Break-in period mileage - normal?

AS for miles per tank.... My dealer filled tank, I wanted to break 400 miles anyway, so it was down to the last pip and I filled it up. It took about 9.5 gallons. Which put me over 40 mpg, which I was happy with then. Next time, I filled when I was well into the 2nd from the last pip..... about 9 gallons..... So I have yet to use up those 11.5 gallons; therefore being hard to tell what I'm actually getting per tank.

 

My first tank (dealer filled) was like this:

- MFD = 43.x mpg
- Fill = 9.8gal
- Trip = 360 mi
- Calc = 37.x mpg :huh:

However, I just read every thread on the topic of MFD vs. hand calculated mpg, and I'm probably going to just 'trust' the MFD from now on. While I care about my MPG, I don't have time to obsess about it. The relative trend compared to the last tank is what matters so I can see if my air filter is clogged or the tires need air.

Even though my first tank wasn't that great, it's still twice as good as my old 20mpg BMW! My commute is also challenging for the car with 15 miles each way and lots of hills & lights - 45 minutes during rush hour. It's still summer here in San Diego and I usually have to keep the AC on, so I'm sure once things cool off I'll be able to reach the magical 50mpg mark too.

In my case if I assume that the dealer only put in 8 or 9 gallons in the first place, that already pushes me up to the range that the MFD is giving me. 30 miles into my 2nd tank I'm at 48mpg on the MFD.

Don't worry, have a homebrew! :lol:

 

<div class='quotetop'>QUOTE(Ari @ Sep 8 2006, 04:34 PM) [snapback]316617[/snapback]</div>

I was hoping to do a comparison like you did between my calculated mileage and the MFD mileage, but my wife borrowed my car and accidentally reset the MFD mileage about 1/3 of the way through the tank. Oh well, I guess I'll have to try it next tank. I'll have to wait well over a month at 46mpg.

 

I gave my '06 Prius a 5,000 mile "break in". At that time, I reset all of my stats and have allowed my MPG stats to accumulate on the OSD since. Over the last 5,700+ miles, I'm averaging 46.8mpg. I'm pleased with that. I do recall, though, that my first tanks of gas were giving me only around 32 to 36 mpg, so don't feel alone.

In my own humble opinion, about the only correct statement in the EPA blurbs is that "mileage may vary"...on that, I believe we all can agree!

 

<div class='quotetop'>QUOTE(YvesKlein @ Sep 2 2006, 02:38 PM) [snapback]313184[/snapback]</div>

I, too, live in LA and our Prius is only 1 month old. We, too, got 'only' about 350 miles on the dealer filled tank. But, when we filled up our first time, the car only took 7.5 gal.

I figure the dealer either didn't top the tank, we filled up sooner than we needed to (so we can get a feel for the tank gauge), or the car had more than the usual power up/down while sitting in the lot.

So, my suggestion is ignore the total miles you get on a tank and simply concentrate on MPG.

 

Yves,

We also have a new Prius. My wife commutes about 18 miles each way, combination highway and city driving. The first 1/2 tank from the dealer averaged 43 mpg. The second 1/2 tank averaged 48 mpg. The third 1/2 tank is averaging 50 mpg. My wife ignores the consuption and energy screens, but can tell you whatever you want to know about the stereo. In other words, her driving style has not changed at all. I have checked the computer's estimate of mileage against the miles/gallons added each time and the numbers are close.

Also, please consider that in a Prius we are very aware of mileage compared to how we were in other cars. When I compare this mileage to the real world mileage we got on her Corolla and my Sienna I am convinced the Prius was a good choice.

 

Just put in my second tank of gas today. Averaged 44 MPG there. But considering A) I still have under 800 miles on it (if someone is calculating, both times I filled up when it was about 3/4 empty); 90% of my driving is to various stores no more than 7 miles away, and when I do highway driving, it's on twisty hilly roads (getting four bars in a row of 25 MPG was worth it for coming home and getting three bars in a row of 100 MPG).

I don't play the "Max your MPG" game, but I notice I do drive slower on the highway (at least, when I'm going uphill or on a straightaway), and I put more air in my tires when I filled up today (was 35 PPI cold, now 42 warm; I'll have to re-check tomorrow what it is when they're cold again so I'm comparing apples to apples).

