Consumption screen...

[azzieo]

I'd like to state from the beginning, that I don't mean to piss off the old(er) members of the board, but just wondering if other people find that odd:

I took a 10 mile trip this morning... first 5 miles took 5 mins to drive to the ramp, accelerate on the freeway, and then hit the traffic.... the next 5 miles - creeping away for 25 mins.. at the end - I look at my Consumption display and I see one bar at ~25mpg and 5 bars at ~75mpgs. Great!!!.. This visual with mostly high yellow bars looks like 66.67 avg mpg for these 30 mins!!!

Well - I'm no math god or anything but that's actually misleading visual presentation of the situation, which in fact is that I have driven 10 miles in 30 mins, with avg speed of 20mph and avg mpg of 37.5..... well - what seems like 66.67 is actually 37.5.

...and before someone jumps on me I'd like to state that I'm NOT complaining about 37.5, and that I DIDN'T enjoy my ride LESS, and I will still try to convince everyone I know that Prius is the greatest car on the market today....
BUT,.. the Prius has a computer that already has the really relevant data about my trip - the Avg.Speed., so it's mind boggling to me, why can't I see that information. The simplest thing to do is to at least put the miles traveled in those yellow bars, for every 5 min interval, which will give me some perspective of what I'm actually seeing.

Also - providing parallel data about AVG MPG and AVG SPD is the ONLY really relevant information, which would help me understand the optimal driving pattern for a given route... the 5 min chunks mean nothing unless I remember in my head what speed I was driving 5-10-15-20-25 mins ago, which is .... well... needless, if the computer already has that data, but just doesn't want to display it... bad computer bad bad bad..... or just another bad UI.

[monkeypox]

Hi
Well as for the comsumption screen, I have found it is not very accurate. When I fill up I check the screen and then break out the calc and do miles driven and amount of the good stuff I put in my tank and some times it is 10-15 MPG off. Now my calc is not wrong so what is the deal with the screen???? does it take in account what values u set up for the nav sys as in highway speed u set and city spd???? any way that is a monks 2 cents
Cheers
Monks

[efusco]

miles per gallon per 5 minutes....it is what it is. We've always said, all along, that the Consumption graph is only useful if you're traveling a steady speed. Any stopping, any significant speed changes and it's not an accurate representation of what you do.

Those of us who have CAN-View now have an MPG per mile readout and it is, I agree, much more useful.

[curtissac]

<div class='quotetop'>QUOTE(monkeypox @ Sep 1 2006, 04:58 AM) [snapback]312648[/snapback]</div>

Hi
Well as for the comsumption screen, I have found it is not very accurate. When I fill up I check the screen and then break out the calc and do miles driven and amount of the good stuff I put in my tank and some times it is 10-15 MPG off. Now my calc is not wrong so what is the deal with the screen???? does it take in account what values u set up for the nav sys as in highway speed u set and city spd???? any way that is a monks 2 cents
Cheers
Monks
[/b]

The MFD consumption screen is probably correct. I would say that it is correct, but suppose there is always a small chance (really small chance) that something is wrong with yours.

I would bet that you calculator is also correct. But you are probably, unwittingly, giving the calculator bad numbers.

The problem with trying to calculate tank-by-tank gas mileage with your calculator is that you don't have a fixed capacity fuel tank. The Prius' fuel bladder capacity can vary by up to a gallon depending on temperature and other conditons. A variation of a quart or so happens all the time. When you drive a car with a small fuel capcity and 50 mpg efficiency, a one quart variation could show up as... 10 to 15 mpg when you try to calculate mileage at each fill up. Even with a conventional tank, when the pump shuts off can vary a little - but the bladder throws more of a curve ball at you.

I would suggest that you compare you calculator figures against the MFD over several tanks. When you average the two, you will probably see very close numbers.

Remember that the MFD is getting its data from the fuel delivery system. That system is very accurate - metering fuel to the injectors down microliters to keep the engine running right and emissions under control. I have no reason to think that the consumption numbers on my MDF are anything but dead-nuts accurate (or at least far more accurate than I could be at the gas pump).

[kimgh]

<div class='quotetop'>QUOTE(Curtis SAC @ Sep 1 2006, 08:53 AM) [snapback]312767[/snapback]</div>

The MFD consumption screen is probably correct. I would say that it is correct, but suppose there is always a small chance (really small chance) that something is wrong with yours.

I would bet that you calculator is also correct. But you are probably, unwittingly, giving the calculator bad numbers.

The problem with trying to calculate tank-by-tank gas mileage with your calculator is that you don't have a fixed capacity fuel tank. The Prius' fuel bladder capacity can vary by up to a gallon depending on temperature and other conditons. A variation of a quart or so happens all the time. When you drive a car with a small fuel capcity and 50 mpg efficiency, a one quart variation could show up as... 10 to 15 mpg when you try to calculate mileage at each fill up. Even with a conventional tank, when the pump shuts off can vary a little - but the bladder throws more of a curve ball at you.

I would suggest that you compare you calculator figures against the MFD over several tanks. When you average the two, you will probably see very close numbers.

Remember that the MFD is getting its data from the fuel delivery system. That system is very accurate - metering fuel to the injectors down microliters to keep the engine running right and emissions under control. I have no reason to think that the consumption numbers on my MDF are anything but dead-nuts accurate (or at least far more accurate than I could be at the gas pump).
[/b]

I concur. On my recent 2000+ mile trip in the Prius, I kept the overall MPG for the whole trip. and achieved 49.8 MPG. I also kept all my gas receipts and, just after the last fillup, I divides the total miles traveled by the total # of gallons purchased for the trip. That came out at 49.96. So I totally believe in the accuracy of the display.

[Beryl Octet]

<div class='quotetop'>QUOTE(efusco @ Sep 1 2006, 08:09 AM) [snapback]312661[/snapback]</div>

miles per gallon per 5 minutes....it is what it is. We've always said, all along, that the Consumption graph is only useful if you're traveling a steady speed. Any stopping, any significant speed changes and it's not an accurate representation of what you do.

Those of us who have CAN-View now have an MPG per mile readout and it is, I agree, much more useful.
[/b]

I think a view that showed miles per gallon per 5 miles, or MPG / miles would be useful. I like the bar showing instaneous mileage while I drive, but with stop and go etc., I don't find the graph that useful. I really wish the energy display had a bar on the side, then I'd probably stay on that screen most of the time.

[Sho-Bud]

The consumption screen is correct, but you can't use it to calculate the average consumtion of your trip.
Because you don't know how many miles you drove during that 5 minute period.

[Ichabod]

Stopping looking for things to find fault with in your fabulous new car, azzieo If you didn't have MPG/5min display then you wouldn't be able to fake some awesome-looking screens of full bars!

[azzieo]

<div class='quotetop'>QUOTE(Ichabod @ Sep 1 2006, 01:04 PM) [snapback]312858[/snapback]</div>

Stopping looking for things to find fault with in your fabulous new car, azzieo If you didn't have MPG/5min display then you wouldn't be able to fake some awesome-looking screens of full bars!
[/b]

Thanks for the advice...

[qbee42]

How about a 3D chart showing mileage and distance in five minute increments.

Tom