TropikalLS

Hey there, I'm new to this forum and I just recently purchased a 98 LS400 with 89k miles. I'm trying to think of some small easy mods to increase mpg and a little performance.

I also own a 95 Nissan 240SX which after using a K&N filter and 0w-40 oil I average 27mpg on a 5-speed doing city driving. I noticed a big difference when revving the engine on light weight 0w-40 compared to say 10w-30 or 40.

In my "new" LS I get around 20.X city driving. Does anyone else run 0w-40 oil?

sonyman

0W40 is thicker than 10W30 at operating temperature. You make no sense and are experiencing a placebo effect.

Bill Dowd

your best bet is to run 0W-30 or 5W-30 for best gas mileage and you can run it year round in the cold and hot weather.

TropikalLS

sonyman: You're right on the placebo effect, there was a variable that was changed in the 240SX and that was a drop in K&N to a AEM Intake with in those oil changes.

haulin79

My favorite oil is German Castrol 0-30. It's available at Autozone, make sure you look at the back of the bottle and look for the "made in Germany" label.

You can read up on it here: http://www.bobistheoilguy.com/forums...643#Post718643

skperformance

iTrader: (6)

motul all the way

Losiho

You're in Florida which is a hot climate, so I say give it a try.

If people bothered to check their owner's manual before automatically telling everyone that 5W-30 and 10W-30 are the only recommended grades, you'll find that Lexus recommend up to 25W-50 depending on the operating temperatures.

sonyman

If you bothered to think that perhaps Lexus has different recommendations for different regions of the world, you'd realize that in the USA, Lexus only recommends 5W-30 and 10W-30 for the 1UZ-FE in the USA, with 5W-30 being the preferred grade unless temperatures are above 100ºF, in which case 10W-30 is preferred.

Losiho

Thanks Einstein. Just as in another thread in the LS400 forum, I can easily post a scan of my oil receommendation page to prove that 25W-50 is one of the recommended oils by Lexus (although I guess you're still going to try and tell me that the UCF10 and 95 - 97 UCF20 4 speed autos have different gear ratios)

And I suppose the 1UZ FEs in the USA are different to all the others in the rest of the world ?

Would you like to explain to us (seeing as though you're the Lexus guru) why my Lexus dealer uses Castrol Magnatec 5W-40 in all RX330s and RX350s, even though 5W-40 isn't listed in the owner's manual ?

sonyman

I never said that you couldn't run an oil outside the recommendations. What I did say is that you were incorrect in assuming that Lexus recommendations do not differ across the world. 25W50 is an extremely thick viscosity, and not something you'd want to run anywhere except in a desert climate. It is not recommended by Lexus in the USA. The OP mentioned that he felt a big difference running 0W-40 oil and I mentioned how that is actually thicker than 5W-30 or 10W-30 at operating temperature. There is no need for him to run a 40-weight in Florida, and Lexus does not recommend doing so in the USA.

PureDrifter

iTrader: (10)

calm down guys, bickering isnt gunna get you anywhere.