Kyle j

 

Do you need to keep it legal? ie: speedo accuracy. If so, rolling diameter of the tyre has to be within 15mm of factory (in NSW)

If 215/45/17 is the correct factory tyre (diameter 625mm) , and you want to go 245 18s, you'll want 245/35/18 (629mm).

A 245/45/18 is 678mm which will put your speedo out by about 8%. So cruising at 100kph on the speedo might be an actual 108 (depending on how far out the speedo is from factory, they often ready 2% fast).

Probably should keep it legal as we know what its like in NSW. ill go for 245/35/18 then. thanks.

Now to decide if to do coilovers or lowered springs and shocks 

245/40/18 would be a better option or even 245/35 but that's not a very common size. Either way your guards will need to be rolled

Thank you. Now to convince my brother to roll the guards for me. will i need to do front as well

Need advise. Got a 04 gen 4 Liberty looking at putting larger and wider rims and tyres. Currently have 215/45/17 if i want to go to 245/45/18s or similar will i need to roll the guards