I'd go toyota fluid for the sole reason that i have a hard time believing that this fluid is compatible with BOTH T-IV and WS as there have been incidents where people have used WS in T-14, or vice versa, and experienced issues. When I went to buy the same fluid for a drain and fill on my 2008 , the advance auto guy was the one telling me to just get the OEM fluid instead, and for me it just wasn't worth the risk for a difference of $5, albeit for significantly less fluid.

 

Toyota trans fluid all the way for me too. I know lots of people use the Valvoline fluid, and to each his own, but these transmissions are so complicated it's worth it to me to pay the extra money for the proprietary fluid.

 

Pay extra money where I am located, I would pay around $9.00 for a liter of Valvoline Maxlife ATF whereas Toyota ATF T-IV is $4.& some change at the Toyota dealership.

 

​​​​​​Valvoline is cheaper here by half in Colorado. USA
Than WS

 

OP's RX would call for WS

 

Usually anything is less expensive in the US especially when the currency exchange is .70 Cdn to the US Dollar for purchases...
I suppose I better head over to the Toyota dealer before they come to their senses as the price of the Toyota ATF T-IV would translate to about $3.15 US a Liter.

 

For me it's not an issue of price. I want to use the best option for longevity. My suspicion in that other fluids can be as good if not better and in this case may contain additives that DO help with longer mileage. Again the fact that Toyota considers this as never needing full replacement and that "lifetime" = as long as warranty.... I do not have faith/trust.

 

Pleased to hear you are in the 1% group, (For me it's not an issue of price), the other 99%, myself included would most likely consider the Lexus recommended Toyota ATF T-IV for a Drain & Fill if the cost is less than other products available on the market.
Lexus transmissions appear to be extremely sensitive & complicated to risk other products in my opinion, this coming from a RX330 owner who's tailgate glass exploded for no obvious reason.
Certainly not ready for more bad luck as a failed transmission anytime soon. The best way to avoid bad luck is not to ask for it, whenever possible.
Of course no fluids last forever, the reason why CL members DIY their transmissions with a Drain & Fill periodically.

 

This. Regardless of the war on fluids, the best you can do for your transmission is regular D&F of the fluid and change the filter on occasion.

 

Thats true, if there were more documented cases people using the fluid I'd be more confident in something other than Toyota fluid, just between my limited personal experience and what what parts guy/ techs have told me, I'm vary weary. If you go this route, report back and let us know.
That being said, theres so many Lexus/Toyotas that have been serviced by indies that didn't use OEM fluid, but very few, if any, will report it on here.

 

Do you think this is because of limited success or just refusal to share experiences? I haven't been on Club Lexus as long as I have on Toyota Nation and even over there people rarely go out their way to speak about using other fluids (oil, trans, brake, etc). Unless asked to give suggestions and experiences, I have very rarely seen anyone start a thread sharing their experiences in itself, it's always just share when asked which gives me a hunch to why reports are few and far between.

On the other hand, if fluid does directly or susceptible to cause transmission failure, best believe the world needs to know about it over and over again. I've seen these kinds of threads countless times over the years. Which makes sense, you want people to know a bad product and you really don't go out of your way to promote a good product, you just use it if it good for you.

 

Well no, its because a vast majority of people that own cars aren't on forums.

 

CL is an excellent resource website, their loss....
for the longest time I have registered to various forums, even for a Astro Cargo Van I owned for about 3 months (due to a business decision), saved tons of $$$$ with other members' experiences.
Especially as I usually purchase "as is" vehicles in better than average condition that require DIY repairs & some certified mechanics' repairs to pass safety inspections.
Thanks to forums, in the past 10 years, I actually made a small profit when I sold the vehicles besides getting good use from them.
Appears as I hit the end of the line as the RX330 is a keeper hopefully for some years to come, great members here....
figure I give a fair warning, I do not plan to disappear from this forum anytime soon.

 

Most likely the best reason for me not to endorse Valvoline Maxlife ATF brand ....
check this photo, talk about money is no object at least the shipping is inexpensive.

 

No, definately don't get that. Pretty sure transmission fluid these U151E transmissions use is Dexron IV fluid, not III. That's where the Type IV comes in (Toyota version) type 4.