tallman316

I read another forum about some guy running his lex w/ RP 20w 30 and it runs great. I'm wondering will this be a good weight for my '93 LS400. Or could I run 10w 30? If someone is using RP in their LS400 please let me know how it runs and what grade.

steveski

Welcome to CL - You will probably get many responses on this question. While I have never used RP, I understand it is a high quality alternative that is popular in the racing segment. If I didn't use Mobil1 SYN I would consider it though. Many race shops here endorse it.

Rocan

I've heard really good things about royal purple, but haven't tried it myself. I would give it a shot and see how it goes. What are you running now?

haulin79

Here is the best oil forum: http://www.bobistheoilguy.com/forums/ubbthreads.php

tallman316

i honestly don't know, i just got the car a week ago and looking for the right stuff.

PureDrifter

iTrader: (10)

RP is GREAT stuff but most likely overkill for a 1st gen.

if you want to use it tho go ahead, just make sure to use the factory recco'd weight.

damon

Probably is overkill for a 1st gen. but since I was able to find a good deal & I change it myself I use 20/50 RP.

Neofate

iTrader: (1)

Put in 5w 30 if your going to use it. , 10w 30 wouldn't hurt anything, but might as well stick with recommended weight.

omarg

synthetic, in general is overkill. but that's the way i like it. Cold starts are soo much smoother.

Bill Dowd

running 20-50 is a little heavy lexus recommeneds 5w-30 due to the engine design which calls for a thinner oil and running the 5w-30 might help improve the gas mileage.

Khiladi

iTrader: (1)

Royal Purple is good quality synthetic oil, as I use it my NSX. But it is way overkill (and therefore way expensive) to use in our 90 LS. If your LS has been using synthetic oil up to this point and you want to switch brands, sure why not. But if you haven't and are going to be changing the oil within 5K mile intervals anyway, then you really don't need to. These motors have been well documented to go hundreds of thousands of miles on factory recommended oil, so.....

sonyman

Royal Purple is overpriced and underperforming. If you're going to spend that much money in an attempt to get a quality oil run Amsoil or Red Line. Furthermore, running 20W30 would be downright stupid. Even a 0W30 oil is thicker than desired at startup. 20W30 would surely accelerate wear at the upper part of the motor, in the valvetrain.