Wrong wheel/tires can wreck your MPG

This was a post from the forum Ecomodder. 

Prius 15's are better than aftermarket 17's! (Wrong wheels/tires can wreck your MPG)

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So, about a year ago, I broke down and purchased a "new to me" Prius. A 2004 with all the bells and whistles from that year. Among these was a set of 17" rims that I was never really crazy about (I just didn't think they matched my car). So after a year of driving and getting low to mid 40mpg's, I told to my wife I wanted to swap tires with her car (also a Prius, but an '05) so I could test what the difference in MPGs would be. She said she didn't care, so I could do whatever I wanted. I swapped them between vehicles. My MPG went up, hers went down. I had half a tank with the 17's, and half with the 15's, and my MPG went up to 52mpg! She took a 1000 mile road trip, and her interstate MPG went down to 38 (normally mid to upper 40's)! Apparently the rolling resistance of those 17's was terrible.
She really hated the tires, and told me to give hers back, so I did... but not before I found a set of 15" Prius rims (from a 2010) and mounted some Bridgestone Ecopias to them :-). My first tank with the Ecopias came in at a whopping 64mpg! I am going to have to check a few more tanks, since it was a half tank (~250 miles) on account that we would be leaving on a trip. We currently have my car and are traveling on twisty, turney mountain roads in the middle of nowhere, so the next couple fill-ups may not tell much, but so far, EVERYTHING is better than it was. Road noise is reduced, acceleration in increased, tire mass is down, MPG is up (20% or more), the wife is happy, and I like the look of the new rims/tires on my car a lot better. If you are running 17's, just know, you could be paying an awful price for it!

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Source: Ecomodder.com

LCA Bushings vs Stabilizer Bushings

Its been about 10 months since I got my current ride. When it arrived, it has cracked lower control arm bushes and worn stabilizer bushes. The bad LCA bush can be seen visually but the bad stabilizer bushings can't.

I concluded this from the worn right hand tyres when I first inspected the tyres. My previous ride also had the same issue. You can read my "gluk" battle post for that story.

So when I got this X, the first thing I did was to immediately replace the stabilizer bushings.

After 15,000km and 3 wheel services later, I do not see any uneven wear on the tyres.

Is it safe to conclude that it is possible that you ignore the LCA bushings until a much later time?
If you are cash strapped, maybe. But if money and time are not an issue, please get those bushes changed out.

Change the bush at a workshop outside. If you do it back at Nissan, the will make you change the whole lower control arm. Thats going to cost a bomb ^_^

Downsizing Rims to Improve Fuel Economy ?

Here something I ran into. Maybe we need to consider a downsize at a time when our fuel prices continues to go up.

Car and Driver, a motoring magazine in the US conducted a test to figure out how much of a hit would fuel consumption take if the size of a car’s rims were increased or decreased. To make sure the rim size was the only variable, the tyre make was kept the same, tyre pressure was kept as recommended and tyre compounds were nearly identical. All tests were conducted using a standard Volkswagen Golf and all but the 15 inch rims, were aftermarket alloys.
The results of this test was as expected:
Rim Size (inches)/Overall weight (rim + tyre)/Fuel Consumption
19/24.5kg/(9km/L)
18/23kg/(9.3km/L)
17/22kg/(9.7km/L)
16/21kg/(9.74km/L)
15/18kg/(9.9km/L)

Read the full report on CarandDriver

If you have tried this, I would like to know your experience.