Question re my 2013 RX350. Could shifting gears with standard option cause damage to transmission vs using automatic option?

 

Unlikely, but why do you want to do that. No advantage most of the time.

 

The only advantage would be in downshifting to save brakes.

 

That is an old BS wives tale. You risk damaging a $5000 transmission to slow down wear on $50 brake pads. Just drive it in automatic.
The 6 speed is a great, fast shifting, responsive transmission and in auto mode will downshift as needed to help you slow down and be ready to accelerate again.

 

Not BS. It *does* help you slow down without braking. The issue, however, is given what you said whether it's worth it.

 

The BS was the cost benefit of transmission wear vs brake wear. This started back when all cars had manual transmissions and some folks downshifted to stop and others just hit the brakes then pushed in the clutch.
I wonder if there are any studies to indicate your brakes actually last longer with the downshifting.
However back in those days almost all cars had drum brakes front and rear (or in the rear only starting in the 60s) which were terrible at stopping you quickly compared to modern disc brakes on 4 wheels. So Downshifting probably helped you stop shorter safely with only some wear on the clutch and maybe synchronizers if your car had them. Automatic transmissions back then did not really have a manual option. Most just had Park, Reverse, Drive and Low on a column shifter and 2 or 3 gears

 

Back in the day, you downshift with a manual transmission by revving the engine to match expected speed on the downshift to minimize wear on the clutch, and the lower gear then help slow down the car a little bit. When it's time to finally change clutch out you change the throw out bearing and the clutch plate and disc. With an automatic trans, you can't rev the engine to match the speed so the clutch pack absorbs the shift energy when down shifting. Changing a clutch pack in an automatic transmission is definitely not as cheap as changing a clutch in a manual, or brakes. It's your money though, and as a commercial says, "use it how you want to".

 

Ah the good old days. Now some cars have automatic rev matching in manual transmissions
​​​​​​https://openroadautogroup.com/blog/w...ransmission-do

 

Mind blown....