As someone who always bought fuel-efficient cars (my last car was an Echo which I loved, and before that a Geo Metro that I loved even more, mostly because I had to go to The City often and would always find parking spots that I wouldn't have been able to get if my car was a couple of inches longer), the Prius is the most fun car I've ever owned. So far.

 

The only accurate way to calculate MPG is to keep a running total of miles driven and gallons purchased. It's not going to work for one or two tanks of gas. Like this:

Miles - T. Gals - AVG MPG
410 - 8 - 51.25
700 - 15.5 - 45.16
1270 - 26 - 48.84

etc.

Since the gas bladder fluctuates in volume, it's not a good way to calculate mileage.

 

Feh. That would require me to remember how much gas I bought at each fill-up, which would require me writing it down somewhere. That's too much work for something I frankly don't care about.

 

I'm a new owner and drive primarily highway and have been averaging 50-ish, from the beginning.

Variation factors, I notice are whether it's a long or a short trip (due to engine warm up, the computer almost never shows me getting more than 25mph during the first 5 minutes, and then it jumps to 51-52) and traffic if I'm on local roads. Interestingly, sometimes heavy traffic can be a boon, if I can keep the car in stealth mode, other times, where the engine is on or off, it's a hinderence.

My observations for fellow newbies -- the fuel guage is inaccurate. This is the biggest disappointment I've seen so far. On two successive fillings with three bars left. I took 7 gallons once and 4 gallons the next time.

Second observation -- even if you drive exactly the same, you will find tank variance. For example, even with only a couple of fill-ups. Once I went to a full serve station -- they topped it off (my mileage was in the mid 40's), next time, I was at self serve, I didn't top it off, and had a tank mileage of 59. However, the difference has little to do with performance of the car, IMO, more like the service station got an extra half gallon into the machine (which affects the math). Even with self serve alone, there's going to be some variance as to how full you get the car.

So, my guess is that anything more frequent than monthly averages (total miles/total gallons) will contain an unavoidable variance. Since I'm thriled with the car under all circumstances, I've decided that the best thing to do is not obsess about what I do in any one trip or any one tank, and just enjoy the car.

 

<div class='quotetop'>QUOTE(Stev0 @ Oct 4 2006, 09:42 AM) [snapback]327805[/snapback]</div>

I just print out the receipt, but to each his own.

 

Having owned an 04 and now an 06:
My 06 bumped up mpg around 2500 and then about 8k miles. Started at 48mpg and now get about 51-52 mpg. Same route, same temps.
I had 88k on my 04 so there was no driver breaking with the 06.

 

My first tank was mid 30's when I purchased the car in March. I now get consistent mpg ranging from 52 to 57. This will be my first winter so I'm a little fearful of how cold temps will affect my mileage. My higher mpg was realized within a three month period. I hope that if your patient, you'll see the same trend. There are plenty of threads here to assist you with driving techniques to benefit same. Good luck and enjoy your car!

 

My 2006 Prius is about three months, with 4200 miles on it. I've noticed that the mileage has dropped off some. I made three identical trips to Temecula from Anaheim recently. The first trip averaged 54 going out. The second 48, and the third 42. Same freeway and nearly identical traffic. I do run the A/C comstantly and don't really baby the car. The 5000 mile service is coming up soon, so I'll bring this up with the Service Manager.

 

I've got 1800 miles on my 2006 Barcelona Red ... My lifetime mileage according to the MFD is... drum roll please ......... 56.3mpg!!! The unfortunate timing of my purchase means that the onset of winter weather will likely negate the "break in boost" we are supoesd to see around 2000 miles, but i'm still quite happy.

 

<div class='quotetop'>QUOTE(YvesKlein @ Sep 2 2006, 01:38 PM) [snapback]313184[/snapback]</div>

I've had my 2007 Prius for about 2.5 weeks. I do mostly city driving. My first tank averaged just over 40 mpg. I filled up at about 2 bars and the car took 7.7 gallons. That gas bill put a smile on my face!