225/50/17 Lexus IS300h

[jackdublin]

Has anyone tried 225/50/17 on Lexus IS300h previously? I note that the guidance says 45 is recommended, so not sure how extra 11mm will impact the ride.

On 18 inch currently and want to go back to 17 inch to have more comfortable ride. Found pretty much brand new alloys but they are coming off from 2008 GS300. 

[Boeryeoes]

The 50 height is not to spec. 45 is and the ride is plenty comfortable on sporty tires (Goodyear Eagle F1 A6).

I imagine 50 will not be much different but i would go with a tire with firmer sidewalls (ie. sporty tires).

[Mr_Groundhog]

Makse sure you can pass your MOT with those or you may end up paying up big money every year....

[jackdublin]

I wonder if it may impact safety too. 

[Mr Vlad]

300h. SE grade models feature 16-inch alloy wheels and use 205/55R16 91W-sized tyres. Executive Edition, Luxury and Advance models ride on 17-inch alloys and use 225/45R17 tyres. F Sport and Premier grades use 225/40R18 88Y tyres up front and 255/35R18 90Y at the rear.20 May 2015

I've copied and pasted this. I'd forgotten the F sport had a wider tyre.

There's no harm going down to 17' But you'll have to have all four tyres the same size and they'll have to be aspect ratio 45 so that the speedo isn't compromised on accuracy.