I run 285/65r18 Trail Grapplers with half inch wheel spacers...if you do not realign, the tires will often pinch in and lead to unbalanced wear on your tires. It is in your best intrest to get a realignment with fitting bigger tires on the LR
If using Johnson Rods LR3 Lift Kit - Johnson Rods - Range Rover Sport Lift Kit and 275/65-18's are there any known issues with alignments? I'm thinking of installing a set when we get our LR3. What about ride quality and handling? On our DII with a 2" Terrafirma lift and 265/75-16's the vehicle did drive different. Not quite as stable at highway speeds(75-80 mph).