0W20 in a 1UZ-FE?

[EyesofThunder]

Friend of mine is a Lexus tech and we have been looking at the specs of the 1UZ-FE and the 1UR-FE/FSE and it looks like Lexus LOOSENED the specs for the 1UR-FE/FSE compared to the 1UZ-FE (89-00 at least).

He has a 98 ES300 and has run 0W20 in his for the past couple years with zero issues and is over 200k miles. He bought the car new.

Thoughts? The only thing tighter on the 1UR-FE/FSE is the rings, but not by much.

5W20 oils weren't available when the 1UZ-FE was designed, and likely Lexus wouldn't have gone back and done the testing needed to prove it out. But I can't see from an engineering standpoint why the 0W20 or 5W20 wouldn't be a good thing. These are awfully tight spec'd engines.

1989-2006 1UZ-FE/3UZ-FE (4.0L and 4.3L V8)

Rod oil clearance: 0.0011" to 0.0021"
Main oil clearance: 0.0016" to 0.0023"
Ring Gap: 0.0118" to 0.013" (87.5mm/3.44" bore, 82.5 mm/3.25" stroke)

2007-up 1UR-FE/FSE

Rod oil clearance: 0.002" to 0.0024"
Main oil clearance: 0.0024-0.0027"
Ring Gap: 0.009" to 0.013" 94mm/3.70" bore, 83mm/3.26" stroke


Edit: Found this chart, looks like Lexus approves 5W20 in the GS300, GS400 and GS430:

 

[4U2QUIK]

synthetic/nonsynthetic makes a big difference on what can be used also.

 

[EyesofThunder]

I have run only synthetic for years, mainly due to the high temp abilities of the synthetic more than anything.

synthetic/nonsynthetic makes a big difference on what can be used also.

And I found this:

 

[EyesofThunder]

Someone said that in outside the US that 0W20/5W20 is NOT recommended in a Lexus, only in the US where the fuel economy is stricter is it the recommended oil.

Anyone here from abroad that might know?

I did put 5W20 in this last oil change, hp is up a little and hard to tell on fuel economy so far, but it looks like it might be up some. My interest is cold start, fast pumping of the oil to the engine

 

[Toytech]

I'm a Toyota/Lexus tech in Canada and most of our newer cars are recommended to use 0W20 oil. The chart you show is the same as ours.

 

[EyesofThunder]

So far with careful driving and 5w20 I am at 277 miles and just hit half tank..... Any chance you can see what European lexii recommend for oil?

I'm a Toyota/Lexus tech in Canada and most of our newer cars are recommended to use 0W20 oil. The chart you show is the same as ours.

 

[Spinnetti]

I've run a variety of synthetics and I'm racing at redline, up to 24hrs straight on a car showing 250k on the clock. 0-30 and 0-40, as well as 5-30 all seem to work fine. I see some oil consumption, but haven't pinned it down to which oil I got it with. Some times it burns some, some times it doesn't. The thinner the oil, the better the heat transfer, and the lower the drag (+power and economy). Assuming sufficient oil pressure and volume, thinner would seem to be better...

 

[stevieg]

I'm the odd-ball and I run she'll rotella-T 15w40 diesel oil year round in Canada without issue. I used to run Mobil1 5w50 and had consumption issues in my race car so I switched to the rotella and all consumption disappeared

 

[cribbj]

On the Ferrari forums, oils are a hotly contested subject. Awhile back a very smart guy, albeit a medical doctor & surgeon, not a mechanical engineer or tribologist wrote this article(s) which has some intriguing points:

Motor Oil Articles by Dr. Ali E. Haas

Then some other really smart guys, again not tribologists, but several of them mechanical engineers, and one very well known, very well off, private racer (the owner/builder/driver of the Pininfarina P4/P5, Jim Glickenhaus) chimed in with some opposing views here:

More on Thin Oils, A Used Oil Analysis

Take it for what you will. I know that we have at least one experienced tribologist on this forum, and I'd sure like to have his opinion on running lighter oils in various engines.

FWIW, I've changed from a Ferrari recommended 5w-40 for my 550 Maranello to Mobil1 0w-40 recently. No real noticeable differences, however I'm looking forward to the results of the first oil analysis.

 

[Spinnetti]

On the Ferrari forums, oils are a hotly contested subject. Awhile back a very smart guy, albeit a medical doctor & surgeon, not a mechanical engineer or tribologist wrote this article(s) which has some intriguing points:

Motor Oil Articles by Dr. Ali E. Haas

Then some other really smart guys, again not tribologists, but several of them mechanical engineers, and one very well known, very well off, private racer (the owner/builder/driver of the Pininfarina P4/P5, Jim Glickenhaus) chimed in with some opposing views here:

More on Thin Oils, A Used Oil Analysis

Take it for what you will. I know that we have at least one experienced tribologist on this forum, and I'd sure like to have his opinion on running lighter oils in various engines.

FWIW, I've changed from a Ferrari recommended 5w-40 for my 550 Maranello to Mobil1 0w-40 recently. No real noticeable differences, however I'm looking forward to the results of the first oil analysis.

Thanks for the links... For everybody, there is no "one size fits all". Most people are talking street cars, but street and competition uses are completely different, and with different goals. Your use case really has to determine which of the many answers is right for you. For any real racer looking to win, you'll sacrifice your machine if you have to in order to win. For us low bux racers, we tend to run a bit more cautious, but in the end oil consumption doesn't mean squat in a race car. As long as there is enough oil to get you through the race, its good enough as you'll change it before the next one anyway. Even running 24hr events, as long as I have enough to get to the next pitstop I'm good. A race car doesn't need detergent oil either, as every bit of the oil that is not oil is not good (i.e. surfacants, detergents etc). On my street car, oil consumption, long life, detergents etc. matter a lot more. So, all that said, what do you care about, then pick the data/products that best meets your mission profile. For me, the lowest drag, with maximum heat transfer while still keeping the moving parts going is my #1 priority. 0-30 Castrol Edge is my weapon of choice at the moment, though I'll run 5-30 or 5-40 if its on sale I'd buy redline pure race oils, but too expensive at the rate I go through the stuff (5 cars, 2 of them race cars)