jdanielca

Have a look at this: https://oilincar.com/lexus/ls/4-2004-2012.php interesting.. btw alot of people here do 10W40 or 5w40.... no one uses 0W20. At the minimum 5W30. I really suggest for those of you who intend to keep the cars a long time to switch to thicker oils..... regardless of what anyone is telling you. Even in the manual it doesnt say what oil to use exactly it just says 0W20 for better fuel efficiency. And also dont u find it strange that older generation cars use 5w30 but 2007 uses thicker... there is something that is not being said or is known.

Anfanger

Well, it is actually a very well known fact that 0W20 is better for fuel economy but not as good protecting the engine as thicker oils. If I am not mistaken, Lexus recommends using thicker oil in hot climates.

In US, you can find LS460 300k+ miles going strong, at least, in terms of engine and using 0W20 as it is what Lexus puts in these cars engines.

jud149

Engine tolerances today are much less then they were years ago. Using thicker oil than what car manufacturers recommend for your year can create lubrication problems as the oil doesn't flow as well. Be careful.

Striker223

0w-20 works fine........until the pump can't flow enough to keep up with looser tolerances and increases heat. When you have a thicker oil it will be far more resistant to shear down and heat but will flow more "slowly" and depending on how the VVT and chain tension system is designed to work with regards to overall oil quantity flowing through it per minute/second you may have issues.

The tolerance argument is a common fallacy I see because you have engines like the S 65 and the S 85 that have very much race engine like tolerances that are running 60 weight oil and simply just don't let you rev until the oil is hot enough that that flow rate is high enough that you won't overload a particular section of oil on the bearings.

Think of it this way if you are flowing a huge amount of the thinner oil through a particular area, the opportunity for said oil to sheer down from heat or pressure is less than comparatively then if you were flowing the same oil less quickly through the area with the same loading. In that same vein if you simply had a heavier oil that is more resistant to sheer down and failure from pressure you can get away with flowing less of it through a given area than you could a lighter oil.

However if you flow a massive quantity of even 0w-20 through a given area to the point where the oil is flowing by in such massive amount and so quickly that does not have a chance to shear or fail you actually have a more effective lubrication system than if you were using even a 60 weight oil does barely moving past the area of stress. Hence why you see cars using 0w-16 or less these days, they have INSANE oil pumps that can flow in a few seconds what a big block engine from the 60s/70s could in a minute or more.

The ideal system simply needs to flow enough of whatever weight oil quickly enough that it will never reach a situation in the engine that leads to failure. Now again thicker oil, more overall oil, cooler oil, and higher flow all increase wear resistance but the solution of a massive amount of thin oil allows very low startup drag, huge amount of "hydraulic fluid" supply to actuators and tensioners, and really only requires a massive flow rate pump to work. Again since we can make those types of pumps these days it's not a big issue but before we simply couldn't flow enough quantity to protect the entire way from pump head to rocker shaft without something experiencing failed oil from friction heat/stress. That's why before engines where oiled top down they discovered in racing circuits that the rods and mains were dying from sustained high rpm, so they reversed the direction of oiling so that the oil is reaching the rods and means first. This was because whatever the oil gets to first is the "freshest" part of the oil before it has already been subjected to other heat and stress, that way if the oil is used up so to speak protecting the rods and mains it doesn't matter as much if the rocker arms are the pushrods were damaged since those don't lead to total failure nearly as quickly.

In the case of the 460/2UR-FSE the reason you have to fill it with a huge amount of oil is that 1/2 of that oil is never actually in the sump when the engine is running, the pump flows a crazy amount of it to the point half or more is busy inside the engine or on the valve train. A 20 weight works because there is simply such high flow through the engine at all times and so much oil it doesn't have a chance to shear down and fail before the oil is "replaced" by a new set from the sump and has a chance to flow down the returns and shed heat into the block/heads and cool off before being sent through again.

However if you increase output.....you increase loading on individual areas proportionately and you now need to flow even faster, cool off the oil even faster, use a more durable oil, or use even more oil overall to prevent failure. You can easily see this in the GSF/ISF/RCF since they are expected to see continuous (hour plus) 5500+ rpm track use with no chance of low load coasting/crisis to allow the oil mass to "catch up" and cool off. They have oil coolers, a more tightly toleranced pump and bearings (less leakage means less work for the pump to flow and more oil is sent per turn of the pump) and a slightly thicker oil to make sure the load on the oil at full tilt never exceeds the ability for the oil to "recover" before being sent through the engine again.

Now if you say....doubled the power you may run into issues. My final example is the extremely strong Chrysler hemi engine design, the "normal" ones use 5w-20 but the high output ones with identical pumps and bearing tolerances use 5w-40 since they didn't want to totally redesign the 6.4 version and risk oil cooler related issues. The 6.2 though does have those changes.

jdanielca

I’m going to have to disagree because this recommend oil thing doesn’t exist

sdls

Think of oil viscosity as blood sugar, and oil pressure as blood pressure.

aristo1987

You can disagree all you want. Everyone is entitled to their own opinions. But the oil recommendation does exist and if you think you're smarter than the people who built this engine. By all means do whatever you want. I can guarantee you 98% of the members on here will disagree with you.

Look at your oil cap and your ls460 manual. It states clearly 0w20 or 5w20. 🤦‍♂️🤦‍♂️🤦‍♂️🤦‍♂️


And who the heck are those peoples? I will rather listen to the people who built this engine.

Striker223

Depends. I doubt heavier oil will flow fast enough in this engine when at the extreme cold side of the spectrum to prevent damage to things far down the chain of oiled parts. It's a crazy long oil path and there are an insane amount of parts and oil jets that need to be fed quickly when started.

Striker223

Oh it does, the older engines didn't have 16 oil jets, four oil operated chain tensioners, 32 oil operated lash adjusters, and much wider heads and shorter skirt pistons among other oil intensive systems. The 2UR has HUGE oil quantity requirements and lighter oils can be moved faster for a given pressure and pump capacity, if you use a heavier oil in an engine like this you get BMW style bearing consumption and "normal wear" every 50k miles.

Anfanger

As you probably noticed, I wrote "... hot climates..."
https://www.clublexus.com/forums/ls-...l#post11027550

Striker223

Yeah, he never mentioned where he was though so it's safe to assume that the 20 will work since it was tested to work globally. I just wouldn't mess with it if it gets below 50 where you live

BlazeViper

Fluid dynamics engineering: club Lexus edition

jud149

Couldn't have said it better myself...

+1

TANORWAY

My Ls600hl has only used 0W20 After 136000 miles and 8 years, Doesn't burn a drop of oil between my 9000 miles oil changes.