@JamesIS220 Thank you for the elaborate write-up.
I have read a bit online about the head gasket failures on the IS, it makes me feel its a common issue (or should I say a known issue?)
Sometime ago, I did consider upgrading to an Auto IS 250, but . IMHO when it comes to the car buying decision, I cant think of moving to any other brand apart from Lexus. Totally understand when you mentioned what you like about it 😄
As far as the MPG is concerned, I get around 550-570 miles out of a full tank (if it is motorway runs alone). However, I am getting 470 miles consistently. I think that accounts for appox. 35mpg I believe. The trip computer, however shows 38 mpg consistently and 44 mpg on motorway runs.
It seems Michelins are everyone's favourite. Thanks again for suggesting the Energy Savers, at least now the buying decision narrows down to Energy Savers and Primacys.