Recommend an oil choice to me - used 2005 Highlander V6

[Rock_Hound]

My ‘03 Avalon has the predecessor engine: 1MZ-fe. It is a great family of engines.

If it hasn’t had a timing belt change, you are due for one. Every 100k/decade, I do the timing belt, water pump, cam seals, valve cover gaskets, and spark plugs. These motors will run forever if you keep these things up.

As for oil, I have been changing with a quality full synthetic (Mobile 1, Valvoline, Pennzoil, I am not to picky) and a Toyota YZZn1 (or f1, or d1) filter every 5k miles. I know that is probably overkill, but oil changes are cheap, and it gets me under the car often enough that I can spot any maintenance that will need done before it becomes a problem. Maintenance is cheaper than new car payments.

 

[JohnnyJohnson]

Hi all. Just purchased a very nice 2005 Highlander V6 3.3L. 125k miles and impeccable carfax with regular 5k oil changes - most at dealerships, but some at other quick lube places. The seller indicates dino oil was likely used although the last oil change was supposedly hybrid oil. 5W 30 is recommended in the manual. Two issues I wanted to note: 1) the valve cover gasket is leaking in case that impacts oil choice votes. 2) In the oil filler "neck" area, I noted the metal "baffle" has a hard carbon-like oil coating that most folks on the mechanical board didn't find concerning, nor did a reputable shop that I had inspect the car. But I can't help but wonder if perhaps I should look at an oil that might have better cleaning power than others.

I'm partial to Mobil. So am thinking:
1. Mobil 1 5W-30 full synthetic
2. Mobl 1 5W-30 High Mileage - full synthetic
3. Mobil Super 5000 synthetic blend
4. Mobil Super conventional

Years ago, folks claimed switching to full synthetic could cause oil leaks and I think this is the origin of the Mobil1 1 HM version that supposedly has additives that help swell seals to avoid leads. Any issues with using straight Mobil 1? Consider the HM version? Go with a blend (considering conventional has likely been used in the car since 2005) to be on the safe side yet still get synthetic qualities, or just stick with a good quality conventional like Mobil Super and be mindful of the 5k change intervals.

TIA in advance oil gurus for any and all input!

Switched my 2004 Toyota to full synthetic at 66,000 miles drove it for 16 plus years it never leaked or used much oil. Burned about a 1/2 cup in 5000 + mile OCI's.

 

[Chris142]

what has worked for the last 20 years?

 

[Intelligent Molecule]

Have the same engine in my 2005 Sienna, but with 267k miles on the clock.

Introduced regular Mobil1 to it awhile back after a lifetime of synblend changed at 5k miles without fail. Started to leak within weeks-pretty substantial leaking.

Changed out to Valvoline Maxlife blend, and it stopped the leaking completely in a fairly short amount of time. This isn't the first time this has happened to me with high mileage vehicles.

Your engine is a lot fresher than mine was, so maybe it won't be a problem. But it seems like very little to gain and something to lose with a switch at this point.

 

[Dorian]

First off, great car and underrated engine. While I wouldn’t hesitate to run M1 0W40 in that pup, I would actually give Valvoline Restore and Protect a good run to clean things up a bit. Though I will say, the biggest difference we noticed with ours was running it on mid grade. Loads more torque and better mpg.