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

I have a 2017 on order an ill do the same. 1k, 5K and 10K

 

'12 v 33k miles. 42MPG average.

What has surprised me is my MPG at highway speeds is better than EPA. Recent trip to the mountains of NC with 3k elevation change and coming back in partial fog and rain (which means the tires are pushing the road water away which lowers MPG) (2 passengers plus full trunk of luggage) and I got 43+ MPG on the 400 mile round trip mostly at 60-70MPH with occasional oops 75s. Now granted I'm not a speed demon and will run a few miles under the speed limit when no other cars would be inconvenienced. But at least one '12 v does get EPA plus MPG and this at speeds higher than EPA uses.

I love stopping for a bathroom break and getting filled up with $8 of gas.

2 more PSI than the manual specifies. ECO on 100% of the time. No special tricks but I do try to watch several cars ahead and use that in my acceleration/deceleration plans. No mods. Original 16" Michelin tires. Not a stop light laggard.

 

low to even mid 40's mpg all summer this year. Friend bought a brand new one after seeing mine, and he's at 43 average since May.

 

Yes, a 3.70 axle ratio in the 2012 model- and 2017 shows it's now 4.11 axle ratio- I searched on Google, "2013 Prius v 4.11 axle" and it turned up positive hits-- did Toyota change from 3.70 in 2012 to 4.11 in 2013?-- is that good or bad for the MPGs?

 

Assuming the CVT provides the same output ratio, a higher numeric axle ratio would improve acceleration while decreasing mpg. The problem is the axle ratio is not as important as the effective final drive ratio which is the combination of the CVT gearing and the axle ratio. Since the CVT can provide "overdrive" ratios of perhaps 0.59/1 (rather than 1/1), the overall effective ratio is considerably less than 4.11 and could be 2.43/1 (4.11 x 0.59). Bottom line is that changes in the CVT programming or actual parts in the CVT could have resulted in the same effective gear ratio in the 2012 or the 2013 or the 2017. The official EPA numbers are the same for all years.

 

I retired from the Chrysler Transmission and I can verify that the company seldom changed internal gearing on their FWD transmissions - they used a pair of match gears to adjust final output gearing to some degree. For example, a transmission for the old 3.3L engine had 200 rpm higher engine speed than the 3.8L engine at 65mph. A person would need to do a speed run with a 2012 v and a 2013 v using a OBDII scanner to find out what is going on- I wonder if Toyota dropped in some engines built for the regular Prius (3.27 axle) into the Prius v in 2012 to keep up with the backlog of orders-
I found just such a rpm test on a Prius v of unknown year on youtube-

 

With the Prius transaxle, is rpm dependent not only on speed but also any and all variables: wind, slight grade variations, ambient temps or whatever?

I'm not sure, and my brain is full.

 

I guess back-to-back runs, same course, would iron out the variations.

 

Of course the v with its added weight compared to the hatchback had an adjusted final drive ratio to provide acceptable acceleration. Bigger and less aero too. But 42 for a wagon isn't bad in the real world. The CRVs of the world are lucky to get 30-32.

 

I used the Wayback machine to look at the Fuelly stats on the 2012 and 2013 Prius v-
in the summer of 2013 the 2013 model was already getting a high average of almost one mpg better than the 2012 model, which still holds true today. I think that switch to the 4.11 axle did help the fuel economy. It's disturbing to see the 2016-2017 models with such poor averages. Don't they have the same new battery design as the regular Prius? The newer models mpg averages don't look at all like the 2012 and 2013 models did when they were a year old on the Wayback machine website.
website example: Toyota Prius v MPG Reports | Fuelly

 

Maybe they something behind the scenes to protect battery better, at expense of mpg??

 

The new larger Honda CR-V was the first Honda designed from the ground up with aero in mind, complete with active grille shutters and a 1.5L engine that develops 190hp with 34mpg highway. It also has a CVT transmission, electric steering and all the latest safety systems. If that was not enough, overseas they are selling a hybrid version with a 2.0L that is rated at 50mpg. Right now it's in the Chinese market and is now being introduced in Germany. It will be interesting to see Toyota's response, I would assume in the RAV4 line.

 

Maybe, but since many new car buyers don't keep a vehicle past 100,000 miles, I don't see how a longer battery life is a better than high mpg.

 

i don't think the newest v's have the gen 4 lift back tech yet.

 

if so, and it makes sense, I hope the fuelly mpg numbers on the 2016-17 cars is an just an aberration.

 

I drove a CRV 1.5T and a RAV4h back to back yesterday. Much preferred the Honda for multiple reasons. In the end, decided not to buy this season.

 

Need to keep this page active.
I never got above 37 mpg in my 2014 v no manner how I drive. Change of tires no difference.

 

how will that help?

 

Is that as displayed on the instrument panel or via a multi-tank spreadsheet/fuelly calculation?

What are your typical drives like? (Length, miles, speeds, grade, HVAC on, Auto set, ECO mode set, load in the car, type of tires, tire pressure, etc)

What model car (and thus what size of tires)?

Fuelly's average is 40.2 so you are ~10% lower

 

@kirill626,

If you ever return to this post or are active again, I think I may have discovered why your Prius v's were getting poor mpg's and behaving like "trailer Prii".

I've experienced something very similar in my Gen 2 Prius.

My final post is a work in progress but you get the just of it with the above link. I talk about your low mpg thread in my post above but accidentally linked to a different post so don't get confused by that.

Basically I think one of the ECUs needs to learn certain parameters based on commute style to trigger the ECU State that allows EV mode to be used aggressively. And this ecu state will be reset everytime you do a 12v disconnect. But once it learns the ECU state it doesn't forget until a 12v disconnect.

I'm trying to prove this exists but I can't get the LEARNED State to reinitialize in my Prius again despite being able to in the past with a specific commute. So I'm not 100% sure what triggers the LEARNED state at this point but I believe commute is still at least a factor.

Your input would be greatly appreciated!