No improvement from Gen 2

I also upgraded from a Gen 2 Prius (2008 touring model) and also miss some of the sweet storage areas that have evaporated in the Gen 4.
I can tell you that I had a calculated total of 50.52 MPG for 122,806 miles in my 2008 Prius and so far have a calculated 61.30 MPG for the first 36,621 miles in my 2016 Prius. Same driver. Same spreadsheet. Same location. Similar driving routine, although I have recently retired and I do think the 2008 had a more advantageous-for-high-MPG daily routine.
I'm sure that you have tried all of the easy tricks like raising your tire pressure - so I cannot understand what could be driving your issue.

 

Your driving habits are the same and will result in the same MPG. When I went from my Gen 2 at 55-60 mpg to my current Eco 2, I also went up to about 70 mpg.

 

4 months of winter driving, right? That drops my MPG by around 15.

 

Firstly, you can't compare a Gen 2 with a Gen 4 as far as driving is concerned. I tried a Gen2 (and later a Gen3), and wouldn't buy one because it wasn't a particularly good drive - specially at the price.

Secondly, re MPG - have you kept full records of fills of your cars - over the same period of time (one fill can be deceptive as you can't guarantee that it's filled to the same level - particularly on a Gen 2 with the bladder.

And, did you do manual calculations on both cars - or just the Gen 4?

I can't see it getting only 46-48 MPG, mine does much better driving it "normally" - unless something is wrong, low tyre pressures, sporty tyres instead of ECO tyres? Or, because it is a much more sporty drive, driving it harder or faster?

 

the epa test and your driving style may not be compatible.

 

No my driving habit was the same. I generally drive slow and hypermile it when I can. Gen 4 is just better in fuel economy overall. I get about 65 mpg going to work, and on the way home I get 90 mpg. Gen 2 was like 55 and 70 respectively I believe.

I came from 4Runner and before that a Supra. I had to change my driving habit - tickets are expensive in California.

 

I checked my Gen 4 (with new tyres) against the GPS - the speedo was reading 3km/hr fast at 100km/hr, but the odometer was so close I couldn't fault it. Now, with 40,000km on the tyres, I might re-check odometer again. The dashboard display of l/100km varies - I've had between 5% and 11% optimistic on tanks, generally about 7% optimistic - which, I suppose is to be expected, as it's not a carefully measured figure, but is computed by the car using various inputs - though being optimistic is something I've noticed on every car I've checked.

Your figures for MPG - have they included every fill - or just one or 2?

 

Judging by Fuelly, there was a modest increase in mpg going from 2nd to 3rd gen, and then a significant improvement with 4th gen:

Toyota Prius MPG - Actual MPG from 7,660 Toyota Prius owners

 

By the spreadsheet, so for my 2019 awd-e LE is averaging 4.2L/100kms (56 us mpg). I have not yet gone though a winter, which will change things, as I've found that the heavy rains we get here and standing water decrease fuel economy somewhat.
I find that the stock bridgestone ecopia tires are affected by the rain more than I thought they'd be; my next set of three-season tires will be rated excellent for rain.

 

That's disgustingly good. And I suppose you're not even trying hard...

What does the display show, by the end of a tank? On our third gen it's invariably 0.3~0.4 lower.

I was trying my durndest today, new tank, going back and forth to the landfill with bundles of blackberry vines. Purposely going the long way round, to avoid a hill climb. Managed to get it down to 4.5, rolled into the garage at 4.6 I think. Which means at least 4.9 calculated.

New 17" tires might be a factor, and there was a software update

 

Actually, I am trying pretty hard to get good mileage; I looked up videos of how to drive a Prius, as I've never had one before now
So far mine's 0.1-0.2L/100kms optimistic, but I'm waiting for at least ten tanks to call the average error of the dash readout.

My last tank, which on the spreadsheet showed 4.0/100, showed 3.9 on the dash:

 

now your cookie'. gotta overlook a lot of faults to achieve 50 mpg's

 

Is yours a Li-ION battery - they're more susceptible. I'm pleased that TOYOTA Australia has only offered the NiMH battery.

Lane Detection - I love it - yes, it occasionally annoys, but I'll put up with that for the time when I NEED it. I'm certain my insurance company wouldn't be impressed if I turned off a potential life-saving (and accident repair saving) safety item - and it cost them big €€€. In fact, I'm sure they'd use that to invalidate a claim in a heartbeat.

Yes, I turn if off on a narrow winding mountain pass, but never on the Motorway which is the majority of my driving.

 

I turn off the lane detection beep, as I commute over a twisty mountain pass, and it'd beep all the time. Yes, the side hinge console lid is annoying I find that the sliders on the sun visors do a decent job. I hate where the heated-seat switches were moved to for 2019.
My tenth tank got an average of 3.8L/100kms (61.9 us mpg) by the spreadsheet, and that's with awd. I'm damn happy
My dash seems to be 0.2L/100kms -- 3mpg -- optimistic; I wish that could be adjusted.