Oil Viscosity

[pg4323]

I am brand new to this forum but am an old geezer with a question.

My local Toyota dealer service people told me it is wrong to use a thicker oil when the engine has 135,000 miles on it than the normal 10w30 they put in all cars.

This goes against my understanding and reasoning. I thought as an engine wears, rings, bearings etc a 10w-40 might be considered to cushion areas that have worn and to help protect against metal to metal contact. Also reducing blow by, by making a better seal between the piston rings and the cylinders.

Am I wrong?

 

[Tempest]

If your car uses little or no oil with the oil it is spec'd for, continue to use it. If you use a lot oil, then consider to go up a grade.

 

[Quest]

Originally Posted By: pg4323
I am brand new to this forum but am an old geezer with a question.

My local Toyota dealer service people told me it is wrong to use a thicker oil when the engine has 135,000 miles on it than the normal 10w30 they put in all cars.

This goes against my understanding and reasoning. I thought as an engine wears, rings, bearings etc a 10w-40 might be considered to cushion areas that have worn and to help protect against metal to metal contact. Also reducing blow by, by making a better seal between the piston rings and the cylinders.

Am I wrong?


In addition to Tempest's advise, the truth is (as a former mech), engine manufactured during the past 30 yrs or so are much better in regards to wear and tear: less cylinder tapering due to improper metallurgy, better lubrication formulation to further reduce ring related wear and sludge/carbon formation, etc.

In other words: unless your engine is in terrible shape to begin with (worn bearings due to improper loading, dirt ingestion, bad oil grade/OCI, maintenance, etc.) otherwise, you do not need to up a grade or 2 to keep the "so-called" engine wear at bay (just stay with whatever grade your automotive manufacturer recommends).

Switching 1 grade up is so "old school" that I have not seen this being done for quite a long time (at least 18+yrs). In case you wonder: there's something called HM (high-mileage) oil of the same viscosity grade as what your engine manufacturer recommends that you can use on an aging engine to keep it in ship-shape.

Q.

 

[Pablo]

Pretty much, yes you are. But I heard a so-called pro on the radio puke say the same.

What year is your Toyota? Why not 5w30?

 

[mitchcoyote]

I'd recommend Valvoline Maxlife 10w30.

 

[Merkava_4]

Originally Posted By: pg4323
This goes against my understanding and reasoning. I thought as an engine wears, rings, bearings etc a 10w-40 might be considered to cushion areas that have worn and to help protect against metal to metal contact. Also reducing blow by, by making a better seal between the piston rings and the cylinders.


Your way of thinking is is just right for a 1970 Chevy 350 (or a similar engine of that era) since they were not manufactured to the precise tolerances of today's engines. Modern day engines also don't wear as quickly because of their rollerized low friction valvetrains.

A high mileage 10w30 will be thicker than a regular 10w30, but not as thick as a 10W-40.

I'd recommend a high mileage 10w30.

 

[ChiTDI]

pg - I'd question that dealer's advice for the simple reason of using 10w30 for all of its cars!
Toyotas spec 5w20, 5w30, and possibly other viscosities as well. They're violating the manufacturer's warranties!

 

[3putter]

I would just go with a high mileage oil like Maxlife or Penz Bronze Bottle and stick with the 10w30. The High Mileage oils are a bit more robust, and sound perfect for your application.

 

[coffee]

Or you could run a phase of AutoRx and then use Pennzoil Platinum 10w30 afterwards. The High Mileage oils could be a good option as well.

 

[jorton]

WELCOME!

Since you've used this practice before, I have a question for you. In a car with high miles and hydraulic lifters does the 10w-40 quiet the brief knocking sound that comes when the engine is started cold?

 

[TallPaul]

Originally Posted By: pg4323

My local Toyota dealer service people told me it is wrong to use a thicker oil when the engine has 135,000 miles on it than the normal 10w30 they put in all cars.


That's very nice that they use 10w30. I would stick with the 10w30 unless you have low oil pressure, then you might try a 10w40.

 

[jorton]

Originally Posted By: pg4323
10w-30 they put in all cars.


I'm sure the manufacturer approved the dealerships' 10w30. Everyone knows dealers choose it because some customers cars are high mileage.

 

[MolaKule]

Quote:
In a car with high miles and hydraulic lifters does the 10w-40 quiet the brief knocking sound that comes when the engine is started cold?


Not necessarily; if you have an engine with offset wrist pins or weird piston skirts (yes a free design feature) then no.

I always recommend going up to an High Mileage oil in the same viscosity grade or use a bio-synthetic oil before jumping up one viscosity grade.