Nope, the wider rear wheels are lighter because the front wheels have a thicker backpad to clear larger front brake calipers. This is common for aftermarket performance wheels that have to cater to many different brake sizes. The wider wheels just use increased concavity to achieve the same effect since rear calipers are almost always smaller. You have 3 main options:
1) Racing/Autocrossing/Competition: square 19x9.5 setup with 265 or 275 width tires all the way around (big range hit).
2) Primarily street driving/efficiency: square 19x8.5 setup with 235 or 245 width tires all the way around (similar to stock range but lighter and better looking).
3) Compromise between the two: staggered 19x8.5 front (245/40 tires) and 19x9.5 rear (275/35 tires). This is what I have and is the only non-rotatable option.
I went with option 3 because I like the balance of looks, range, and performance for sporty daily driving. This is a near flush looking stance and I see efficiency roughly equal to the stock 20's even with the 40mm wider sticky tires. I can get ~250 Wh/mi around town, ~300 Wh/mi at 65mph, and have a lifetime of 298 Wh/mi after 1600 miles with a decent amount of launches. This is a P3D+ for reference.
