Document your MPG by doing this!

I've done quite a bit of reading on MDF mpg difference compared to calculated, so I started tracking this about 1 1/2 months ago. To date, there's been a 3.35% difference--MDF has been 3.35% higher than calculated method.

 

We bought in mid-November 2010, and I started tracking mileage in a spreadsheet at the outset of 2011. Basically recording the odometer at each fill-up, and the gas purchased. I reset Trip A at each fillup, to verify the odometer change, get the in-dash mileage feedback and to have a feel for miles-to-empty.

The spreadsheet primarily uses the gas purchase and the difference between the two odometer readings, to calculate actual liters per 100 kilometer. But I also enter the Trip A liters per 100 kilometers reading, and calculate the error.

We have the stock 17" wheels, which have slightly smaller OD than the stock 15" wheels. I would think Toyota has adjusted the odometer for that, but not really sure.

Anyway, for the year to date, we've travelled 12135 kms, consumed 605 liters, and accordingly have an overall fuel economy of 5.0 liters/100km (it's gotten a lot better of late, car braking in, warmer weather).

Average in-dash was 4.67 liters/100km, for an error of 6.42%.

 

I'll be buying my Prius hopefully this afternoon but driving style can have a huge impact. My current Subaru Legacy wagon with 4spd automatic is rated at 20mpg city but by adjusting my driving style I average 23, and by inflating my tires a couple psi over the car's recommended pressure (but below the sidewall maximum) and using pulse and glide where traffic allows, and cruise control where it doesn't, I can average 27mpg even while delivering pizza and idling for quite a while at my deliveries and using a/c. That's 35% over EPA estimates for the car and the 2003 estimates were optimistic compared to today's numbers, and this in a non-hybrid, awd station wagon with an automatic. Driving style makes all the difference. My friend struggles to get 22 in mixed driving in his 05 with a manual.

 

Take a look at the fuel consumption pole, upper 40's is a very commonly reported MPG. The histogram looks very believable to me, the data is approximately normally distributed with a mean of about 48 to 49 MPG.

Personally I get between 52 and 56 MPG averaged over a complete tank (over 500 miles) just about every tank.

See this pole: http://priuschat.com/forums/gen-ii-...l-what-mpg-you-getting-in-your-gen-2-a-9.html

 

How do I get accurate mpg figures with over size tyres, eg 205/55/16 witch have fewer turns per mile so that the odometer under reads the distance that I drive. I could do a calculation odo miles divided by gallons used plus say 2% but how accurate is this going to be. The only sat nav I have is the one fitted in the Prius can I use this to give me accurate distance covered.
It could be that the MFD display will now give an accurate MPG reading since on my old tyres 195/55/16 and 3mm of tread had the display over estimating MPG by about 2.5% over calculated MPG.

 

What are Toyota's real-world claims that you want to see updated? I've seen them advertise only EPA figures. I don't want to see them go into the legal grey area of heralding other, over-optimistic 'real world' figures.

This was the Taylors, visiting from Australia for a special VW-Shell promotion. Wayne Gerdes crushed it three months later, getting nearly 10 mpg higher in a Civic Hybrid in much less mpg-friendly conditions. I hope you have seen what he and others can do with a Prius.

Why compare a PHEV Hummer conversion to a regular Prius? Compare it to a PHEV such as a Volt (once advertised at 230 mpg) and a PHEV Prius instead.

Here is the Gen3 distribution I plotted three months ago, from user reports at fueleconomy.gov. Sorry, I didn't make an equivalent Gen2 plot.

 

Just because you don't get good fuel milage doesn't mean everyone else gets poor fuel mileage. Either your commute or driving style is to blame.

With my 15" wheels I don't even have to try to get high 40s for mpg. Even driving like it's a race car and my 17s I can get 40mpg.

 

Likewise, just because you don't get better gas mileage does not necessarily mean those that do are liars... Which is the insinuation I get from the OP's posts.

 

I don't know, maybe you should stick your head in the picture as well so we know it's really your! Can you also get it notarized?

 

That is just more 'hypermilers drive too slow' propaganda. If everyone drove like a hypermiler, I predict that traffic would decrease, and people would arrive sooner. Imagine if everyone timed stoplights, so that no one had to stop!

 

I'll take a picture of the mfd once I'm far enough into the current tank, but for now here's how I did last year, my first year of ownership. Average for the year was 52.7mpg calculated, 54.5 displayed. It would have been better had it not been for the really awful tank in December/January, when the car was in the body shop (don't ask). I primarily used the car for commuting, about 40 miles round trip, mostly highway miles on fairly level roads. Typically @ the speed limit but also plenty of heavy traffic which allowed me to P&G without disturbing the flow.

The fun thing about this chart is it really shows the "bladder issue" in action.

 

http://priuschat.com/forums/gen-ii-...enge-over-50km-l-117mpg-tank.html#post1151806

World Record so far (not me).

 

In the USA, it is illegal not to use the EPA ratings. When the EPA said 60/51, that was what Toyota advertized, current EPA is 48/45 for Gen 2. In the UK, it has a rating of 54.7 MPG in US gallons. In Japan, 83.5 MPG.

I average 42 MPG in winter and 45 in summer, 48 in spring and fall. But look at my Avatar, all those other Prius are empty, you can see right through them. Mine is full, the weight pulls my MPG down.

I too, am a geezer, 40 years of 'bad' driving habits hold my Prius MPG back in ways I may never get used to changing. If one of these whippersnappers visits you and gets 50+ MPG in your Prius, how will you feel?

 

how do we know that's you tony? do you have a picture of you holding your picture?