Careful, Indy!! I'm not certain where you get the argument that you are "doing better." Sure, you have a higher average speed, but Wayne's FE is still considerably better. Ask him about his commute -- miles, stop lights/signs, traffic -- and then see if you could find a way to better it! We all yearn for a bit better. I've said more than once: Oh! What I'd Do to get a Longer Daily Commute!
It depends. Yes, you are partially right about the average MPH, but if someone averages say around 30-35 in a full tank, we both know that it likely represents real-life commuting with mixed city and hwy driving with some stop lights and stop signs. Who in the world will drive 40 MPH on cruise control for a full thank just to get a record MPG? In theory your point is well taken, but let's think about what really happens out there in the real world. The report of 70+ MPG from Wayne, for instance, is not surprised because he was commuting at 20 MPH on average, so he was using the ICE a lot less, or do you think he actually set the cruise at 20 MPH and drove a full tank on that speed? I don't think so...
That's why I made this statement. Lower speed is a BIG factor in high mileage in my opinion, maybe the biggest.
I can guarantee if I drive my same commute right now at lower speeds, (20 MPH like Wayne) I would get 70+ or maybe 80+ of tank MPG easily. The problem is: I don't want get late to work and I go home at lunch time in a very thigh schedule... so, not happening. There is no question that MPG numbers at 20 MPH is somewhat useless...
Just as a important note: I'm not trying to compete with anyone here regarding MPG readings, although being able to hypermiling and see good results is rather satisfying. We are all WINNERS just by being Prius owners. My point is: people recording MPG data should take into consideration other factors like: tank vs. short trip mileage, MPH, weather conditions, cargo load, etc. We have to do our best to avoid false impressions of outstanding MPG readings, so newbies or those still learning hypermiling don't get frustrated with our numbers. That's all I care.
In engineering we call it 'managing user expectations' and that is why I've tried to focused on the baseline vehicle performance. Bob Wilson
I've been lurking here for several months and have found it to be interesting. I picked up my Gen III July 2nd and have rolled up 4500 miles so far. I just filled up this afternoon with 589 miles using 9 gallons. The display reads 69.2mpg's and I calculate at 65.4. I've seen a 5.5% gap on each fill. But who's complaining. This is a mix of all kinds of driving where I take it easy and some times not so easy. I love to hear the squeal of the tires now and then. I've never got below 58mpg's.
waaaaaaaaaaaaaaaaait just a minute here....I've been assuming that because I've only been able to put 9.5 gallons in, that the "empty" indicator was firing early and that I still had ~2 gallons in the tank. You're telling me that it's the TOP of the tank that is empty when I "fill" it to the first click off, even when going at a low flow rate??? :shocked:Why does the gauge read full then? (as a practical matter, if I were designing it, I'd want it to err on the side of the user having MORE fuel than they think they have...but that's just me Ms. Glass Half-Full :tea:
What's the point of posting photos of the MFD display? The G3 MFD is so far off that what they should really be taking pictures of is their manual mpg calculations.
you remember how to do this ... RIGHT? top off you gas tank.... to the rim or until you can't get another drop in the tank. Don't spill a drop Take the mileage down or write the mileage on the ODO. Do your thing.. drive drive and drive til the refuel light comes on. Top off you gas tank to the rim or to the point you can't get another drop in the tank How many gallons did you take to fill the tank? Then do the math. miles traveled divided by the gallons used. Well ah.... MPG PS: this first click or shut off is not the true top off. I can get a gallon and a half more in the tank after the first click off. You need two absolute top offs to get the real MPG. On my CR-V the first click off is very close to the absolute top off.
I believe I have put at least two gallons more than the first click, Do so at your own peril of course. My personal observation of other cars that I have removed the tanks from is that there is a bump on top of the tank where the vent is connected, and your not filling fuel up in that bump, the shape of the tank prevents that. I would assume the Prius is the same way. But I do believe it's possible to damage the system by filling the tank completely full of cool fuel and allowing it to sit in the sun and expand. I see aircraft venting fuel on the ground all of the time from this. I have seen documentation that GM intentionally has their fuel indicating systems calibrated so that by the time the gage is indicating 1/2 much more than 1/2 of the fuel has been used. They do this because most people refuel with a lot of indicated fuel remaining and therefore they are not getting as much use of the tank as they could. I assume this may be an industry standard? All vehicles that I have exhibit this. I know a person that is convinced that her Tahoe gets worse mileage in the last half of the tank, so in order to get better mileage she refuels before the gage indicates 1/2. You can't make that up, it's too stupid, but she is convinced.
The air gap in the top of the tank is called ullage. It's designed into the tank to allow for thermal expansion.
? I think most of us have the similar situation where the MID numbers are about 5% or so higher than the calculated mileage. Right?
