mitsuguy

iTrader: (2)

well, you keep following lexus recommendation, and I'll follow what the rest of the industry recommends, which are shorter oil change intervals, and better oil selections, and I'll never worry about engine oil sludge...

is lexus wrong for maybe not requiring as much maintenance, maybe, would more frequent oil changes kept some of these engines from gumming up, sure, would it have solved all of them - maybe not, but either way, I'll keep with my standard practices, and you can keep driving cars with oil sludge issues...

TunedRX300

It is perfectly fine to do above and beyond what Lexus calls for. But make no mistake, what is written in Lexus' official owner's manual is what Lexus legally requires owners to do in order to honor warranty. No one should play a guilt trip, let alone denial of warranty, to owners who change oil at 7.5K when they do not operate in special conditions.
One can argue Lexus' official recommendation is not enough. But as long as Lexus did not issue an offical TSB to change what is written in the owner's manual, the financial burden and warranty liability are on Lexus as owners have held their end of the sales contract. Again, owners aren't to be blamed here. Toyota designed the engine, issues the official oil change requirement in the owner's manual.
Now I use true synthetic Group IV based oil and change oil at 6K in normal driving condition, but that does not mean every other owner must do the same thing to get covered in warranty.

mitsuguy

iTrader: (2)

good, we agree then