. Because I do use the vehicle for my business, having one that could produce zero emissions at times was important to me (as I mentioned, I have kids)
4. Simply, it feeds my needs ~95% of the time (there are times I wish I had more luggage capacity with the car full, but the car's hatchback capacity is not really the issue; it's my tendancy to overpack )
5. The Nav, bluetooth, etc., are essential to my business needs

An unexpected benefit (for my business) is that the car seems very hi-tech (ok, it IS) to my clients - it kind of completes the package, since I do listing presentations on my laptop, use a smartphone, try to do e-newsletters instead of bulk mailing, etc. Several clients have commented that I seem to be using the latest technology in my services. I will say that (and this is a generalization) it seems that younger clients (<50) seem more impressed that I drive a hybrid than older clients.

[LanceinOregon]

Wow, mileage for my 2007 Prius just jumped 4 MPG this week! I have gone from 42 MPG the previous week, to 46 MPG this week.

Two things have happened in the last week:

#1: The weather has been way warmer. Highs have been in the low 60's, instead of high 40's

#2 I fueld up, and noticed a BIG 12 cent increase in the gas price. Could I be getting a new blend of fuel now?

In any event, with this new 4 MPG increase, I am now quite happy getting 46 MPG

Lance in Orygun

[CryLakEl]

I got my 2007 Prius a month ago, and was concerned I was only getting between 36-38 mpg
on my daily 30 mile roundtrip commute. Finding/reading this article was priceless. It answered
so many of my questions - thanx!