While talking with a friend of mine, who owns a honda hybrid, he said that what his display told him his MPG was and what he calculated THE OLD FASHION WAY were two different things. He was actually getting far less than his display said. I have yet to try this (I'm an impatient guy) ... has anyone compared the milage stats in this manner? Also, I have had my car now for about 400 miles... will my milage improve as the car breaks in, or am I there already?
I haven't found any significant difference between the display and my calculations. Everyone says that after you have driven about 5000 miles the car will be considered broken in and the mpgs will improve. I just hit 4800 and noticed an improvement after about 4600. Hang in there, it will get better. In the meantime, be sure to check your tire pressure and learn the fine art of coasting. There are a lot of discussions here on getting better gas mileage. Check them out.
The difference between the display and calculator after 1 year and 12,000 miles was about 1 mpg. The display was higher.
At 9000 miles my delta is 1.3 mpg. See my graph. The display is more consistent tank to tank. The calculated varies over a wider range (bladder changes, different gas pumps, etc.). Over time they end up within a couple percent, which is pretty good. The weather has been warming in Texas and my latest tank was over 57 mpg. My two lowest tanks were highway trips to west Texas with a full load in the car and a cold headwind in both directions! www.enerjazz.com/prius
24k+ miles, difference between the two is less than 1MPG. I strictly follow the computer figures for figuring DTE (Distance to Empty) and have yet to run out of gas. -m.
I think if you calculate one tank, there might be a noticeable difference. Over the course of many, many miles and tanks, the difference is trivial. I won't say "nonexistent" but almost statistically insignificant. Like John1701a and EnerJazz, I invite you to look at my spreadsheet (in my sig) and see for yourself that in the end, it's not so bad. [Edit] Sorry, I misspoke there. I'm not showing calculated MPG versus Display MPG per tank. Rather, I'm showing an average of all MFD MPGs versus actual miles drivern divided by gallons consumed. Still, though, in the grand scheme of things they are pretty close. [/Edit]
Thanks to everyone for your input. I was curious and am now relieved that the readout is pretty right on.
I sure wish I could agree. But my displayed verses calculated is substantially different. Can't imagine why either. (see below) If anyone has any idea, I would be open to any comprehension. TIA
Last fill-up needed 10.53 gallons where the display told me 10.00 would be more appropriate. Seems like 5.3% inaccuracy on somebody's part. I crammed gas in last time, just like this time, so either this pump wasn't accurate or I need to REALLY stick to the 10x refill rule to be safe...
I too notice a slight difference between what the mfd says and thew old fasion way, however, I also noticed that when i refueled my new prius at the pump it only took 9.059 gallons before it clicked off. This leads me to believe that I had another couple gallons in my tank. Does this sound right? I stopped for gas very soon after noticing my gas bar was down to one blinking light. How much can one drive when gas is like this? My MFD at the time said 46 mpg and i had 414 miles since my last fill up. Could I have safely driven until i reached 460 miles? Lastly, are there any other warnings i could rely on aside from the last blinking bar? Thanks! -Andrew
As with almost all above, I've stopped calculating my MPG the old fashioned way when my first 10 tanks revealed that the difference was about 1 to 2 mpg off, with the display always higher. As TonyPSchaefer said above, the numbers may be different when you compare one tank to the display, but when you average them out, the display is pretty predictable, albeit slightly higher than what you are really getting. Graz, is your difference predictable and consistent? If so, there may simply be a software glitch. You seem to have a problem that most of us don't have. And 25 points for your sign off: Limit your funding of international terrorism! Drive a hybrid.
after one year my lifetime is 3 mpg lower than the MFD. Canadian gallons in US gallons that works out to 2.5 mpg lower. Pretty close to what Dan figures. I chalk it up to bladder effect and pump volume inaccuracy.
Mine has been more optimistic than most. At current, I'm still showing a 3.4 mpg difference over the lifetime, with the MFD being higher. Mine's an 03, so I don't know what software changes Toyota may have made when they reworked the system.
I've had my Super White since 11/2004 and have driven 8,124 miles. So far the car's displayed MPG is 1.55 MPG optimistic.
I blame most of this on pump inaccuracy/flow corrected to 50F and to a lesser extent the Bladder effect.
Well for me, the numbers really don't matter. B.P. (Before Prius) I was only getting aroung 18MPG, so even if I averaged 36 MGP (twicw what I was Getting) I would still be happy beyond belief. I could sit here and complain about a 1 to 2 MPG difference but I just think of the time B.P.
