Tire size

[elkubiche]

My X5 uses 255 55 18 but I want to install Michelin LTX M/s that only come in 245 60 18 . Will this greatly affect the handling and safety?

[powers1]

Originally Posted by elkubiche

My X5 uses 255 55 18 but I want to install Michelin LTX M/s that only come in 245 60 18 . Will this greatly affect the handling and safety?

Not much difference,less than 2%...you will be ok as regards to safety and handling.As a bonus since you will have more tyre wall,your ride should also be more confortable.
On the tech side theres a 14mm difference in rolling diametre between the two,the 245/60 is bigger,so the visual effect of this will be a 7mm increase in ride height and 7mm decrease in the gap between the top of your tyre and the bottom of your wheelarch,making you car seem a little bit lowered.
Note that your speedo will also be off by about 2%..

[motordavid]

The chart I use shows a less than 2% diff...but tire size can vary considerably from
brand to brand, and results are nominal using different tire sizing guides.
GL, mD

Tire size calculator

[Fraser]

The Michelin LTX is a light-truck construction tyre and your X is designed to run on passenger-car construction tyre. Not a good idea imo. I've tried Michelin LTX's on my old Range Rover and while they are as tough as they come and wear extremely well, they completely destroyed the ride, handling and steering precision of the RR. I wouldn't even consider them on my X which is a far more sophisticated and finely engineered vehicle than the old Rangie which, after all, is far more like a truck given it has a separate chassis and live (solid) axles front and rear.

[powers1]

Originally Posted by motordavid

The chart I use shows a less than 2% diff...but tire size can vary considerably from
brand to brand, and results are nominal using different tire sizing guides.
GL, mD

Tire size calculator

Sorry,you are right!I dont use sizing guides,just made a mathematical error using my calculator
Shall edit above post...

[cjett]

Agreed with Fraser... I had these on a Range Rover as well. Very loud, just ok traction wise... but, extremely tough and lasted forever. I kept hoping they would wear out so I could replace them.... ended up selling the truck after 20K+ miles on them and they looked like they'd go another 20K (seriously).

I too wouldn't even consider putting them on my X.