Possible undiscovered performance and MPG issues with Prius v (lowercase v)

If you looked at my recent fuelly history, you'd see the 63 and 25. As soon as I posted the first one, I knew the next would vary that way. Maybe I even suspected when the first shut off happened.

Of course the nozzle angle had something to do with it.

And these weren't big fill ups, I tend to refill at about the 5 or 6 gallons needed point. So even a half gallon would have a big influence in the calculated MPG.

The state cares not about the shut off point beyond safety, they do care about the accuracy of the billing and in both cases it was spot on.

This wasn't the only time such a wide disparity occurred back to back.

My only point in posting was to suggest that averaging over several tanks probably gives you a truer readout of your MPG than a single tank calculation would.

 

Without a doubt

 

Correct. Be sure you're dividing total distance by the total quantity of fuel consumed in that distance. Some people try to figure average mpg by averaging a series of mpg results. That method won't yield the correct average---although it might be close if you buy close to the same amount every time. A similar precaution applies when you're calculating the average discrepancy between actual fuel economy and the number shown in the display.

 

Understood, and you are absolutely correct. Long term average is the way to go...


I though I read somewhere that fuelly can now disregard the outlayer really really high (possibly a mistake in input numbers by user) as an option to get more average and appropriate data?

I do remember seeing a persona on fuelly that was consistently low to mid 40's with a crazy high tank for one that was in high 60's or 70's? I should have but didn't notice the miles driven on said "tank" Maybe he filled up just prior to a record short trip, then filled up again and posted his fuelly numbers? But that shouldn't skew the average as it is an average? Right? Either way one can't consider that a "full tank average" but it will get imputed into fuelly...

Kinda akin to me filling up prior to this trip:


Then refilling and posting this average (very abnormally high due to perfect conditions and rolling hills) as my "tank full" average, when it was really only for a trip...

Either way.... Let's roll on...

 

^^ just in case CR94's point is not beaten to death yet,
he is pointing out that a weighted average is required for fill-ups of different amounts.

Or, for the lazy amongst us: total_miles divided by total_gallons

 

thanks, i thought i was gonna have to get off the sofa for that one.

 

And I agreed. Read first line of my last post....

Heck I keep all my gas receipts and break it all down in all the ways I can. Lol. So I understand.

Was just reitterating that short trips can't be used for "tank averages" as it seems some folks have been claiming outrageous averages when in most likelihood it is due to an extremely high mpg trip and not a full tank average....

That's all I meant.

Goodnight...

 

Maybe the major recall on the ,,V,, will cure the gremlin some have

 

maybe it will rein in his non trailer v's.

 

With regard to the 'trailer cars', how about this: I've read about and noticed myself the change in the engine tone and power about 30 second after it has started. This is when the engine changes from the 'otto' cycle to the 'atkinson' cycle mode. It is done by controlling the valve timing. What if the 'trailer cars' have a problem with the valve timing control?

 

Can't imagine that. All uphill on the second tank?

 

Nothing to imagine, the third tank reverted to the 42MPG +/- norm.

The variation was on a small fill up with an early shut off. Think of the MPG effect of a 5-6 gallon fill up on calculated MPG if the shut off was a half gallon early.

All I'm saying is calculate over a larger sample of fillups. One allows for too much variation.

 

True, with such a small tank, even .3 gallons has a dramatic impact, the law of small numbers. My mileage the last 10 fillups is over 43 mpg, and I wasn't even trying, nor are my tires at my preferred psi levels. Backtracking over two years, breaking out the cold months, in a moderate to warm climate, my overall lifetime mileage would be at the 43/44 range, and that doesn't take into account the hills we have, which would probably add somewhere in the neighborhood of another 2-4 mpg. Geography and climate has a huge impact on hybrids.

 

kirill626,

New to Hybrids, Prius, and this forum (first post). Thank you for sharing your experience and concerns.
Looks like fun items to isolate for root cause.
Have you checked for spun or bad bearings in the wheel hub, CVT case, or drive shaft(s)?

 

Any news? I have a prius + with "trailer" effect. I also have a 2010 prius and i remember i had the same problem . I changed the rims from 17 to 15 and the oil from 5w30 to mobil1 0w20. The car changed alot. Yet the most important and strange change was when i exchanged the 0w20 mobil 1 to 0w20 eneos....best consumption ever....
the days i"l change the oil from my prius plus (i bpught it with 5w30 ) with eneos 0w20 ....
I'll keep u posted....

 

Rehm94 I posted this just recently I have a 2012 v Three and usually get 40+ mpg. I got new all season tires in August and MPG dropped to 35 MPG. The last week or two, the MPG is back to 41.
Folks talk about the 12V is easy to measure. Are we just talking about using a DVM on the battery or test points?
I would wonder how that effects MPG?

 

Do the following : find prius without trailer , get it's VIN and your VIN and go to a program like Autodata and check if the components codes of the gearbox are the same ....
Also, being a E-cvt gearbox it's ratios are controlled by ECU. Might be the same gearbox but with different version of software. To be certain do the comparation i told u ....
If i remember well u told us u switched engines and gearboxes from non trailer to your car....nothing changed...
I think the answer is the software....

 

yes, you have to test it in the morning before driving, without opening the drivers door.