Anyone using 5w-30 yet?
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From: CT
Last edited by Lingus; Aug 17, 2025 at 09:30 AM.
Racer
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If it specd by Lexus in one global manual, end of discussion it works and tested.
Just make sure you select the ambient range correctly (ie 0w30 below freezing and above freezing anythingW30).
Side note:
Clearance and tolerances are soo loosely used these days on oil threads, i dont think folks know the difference. So heres the deal. Clearances are the spaces between parts, tolerances are the allowed amount of variation from the spec'd clearance. Mass produced automotive engines generally all have pretty similar clearances, regardless of grade spec'd. Where things change is when we get down to thinner oil grades like 0W-12 and 0W-8 where the MOFT just isn't there with these ultra thin oils, so the solution is to increase the bearing width, to increase its load carrying capacity and provide a larger film over which the load is spread. This increases friction of course, but apparently the increase in friction here is less than the overall savings by going with the thinner oil when looked at as a whole. This was heavily experimented with in Japan long before it made its way to North America.
Just make sure you select the ambient range correctly (ie 0w30 below freezing and above freezing anythingW30).
Side note:
Clearance and tolerances are soo loosely used these days on oil threads, i dont think folks know the difference. So heres the deal. Clearances are the spaces between parts, tolerances are the allowed amount of variation from the spec'd clearance. Mass produced automotive engines generally all have pretty similar clearances, regardless of grade spec'd. Where things change is when we get down to thinner oil grades like 0W-12 and 0W-8 where the MOFT just isn't there with these ultra thin oils, so the solution is to increase the bearing width, to increase its load carrying capacity and provide a larger film over which the load is spread. This increases friction of course, but apparently the increase in friction here is less than the overall savings by going with the thinner oil when looked at as a whole. This was heavily experimented with in Japan long before it made its way to North America.
Last edited by Framestead; Aug 17, 2025 at 01:31 PM.
Thread Starter
Pit Crew
Joined: Aug 2021
Posts: 163
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From: CT
if it specd by lexus in one global manual, end of discussion it works and tested.
Just make sure you select the ambient range correctly (ie 0w30 below freezing and above freezing anythingw30).
Side note:
Clearance and tolerances are soo loosely used these days on oil threads, i dont think folks know the difference. So heres the deal. Clearances are the spaces between parts, tolerances are the allowed amount of variation from the spec'd clearance. Mass produced automotive engines generally all have pretty similar clearances, regardless of grade spec'd. Where things change is when we get down to thinner oil grades like 0w-12 and 0w-8 where the moft just isn't there with these ultra thin oils, so the solution is to increase the bearing width, to increase its load carrying capacity and provide a larger film over which the load is spread. This increases friction of course, but apparently the increase in friction here is less than the overall savings by going with the thinner oil when looked at as a whole. This was heavily experimented with in japan long before it made its way to north america.
Just make sure you select the ambient range correctly (ie 0w30 below freezing and above freezing anythingw30).
Side note:
Clearance and tolerances are soo loosely used these days on oil threads, i dont think folks know the difference. So heres the deal. Clearances are the spaces between parts, tolerances are the allowed amount of variation from the spec'd clearance. Mass produced automotive engines generally all have pretty similar clearances, regardless of grade spec'd. Where things change is when we get down to thinner oil grades like 0w-12 and 0w-8 where the moft just isn't there with these ultra thin oils, so the solution is to increase the bearing width, to increase its load carrying capacity and provide a larger film over which the load is spread. This increases friction of course, but apparently the increase in friction here is less than the overall savings by going with the thinner oil when looked at as a whole. This was heavily experimented with in japan long before it made its way to north america.
Racer
Joined: Jan 2025
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I'm indifferent to what anybody does with their vehicle. However, in the case of the LS 500 how does different oil viscosity recommendations square for the same exact vehicle? Right now GM has had to recall tens of thousands of Silverados tahoes and suburbans because of 0w-20 oil. What is the factory fix? 0w-40. Given all the tundras grenading over the last 3 years, I definitely would not run 0w20 on that motor. Period. Same motor, different tuning. In my opinion, 20 weight does not stand up to high temp high load conditions, period.
I know this is muddying the proverbial waters.
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Pit Crew
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From: CT
Yes I inferred that in the post. Irrespective of what is causing these engines to implode, What is true in the case of GM's failure is that 0w-20 does not offer the protection required for hi load high temperature operation. What is causing toys V6 TT failure is still unknown although they are blaming it on swarf.
