My single owner 2017 RX350 is AWD with about 30,000 miles. The car is constantly garaged and never driven under harsh operating conditions. I have seen on the Forum numerous DIY posts on changing these fluids, but I no longer work beneath the car and would bring it to Lexus for these fluid changes.

The question is whether I really need to change these oils. Looking at the Lexus Scheduled Maintenace Log, starting at 15,000 miles and then every 15,000 after that, the recommendation is to replace the fluids. But ONLY if operating under their listed (severe) operating conditions, and NEVER under regular driving.

I really want to be kind to my car, but not obsessive about it. So, I question how important it is to replace both fluids. Interested in everyone's thoughts.

 

All fluids need to be changed eventually because they degrade over time and they break down. In your case it might be once every 10 years or more. It is so easy to do. I went and bought the recommended gear oil and took it to my mechanic when the engine oil change was due. While up on the rack he took care of everything. Not a major operation and very inexpensive. I do my RX every 5 years whether it needs it or not.

 

Make sure you change out tranny and coolant fluid like clock work, those are the important ones. Diff and transfer case are not really too important but, its cheap, really cheap, like 80 per diff and 120-140 last time i changed the transfer case, so might as well change them regularly. I highway drive a lot so I replace diff/transfer case later than most, every 40-50k, and coolant every 60k-75k since it turns acidic, along with tranny fluid.

My first tranny change was around 90k miles and you can definitely tell I waited too long. Occasionally id say one out of 5 city drives ill let off the gas and then go right back on the gas and it'll be a rough engagement. Kind of like when the tranny is cold but happens when its warm for me. I am about at 150k miles so its somewhat expected, it shifts and drives fine 99% of the time still.

 

Agree with jcg0324.

I would just add that changing the first time is probably most important just to see the condition of the magnetic drain plugs. You want to be sure that there are only fine metal shavings and no serious wear.
I did mine at 30,000 miles. Very cheap and very easy job. Everything looked good, so I know that I can go longer if I wanted.

A shop should not charge much for the labor (use RedLine as a less expensive alternative to the Toyota gear oil which is crazy expensive), since these jobs are very easy and quick drain and fill.

 

Thanks all for your comments. I mentioned that I no longer do work under the car (used Redline and Royal Purple oils then). Started bringing the car to Toyota for oil changes and it took a while to accept that they weren't using what I considered to be premium oils. Anyway, I mentioned bringing the car to Lexus for diff and transfer oil replacement since I only wanted to make sure they use the approved oils. Happy to bring the car to Toyota instead. I wonder if I can assume that Toyota uses the exact same weight/type of oils in the Highlander?

 

Why not just buy the amount and brand of oils that you need and bring it to the Toyota dealer?

 

tbh for the rx you dont need the premium oils. redline, mobile 1, amsoil are probably the best on the market but the application for the rx isnt too important. the dealership oil will hold up just fine. Now if your talking about a performance vehicle that tracks or is driven hard it might be worth it, I'm sure toyota will put the correct weight/oil in the fluid change, their computer system tells them what to put through the vin number regardless if its a toyota or a lexus

 

Thanks guys! I'll just let Toyota handle it all. Also need to change the brake fluid.

 

"My first tranny change was around 90k miles and you can definitely tell I waited too long. Occasionally id say one out of 5 city drives I'll let off the gas and then go right back on the gas and it'll be a rough engagement. Kind of like when the tranny is cold but happens when it's warm for me. I am about at 150k miles so it's somewhat expected, it shifts and drives fine 99% of the time still."

my 2016 does the same exact thing, it's super annoying. I did the same 90k trans fluid change and I'm currently atabout 140k miles.

just out of curiosity, does your rx also have the infamous hesitation whilst accelerating from a stop? where it feels like it goes from first to second just fine, but then it does nothing for about 3 seconds then abruptly resumes in 3rd or 4th. Lexus claims it's a software issue, and I was thinking the 2 issues might be related.

 

I did have this issue and how i fixed it was get off eco mode. I just leave it on normal mode and it ever since then i havent had any hesitation when accelerating from a stop. I feel like eco mode doesnt save any gas, turns the ac all the way down, along with poor throttle inputs.

 

For me I like to be on top of my preventative maintenance. I change my ATF, transfer case and differential fluid every 30K.

 

Same scenario and resolution. ECO mode was more a bother than a help. Got better gas mileage in normal mode as well.

 

Would it be best to follow the intervals? Yes
Do most do? Probably not

 

The OP does not specify, in the original post, which fluids he is referring to. Different fluids get different consideration. I tend to follow the recommendations of the Car Care Nut.

 

I specified the exact fluids in the title.