Thinking of towing a small trailer this summer, looking around for a stout engine oil for the purpose and wondering what others have decided. Mobil 1 esp x4 0w40 has good specs and some european car approvals;
https://www.mobil.com/en/lubricants/...1-esp-x4-0w-40

 

To my understanding the RX350 is supposed to use 0W-20 engine oil regardless; towing or not.

Therefore, I would just use a good quality 0W-20 engine oil and try not to exceed the towing rating of the engine. Furthermore, I would only tow if I had the towing package with the additional oil cooler.

Using oil that is too thick to flow well through the engine small oil passages could cause more problems like internal wear on the rod bearings and VVTi gears. Basically causing the same issues that you are trying to avoid by using the thicker viscosity oil in the first place.

 

Very true statement 0W-20 for 350 engine.

For some engines, Toyota is backing away from 0W. Stay tuned to see if they will change the spec for 3rd Gen RX350. If any one wants to experiment, they are on their own.

Salim

 

I don't think you need any special oil or viscosity for towing.
I use Motul 5W30 + Liqui Moly CERATEC. In my opinion, the best combination for a car with 100+ mileage.
I also use an engine flush before changing the oil (I change the oil every 5k miles)

The manufacturer uses low-viscosity oils to meet environmental standards (reduced emissions) and improve fuel economy. They don't care how many thousands of miles the engine will last. All they care about is that the engine lasts its warranty period.. Then you have cylinder wear, scratches, and scoring.
For those who use low-viscosity oil (which is, of course, recommended by the manufacturer), when was the last time you had your cylinders inspected with an endoscope? Is the hone in good condition? Are there any scratches, scuffs, or "bald spots" on the cylinder walls?

P.S. Interesting fact: the same car with the same engine, but in DIFFERENT countries, may have different recommended oil viscosity grades. Or do they make different sized oil passages for different countries? LOL
P.S.S Newborn babies are given breast milk. Why don't you drink breast milk when you grow up? Think about it...

 

Using higher viscosity for towing is an excellent idea.

2GR-FE engine was used in other models that had 5w-30 in the manual. It works perfectly fine on 5w-30, especially if you have access to Australian owner manual, you might even see 10w-40

 

I use 5-30 in my 2014 RX and 0-40 Mobil 1 Euro in my 2008 RX that gets driven significantly harder and does "truck duties" sometimes. I even switched the oil cap to the 5-30 one... It has been proven that the 2GRs are all the same internally, bearings / clearances etc are the same, even the Lotus unit is almost identical apart from the camshafts and the 0W40 oil spec. The cam phasers were revised on ~11+ cars to help prevent the infamous "Death rattle" that some older 2GRs develop. My 08 LOVES the 0-40, it has the cold start rattle and on the 0-40 it seems to rattle for less time when I start it up, likely due to more oil pressure. The Mobil 0-40 also does a great job of cleaning up a lot of the sludge left behind from the PO's lazy oil change intervals.

 

I have been using an oil mix of 4.5 quarts 0w20 and 2 quarts 0w40 Mobil 1 that was recommended by some engineer at https://bobistheoilguy.com/forums/
The engine is smoother, quieter and gets the same mileage. I run this in both the 2010 RX and 2016 Sienna with no issues. I change it every 5,000 miles or 1 year.

 

Hi Salim, you seem to be one of the subject matter experts here, so I was hoping for an elaboration given the following:
Most threads and youtube videos I've seen about oil viscosity claim that Toyota's recommendation of 0-20 is really more about meeting emissions/mpg goals than about doing what's best for the engine. They claim that going 5-30 would actually be better for the engine in the long run.

Are they wrong? If so, why?

 

One of the master techs at our local Lexus dealership has privately stated to me that full synthetic 5W-30 is a better choice for my wife's 2015 RX350 from a longevity standpoint. I have enough 0W-20 left to do one more oil & filter change at 120,000 miles. After that, I will be switching to 5W-30.

 

My Father had a 2010 Lexus ES350 which had the exact same 2GR-FE engine as my 2010 Lexus RX350, yet the ES350 calls for 5w30 oil and the RX350 calls for 0w20 oil. It is all about getting better gas mileage from the same engine in a larger, heavier vehicle that has more air resistance etc so they can claim slightly better corporate average fuel economy.
The 5w30 is specified for Lexus and Toyota vehicles with this engine in other warmer countries such as Australia or the Middle East that have different corporate average fuel economy reguirements (or none).

Just do what I do and blend in a couple of quarts of the same brand 0w40 with the 0w20 on those oil changes. You basically end up with 0w30.

 

Before any one else challenges this, I disqualify myself.

My opinion is the manufacturer knows the best [has done most extensive study] and for any claim they make (such as MPG) they have used certain fluids. So I am sticking with that till they change the guidelines. When Lexus Toyota only suggested oil weight based on climate, I used to purchase the narrowest spread in oil like 20W (winter) or 30W (summer). I am geared to stay away from modifiers that give the spread.

IMHO ppl overthink the situation. If the driving parameters are not extreme and the engine is not stressed (normal use), Quality 0W20 or 5W30 both will not harm the engine as long as the oil and filter are replaced regularly. If someone does the oil change more frequently, finds a better combination, or ultra-high-end racing engine oil, all the power to them.

FWIW I have not lost any vehicle due to my oil maintenance regimen and it was either due to accident or just trading for newer.

Salim

 

And to all of those people that say “manufacture knows best”, none of the counter arguments make them change their mind. It was mentioned several times that 2GR-FE used in Lexus ES350 2012 and older and Toyota Avalon of same years had 5w-30 in its manual.
The internal parts of 2GR-FE been compared between 0w-20 and 5w-30, and they have not changed to accommodate thinner oil, so please…

There are also foreign countries that sell same car have 5w-30. Some toyota manuals even suggest that thicker viscosity is more suitable when vehicle is operated at higher speeds or loads.
The thiner viscosity lets car makers get better MPG, so they can meet their CAFE requirements, thats all there is to it. The engines are designed to operate at viscosity range, this is necessary when engine started cold and oil viscosity is thicker.
Cafe requires them to put only one viscosity in the manual that gives best MPG. They are legally not allowed to put multiple viscosities. Thank CAFE and government

 

fromthe owners manual 2007 rx350 in australia. I use 10-40 on both rxs 276k kms and 250k kms

 

My 2015 RX350 has over 190k miles and I only use high quality Valvoline 0W-20 full synthetic high mileage oil. The engine does not burn oil and the engine runs like brand new.

Furthermore, when I pulled the front valve cover to replace the valve cover gasket and spark plug seals the engine was brand new looking on the inside with no visual sign of excessive wear on the camshaft lobes. 0W-20 oil works just fine with proper 5k mile oil change intervals. No need for any thicker viscosity oil in the 3.5 V6 engine.

Here is what my engine looked like under the valve cover with 5k miles oil changes and 0W-20 weight oil use with over 190k miles. No varnish and basically bare aluminum. Almost brand new.

 

Here is what people miss. While thiner oil “works” and people get higher milages on thinner, thicker oil provides more protection when its needed (such as towing or driving at high speeds). Its like extra insurance that you may not need depending on your driving, but good to have just in case. And btw, engine cleanliness has nothing to do with viscosity, its about how often you change oil and quality of oil.
The only reason 2GR-FE was moved to thinner oil is to meet CAFE standards, they made ZERO design changes, let it sink in ….