this phenomena is well known among Prius owners, switch to 17" equipment and fuel economy goes out the window,usually to the tune of US 4 MPG. Although this is something I wanted to do, Im still looking at wheels but have been researching more exotic 15" dia wheels in an effort to drop more weight and make the best of it. If light is good, lighter with LRR tyres is even better, right?
We think stock 17" optional factory alloy wheels are 11kg and 15" alloy wheels are 7.4kg. Stock tyres in Au are 195/60 Green X, conservative pressures at 42 psi, unless you are fond of bone jarring in this aluminium chassis.
Handling isnt great in stock configuration, so in an effort to hold cornering speeds I figured being closer to the same speed would actually save me fuel, so I decided I actually needed a wider footprint and a lower car, in doing so I considered lowering the car and just using spacers on the wheels. People say handling is greatly improved lowering the car and fitting heavier sway bars. This is what it would look like [photoshop simulation]. But Im unsure about bearing loads on a FWD etc... by spacing the rims out 20mm rear and 12mm front.
and how it actually looks stock
Just maybe theres something wrong with me but I love this freakin car! Ive done 4.2 litres per 100kms for 1002 Kms on 44 litres using glide technique, ordinarily Prius is rated at 4.9 litres 100 Kms.