I decided to stick with the 15" size. These are sport Edition 15x6.5, 38 mm offset, going to fit them with Bridgestone RE 960 Pole Positions. I like the look of bigger wheels but don't like the ride or higher tire weights. These weigh 18 lbs and the tires will be 21 lbs. So I am still going to take a 4 lb hit on the combination.
Interesting. Am also looking at 4 wheels with winter tires for the snowy season. How much more weight would you have added, had you chosen to upgrade to 17'?
That seems heavy for a 15" given that some aftermarket 17" weighs under 18 lbs. Kind of defeats your purpose of not liking the higher tire weights when you could find lighter 15".
I have to agree with 32kcolors. My 18" wheels weigh 18.3 lbs and the tires 22 lbs. However, the road noise definitely increased. The handling is better though. So if you want to keep the cushy, plush ride of the 15's, then those are very nice looking wheels. IMO, you can't go wrong with a multi-spoke wheel for the Prius. ;-)
You are correct but partially incorrect. The rotational mass issue is dependent on the moment arm. The radius of the wheel is important especially since most of the weight is in the rim itself. The longer the radius the more energy has to be exerted to overcome inertia to rotate the wheel. So the same weight 15" requires less energy then the 17". Then look at the tires, the weight of the tire (center of gravity) is also further out from the center of the wheel, plus the 17 " low profile tires most guys buy to get the dame OD are heavier than the 15" recommended size. So from the standpoint of the mechanics of the issue there is still quite a difference attrituable to the moment arm effect. Centrifugal forces also must be considered along with the Coriolis component of acceleration and energy consumption.
Sounds like then that with the 17" setup, and the larger mass away from the center, that once I pick up speed my momentum from the rotational mass would be larger than with the 15" setup. Perhaps what I give up in FE for the tire width, I make up for in the rolling momentum, taking less fuel to keep it rolling once at speed???
"Sounds like then that with the 17" setup, and the larger mass away from the center, that once I pick up speed my momentum from the rotational mass would be larger than with the 15" setup. Perhaps what I give up in FE for the tire width, I make up for in the rolling momentum, taking less fuel to keep it rolling once at speed???" Theoretically yes but apparently getting them going costs more energy and does not out weigh the start up energy difference. Most post on here show that the larger diameter wheels take a hit of 1 to 2 MPG.
