When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Noob question but I got new synthetic 5w-30 oil sitting in my garage for 7 months now, I was going to use it on my first gen RX300 until it was totaled. My 3rd gen RX350 calls for 5w-20 oil, will it be fine to use 5w-30 oil for the rest of the car's life? I know 5w-20 was for emissions requirements, but is using 5w-30 oil better?
No. You need to use the proper oil.
Your car has variable valve timing and you can't use heavier oil.
My car's manual says that if you are in a pinch you can use the 5W-30 oil, but change it to 0W-20 at the next oil change, so Lexus does not recommend it.
Depending upon where you purchased your current oil, you may be able to exchange it for the proper oil. I have done this at least a couple of times at Pep Boys after I had sold a vehicle and no longer had a need for the unopened bottles of oil I had stocked for that vehicle. I did not even have to show a purchase receipt - I just brought the unopened bottles back to the store. You may have to pay a difference in price but that is certainly fair and understandable. Contact your oil source, explain the situation, and ask if they will work with you.
Noob question but I got new synthetic 5w-30 oil sitting in my garage for 7 months now, I was going to use it on my first gen RX300 until it was totaled. My 3rd gen RX350 calls for 5w-20 oil, will it be fine to use 5w-30 oil for the rest of the car's life? I know 5w-20 was for emissions requirements, but is using 5w-30 oil better?
5w30 vs 5w20 -> Which is better oil? Does not compute.
Assuming both are good quality oils, you will not kill or harm your engine using either. 5w30 gives you a more hotter climate range protection with added modifiers. Personally I prefer least modifiers and would opt for 5w20. If I were you, and were unable to exchange, I would use it with no concerns, specially if you live in the valley or southern part of CA.
Getting on the soap box warning:
Folks tend to think that sice 30 wt is thicker oil than 20wt so it will not flow. If you trust the range 5-20 and 5-30 you are being told that the flow rate of the oil (a measure of lubrication) covers the span.
That is is why I said that the oil needs to eb a good quality oil, where you can trust the manufacturer when they state 5w-30 it is super set of 5-20 [my caveat of additives applies].
That is is why I said that the oil needs to eb a good quality oil, where you can trust the manufacturer when they state 5w-30 it is super set of 5-20 [my caveat of additives applies].
Salim
I wanted to mention that here in the US we can use the American Petroleum Institute, or API label to make sure the oil is good.
I buy only API rated SN Plus oil,
Also, my car uses 0W-20, does yours really use 5W-20? or was that a typo.
the 1MZFE and the 2GRFE have different build tolerances. If you have no other vehicles to use the leftover 5w30, i would only opt to use the 5w30 to top off between your normal 0w20 oil change intervals in your 3rd gen.
Chart borrowed from another post on this forum for reference.
Someone got paid a lot of money to design and make this extremely mass produced 3.5 v6, I would think the engineer knew what oil to put in it.
In basic terms -- 5-30 will supposedly run thicker at hot operating temperatures. As someone said above flow rates can vary especially in such close weight oils depending on brands and detergents. On some older engines such as a high mileage SBC with higher internal clearances ( could probably run gear oil in those things and be fine) you could put a little thicker oil in it as they age or to prevent oil burn and to compensate for wear.
I would just stick with whats recommend. You may cause more damage by running thicker oil making it harder to reach the valve train / top end of motor. One oil change wont destroy anything Im sure. Youl be fine
No. You need to use the proper oil.
Your car has variable valve timing and you can't use heavier oil.
My car's manual says that if you are in a pinch you can use the 5W-30 oil, but change it to 0W-20 at the next oil change, so Lexus does not recommend it.
Here's answer to your question OP.
What it CLEARLY says - it is OK to do on an on and off basis, but not regularly. Nowhere does it say "do not use" or "not recommended".
5w-30 is fine. the engine when it first came out used 5w-30. i'm using 5w-30 currently. if still not sure, go ask the guys at bobistheoilguy.com. its not that much thicker at all. in california it's fine.
To me 5Wxx and 5Wyy are the same oil at the bottom end( where i think it is most important ie. initial startup).At the top end 30W is thicker than 20W. I don't know how thicker would not be better at higher temps and (presumably) higher rpms. I'd like to know the top end flow rates if anyone can provide. Obviously it needs to flow properly at higher temps.
To me 5Wxx and 5Wyy are the same oil at the bottom end( where i think it is most important ie. initial startup).At the top end 30W is thicker than 20W. I don't know how thicker would not be better at higher temps and (presumably) higher rpms. I'd like to know the top end flow rates if anyone can provide. Obviously it needs to flow properly at higher temps.
Since you asked ..
Single weight higher number oil has lower flow rate, but as the temperature goes up, it flows more.
People get confused by multiweight numbering and keep thinking of them as fixed weight (number classification). The additives alters the flow rate and provide consistent flow rates over wider temperature range.
At the end it is the "flow rate" over temperature range and not thick/thin. Thick or thin is measured by "viscosity" and not the W(weight).
There are lot of other properties of oil that make it a quality oil ,,, detergent, forming a film on metal surface.
04-18-19, 06:19 PM
Can I use 5w-30 on my RX350?
