Living with the Prius IV rather than a V?

I've never read anything that indicated it does. The only difference in the chassis as far as I know is the steering mechanism.

 

You say it's ~1 mpg, so do you know the actual unrounded numbers? Rounded to the nearest 0.1L/100km, the EA specs show 3.9L/100km for the 15" wheel Prius and 4.0L/100km for the 17" wheel Prius. This translates into a 1.5-1.8 mpg difference so you'd still expect a small difference not attributable to driving habit/conditions. The actual difference could be less or more due to the positive or negative bias from rounding (e.g., the actual numbers could be 3.86L/100km and 4.04L/100km, respectively).

 

Well, i watched him drive...not that much different than me. I am sure that there were minute differences and so on, but his IV easily gets 1-2 mpg better than me. Don't get me wrong, i still love my V...this difference would not have made me change my mind.

 

Well, to me, this falls into the rounding error category, not a "mileage hit" as you described it.

 

Of course I know the unrounded numbers. I was trying to spare everybody of the minutia...but since you insist.

The UK specs are 72.4 (combined) MPG for 15" and 70.6 MPG for 17" (naturally, these are imperial gallons, which are equivalent to ~1.2 US gallons, and use the UK MPG standard). Take the % decrease for 17" and multiply by 50 MPG (US EPA), and you get 1.2 MPG:
[(72.4 - 70.6) / 72.4] * 50 = 1.2

My point was, any of these MPG differences are what I consider to be a rounding error.

 

But these figures are back-calculated from the metric figures of 3.9L/100km and 4.0L/100km rounded to the nearest 0.1L/100km, which is the source of the rounding error. I'm asking whether anyone knows the unrounded metric figures.

 

When I say it's a rounding error, my point is, that whether it's a difference for the 17" wheel cars vs. the 15" cars of 1 MPG, 1.2, 1.5, etc., (vs. a 50 MPG base), that's a rounding error in my mind. Manufacturing variances, driving with a nearly empty tank vs a full tank, or any number of other variables would create as much of a difference. At some point, it's mental masturbation.

 

May I suggest that if handling is a concern, you avoid the solar roof package, which presumably adds considerable weight to the vehicle at the roof, where it raises the center of gravity.
As for choosing between 15" and 17" wheels, without driving and comparing, I wouldn't assume that the 17s handle better in all respects. I had a car with 16s and 17s and the car was more agile with the 16s.