To be honest, Unless for some reason they get flagged up in any sort of error code I don’t intend going about changing mine until the 100,000 mark! They were last changed at the 6 year/60,000 mile service by Lexus Edgware Rd when it had 21,000miles on it ( After 6 years!) and I only got 45,000 miles on it now, so gonna be a while Yet!