Does anyone have any experience with using Amsoil in their differential or transmission in their LS? I've used Amsoil as much as possible in the past, in the differentials and transfer case and transmission and always loved it and thinking about putting it into the LS is well. Anyone?

 

I think it would be wise to follow the Lexus manual regarding all issue on the LS. They designed, tested, and manufactured the car. Lexus is the expert on the LS as far as I am concerned.

 

do you actually not doing anything unless it's in the manual and only what the manual states?

 

Easy there, cowboy! Let's play nice!

 

How is that not nice? It's just an honest question to a response (that really added nothing to the thread).

 

I would use amsoil in the rear diff without question. However for the transmission id leave the fluid alone unless you are having problems or if you have to do it id use Lexus oem tranny fluid.

 

A oil analysis is needed if yur gonna pit one synthetic oil against another : or Dino oil for that matter syn versus syn, dino,,, dino. do ya ever really know if it runs better or is that much more efficient or long lasting otherwise?

 

As long as it's the same grad yes you can. Some manufacturers have a better product than others. Lexus dos not manufacture lubricants and the suplayer changes from country to country and withe time.
"Differential oil: Differential synthetic gear oil GL−5 75W−90 or equivalent
1.35 +/-0.05 liters."

 

I've searched and cannot find it online, but there was a Toyota Motor dissertation discussing why they did not at the time fill with synthetic at the factory. The long story short was they saw no benefit through 500k miles, if the recommended interval were followed with dino juice. None of us are setup to research this subject, it is cost prohibitive. Going back to the Mobil 1 ads where taxicabs ran 24/7 and racked up x,xxx,xxx number of miles, we know that reasoning was flawed, those are ideal conditions. Less than ideal would be cars that sit, never warm up, go short distances, etc.

I personally use synthetic in all 4 of our cars, 3 of which were not filled from the factory with it. The reason is it seems there are always $25 5qt. jugs, with $10-$12 rebates, so I'm ok with the price. I also feel better when it's < 20F and I know I have synthetic. But this is all predicated upon the price above. My cousin uses oil that's $10.95/qt. online, discount, and that's just too rich for my blood. my .02 I'm ok with the Pennzoil Platinum and Mobil 1 types with rebates...

 

Walmart carries oils like Mobil 1, Pennzoil, Castrol, etc... These are all less expensive then Amsoil and will perform just as good or better.

 

Sometimes folks can be very particular, or there could be engineeering.....a BMW 320i has different oil than a 328i and 340i, etc. M cars have another oil. Mobil 1 Euro is no longer approved for BMW. Other folks say oil is oil. In theory, one shouldn't cause any harm by using better oil, but obviously Toyota engineers don't believe in the need for synth, at least 10 yrs. ago. And I remember that 500k figure, that they were confident dino juice, changed per the intervals, takes the motor through 500,000k, with no detrimental effects. I believe them. But prefer to use synth.

 

I'm sure AmSoil is great oil, but you're paying a HUGE premium for the way it is sold and distributed, sort of like Amway or Cutco Knives. It's a Multi Level Marketing (MLM) company.

I just buy Mobil 1 at places like WalMart or Costco and save the money for other service or repairs. It's a proven oil and it comes from the factory and is the recommended oil in some of the most exotic, high performance cars.

Your car is not going to last any longer on Amsoil.

 

I have an LS430 with the 5 speed. I tried Amsoil and Redline D4 in the transmission and I didn't like either of them - it felt like they 'slipped' too much (more so in the planetary gearset than the torque converter, it seemed weirdest while shifting down from fifth) , I don't know that either would jeopardize the transmission's longevity but my personal experience tells me that Toyota / Aisin designed the transmission to work one way and ultra-premium synthetics aren't beneficial to operation.

I ran redline in the differential for awhile and I have no complaints, but I couldn't tell any difference between my factory fluid with 70k miles and my fresh redline heavy shockproof.

 

There are plenty of very good scientific analysis available on various oils. I recommend them highly, they dispel opinions divorced from evidence. I drive 5-10K miles per year, therefore, the cost is negligible. At the end of the day, some oils truly are better than others, at different temps and applications. I appreciate the feedback based on experience and evidence that some have given. Thanks guys.

 

Right, and those are readily accessible. Thanks.