is it a good idea to use 20w-50 on a lexus sc400 1uz-fe?
it currently has 110,xxx.
or what do guys recommend?

 

There is zero reason to use that thick of an oil... I have seen the 1UZ engine with over 500k miles on it, still using 5w30.

 

I wouldn't suggest running that thick of an oil. I would run what the cap recommends. 20w-50 may cause higher oil pressure. Since you are in Nevada call your local dealer and ask what they would recommend for the heat out there.

 

If you live in Las Vegas, 10W-40 is the thickest I would go. If you live in Reno, 5W-30 or 10W-30 will be fine (definately use 5W-30 in the winter cause it can get mighty cold in Reno).

20W-50 wouldn't hurt anything but your pocketbook (you'd get at least 1 MPG less due to the drag on the engine it would cause).

 

Just use 10w-30. You will be fine. 20w-50 are those engine's with 200k+ with aLOT of blow by.

 

you can actually kill your motor with 20w-50. these motors have tolerances so small that anything over 40w can potentially damage the engine.

 

i use 10w-40 and i have over 300k on my 1uz

idk about 20w way too thick

 

Take some time to read the oil forums on Bob Is the Oil Guy and you will learn more than you ever wanted to know about oil & filters. There are some really smart people on that site who are willing to share their unique knowledge about the subject.

To answer your question: I would NEVER for even the slightest moment consider running 20W-50 in that engine. If the cap says 5W-30 then you can run that until the thing dies. If you're in a really hot climate, then a 10W-30 would be fine (it is the same "thickness" as a 5W-30 at normal operating temperatures). And if you are REALLY worried about the heat, then go with a synthetic or a blend, although it's probably not really necessary. If the higher mileage is a concern, then choose a high mileage oil (they supposedly have extra seal conditioners in them that help keep the seals from leaking).

None of the above will fix pre-existing leaks. Period.

For what it's worth, I live in Texas and I run full synthetic 5W-30 and high quality oil filters (Bosch Distance Plus, Purolator PureOne, Mobil1, etc.) in both of my LS430s...but that's just because I'm ultra **** about oil and filters and the extra cost doesn't both me with these cars because I plan to push both of them beyond 200,000 miles.

In my 2000 Avalon with 130k on the odometer, I used a dino high mileage oil and PureOne filters. The thing still ran like a sewing machine when I sold it a few weeks ago.

 

haha what a joke this statement is