GXKing

Boy, they sure have you guys brainwashed into believing that you MUST use 20 weight oils, dont they! Whether anyone believes it or not, it is mostly just for CAFE! Want proof? Visit an australian oil site such as Castrol Australia, Valvoline Australia, or Nulon. Use the lube guide, and you will see that the exact same engines that are used in Toyotas, Fords, Lexus and Honda that specify 20 weight oils in the US, recommend 30 and 40 weight oils in Australia. The EXACT same engines! If you look in your Lexus manual, you will also notice that it says RECOMMENDED viscotiy..... It doesnt say required. So if you wanna believe the CAFE hype, go ahead. 10w-30 in my GX 460 because thats whats on sale! Suits my climate and pocket just fine!

JimH2

Do you believe that the 30 weight oil is superior to 20 weight in protecting the engine in your climate (e.g., hot summers and/or highway speeds) ? Would you even consider using 20 weight oil if it were more readily available and cheaper to purchase ? I have made the assumption that the 20 weight oil can provide adequate lubrication.

GXKing

Of course I believe it! Its actually in my manual. The manual states: "SAE 0W-20 is the best choice for good fuel economy and good starting in cold weather. If SAE 0W-20 is not available, SAE 5W-20 may be used."
On the next page it goes on to explain what the numbers mean: "The 0W portion of the rating indicates the characteristic of the oil which allows cold startability. Oils with a lower value before the W allow for easier starting of the engine in cold weather."
"The 20 in 0W-20 indicates the oil viscosity when the oil is at its operating temperature. An oil with a higher viscosity may be better suited if the vehicle is operated at high speeds, or under extreme load conditions."
Lexus clearly implies that there is some advantage under certain conditions with the use of a higher viscosity oil.
I would consider using a 20 weight oil if it was more economically priced and it suited my driving conditions.

sweetboy02

Hahaha, i may need to learn the oil viscosity in order to be part of the thread. However, even I'm master about the oil viscosity, i still use whatever the Lexus recommended. They are making cars so they know what the best used for the car. I definitely won't mess around with that. Good luck guys

usmcxm35

I just finished my oil change on my RX. The manual calls for 6 quarts of 0W-20, so I went to Autozone picked up the first 7 quarts of 0W-20 and ran out the store, then went to Toyota and picked up the filter. As I was bottling the USED oil, I then realized that I had filled the RX with 1 quart of 0W-20 and 5 quarts of 0W-30. What do I do now, the recommended oil change interval is now 10,000miles in the manual, but I change it every 5. Do I walk to Autozone and buy 6 more quarts or just wait until the next 5,000 miles rolls around? I live in NYC, so this next 5,000 miles will be in summer temperature. Any ideas?

MEP7557

Since you are doing 5K oil changes I think the 0-30W will be fine until the next change.

usmcxm35

And what about the 0W-20 / 0W30 Mix...?

MEP7557

I would not worry about that either. They will mix together. If it bothers you, you should change it.

JimH2

Even though it does not work this way, think of it as having 0W-29 in the crankcase now? I would leave as is and change at 5,000 miles, since you are using the same brand (and basic specs) of oil.

Hayk

iTrader: (1)

I think you should be okay, as others stated. Lexus used to recommend 5W30, so that's not far from what you have now.

Jerome

Going to advise against keeping the mixture of 0W-20 and 0W-30. I would dump the mixed oil and use the correct synthetic 0W-20. We all assumed that Toyota/Lexus did no changes to the internals of the engine to accommodate 0W-20 oil. I'm no expert but from all the auto tech readings I've done, most manufacturers, like Ford/Honda design pistons/connecting rod, etc. to be lighter for use with 0W-20 oil. The end results are less internal friction, better efficiency...which translates to better MPG. Case in point, I know a relative who experienced engine problem when he used 10W-30 in his 2008 MDX for 3-years; most Honda switched to 0W-20 since 2003. There's no conclusive evidence that the 10W-30 oil cause one of his piston to fail but it's highly suspect.

JimH2

I believe the recommended oil by Acura for that year and model was 5W-20.
When you say it is highly suspect, are you saying the Acura Service Dept. has suggested that was the likely reason for failure. As it would be under warranty, it would be interesting to know if the problem was fixed free under warranty based on the person using the 10W-30 oil.

Jerome

Acura service dept fixed under warranty w/o any concern for the oil. Yes, Honda switched 5W-20, but in the manual 0W-20 or 5W-20 is recommended.

katman

I picked up 1 quart 0-20 at the dealer's outrageous price shortly after I purchased my 450h. After looking at the specs I went to the local Wall Mart and they have 0-20 for less than half the price. So, that's where to go to save some money on the oil.

I have no problem using 0-20 if that is what the manufacturer recommends for my location. For several years VW dealers were the only source for oil that had the correct spec for the TDI engines. Those who had engine problems and weren't using the recommended oil had a difficult time getting warranty repairs.

tsslaporte

^ All you need is oil that meets the right specs which is listed in the owners manual, and you can diy and use w/e oil you want. Just have receipts ready if a warranty claim is needed.