Not significantly enough by themselves to notice a difference. Spend the same $1500 on a Civic VX or CRX HF and hypermile that thing instead of dailying the BRZ if you really want great mileage ;)

I'm probably going to put Michelin Primacy A/S on them for year round use, and comfort which I've put on other cars and enjoyed.

You'd yield a higher weight loss by getting a AAA membership and removing the spare and tools in the trunk. That's almost 30 lbs off the rear:
http://www.ft86club.com/forums/showthread.php?t=7881

As well as owners manual and trunk liner :lol: you'd lose almost 36 lbs total.

Dropped off 6 lbs per corner from new wheels and tires. Didn't notice MPG going up at all.

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As previously stated, width and tire compound have more to do with fuel economy than anything. Also how inflated the tire is. Your weight will have some effect but it is much smaller and is usually offset and then some by the much larger effects of width or tire compound.

No measurable difference but you will have an automatic 2-3mpg loss if you dont keep the stock tires lol.

Not about mpg, but interesting youtube video:

[ame="https://www.youtube.com/watch?v=AgMXNvu0eWI&t=240s"]https://www.youtube.com/watch?v=AgMXNvu0eWI&t=240s[/ame]

Yea the editor of WR magazine and the one that does the binaural audio videos is really cool and into STX. Knows his stuff about making a decent handling car and is well versed and drives alot of cars every year.

I'd stick to a 215-45- 17 tire /wheel. The Michelins that come stock are solid for MPG. Find a nice forged 17" wheel (not too wide , I'm talking 17x7 or 17x7.5). Volk CE-28 comes to mind, they are about 13 lbs per wheel, 10-spoke design.

**Also no one had mentioned yet, but get some BRZ under panels for the aero gain, that will improve MPG... by how much, I'm not sure exactly.

I'm getting about ~29mpg with about 50/50 hwy/city driving. Stock wheels, tires were never stock, as I purchased the car with about 35K miles on it. Tires are currently some econo Nittos in stock size. Am thinking of 17x8 RFP1s with 215/40x17 Premier A/S or Conti DWS to just leave on year round. Just daily driving with ability to put big brakes on if I feel the urge in a year or two.