Been away from Yotatech for a while so thought I would drop by and give a long term test result from running a thicker oil.

After seeing that they spec thicker oil for the Prado that has the same 5VZ-FE engine in it, I started running mine with Valvoline 15W-40 diesel oil at around 40K miles. Now my runner is at 340K miles with 300,000 of those mile running the heavier oil at 6K oil changes.

Now I'm in the Houston area so we don't get much colder than 35F but our summers are like hell only with humidity. So far I can go 6K on oil changes and not have to add any oil. I also recently changed the valve cover gaskets and the top end was very clean with zero signs of any deposits.

Once warmed up the oil pressure at idle with A/C on on a hot day is around 12 psi and at 70 mph its around 42 psi.

With the 5VZFE having a flat tappet camshaft it can benefit from a thicker oil especially in hot weather. I know some will say the manual says 5W-30 and a engineer did that for a reason. If it was for any other reason besides CAFE standards then why do they spec the PARDO 5VZ-FE for thicker oil?

On a side note aside from the drivers side power door lock motor and the power antenna motor I have not had any other problems with my Runner and hope to get another couple hundred thousands out of her.


FOG

 

What kind of driving was most of your driving ??

Traffic jam rush hour??

Or state roads with little traffic.

As long as your getting enough oil up top at start up and with those miles you must be.

I think your right about the reason why the 5/30 is recommended in the USA.

Most Engineers are over paid idiots

I always ran 85/140 gear oil in all the gear boxes .

 

Interesting, didn't realize the overseas 5vzfe motors were spec'd for 15w-30 oil. I'm not an expert on the subject, but I thought you didn't want a heavy oil in DOHC motors in order to get the oil up to the cams quicker.

How does a lighter weight oil help with CAFE standards? Don't say fuel economy because running heavy or light weight oil I've never seen a difference.

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My driving is a mix. My morning commute is often just open highway because I'm out before traffic. My drive home is stop and go in afternoon heat.

As far as CAFE standards yes thinner oil in a lab test environment does get better mileage on paper but not in the real world.

With a DOHC you do want oil to the top end but the 5VZFE is kinda a odd duck for the year it was made. Most modern engines have roller rockers that have a wheel the rides on the lobes of the camshaft our engine doesn't.

Instead we have the camshaft lobes rubbing directly against flat surface of lifter. Because of this extreme pressure you need a thicker oil film.

In defense of engineers I think they are doing what they are told. You have the engineer saying it needs thicker oil but the bean counter says we can boost our CAFE avg with this thin oil.

Fog

 

I'm surprised your cats have survived. Diesel oil is hell on catalytic converters...

There was a big push to use Diesel oil in the 60 and 80 series land cruisers about 10 years ago. It seems they have to either go without or replace their cats.

Good to see this is not the case across the board on all Toyota's...

 

Just why would Engine oil effect the Cats unless you were burning a quart per 100 miles??

I am looking to learn something new.

 

I live in DC and the Outer Banks for the duration of the year and have used nothing but 10w-30 Valvoline in mine since 2006. No complaints here but it now burns roughly 1/2qt every 5,000 miles due to old valve stem seals, which will be replaced next spring hopefully.

+1 on why the diesel oil would be so bad for the cats? My uncle ran Rotella in his 4.6 3v f150 for twelve years with no replacement of the cats. He had four diesel tractors, so he purchased the oil in bulk.

 

315,000+ here. Castrol GTX 5w/30 since the day I purchased it.

I'm happily riding this POS to 400,000 or more.



Andreas

 

My 2015 Ford 550 6.7 Power stroke has a Cat

Just what oil do I use if I can`t use 15W-40 even Ford says to use that type my head hurts!!

 

The high zinc content in the diesel oil was taking out the cats. It was plugging up the cats and causing high pressure up the system. A lot of folk were experiencing overheating due to the cats starting to plug up.

Diesel cats are designed for it...

 

FWIW, I've ran 5w40 Rotella T6 in my motorcycles for years. Twins, thumpers, inlines, and the diesel has always shined.

 

My question is how does all the oil get into the exhaust??

It matters not if your getting that much oil unburned into the exhaust you have a major problem

Even burning that much oil does one carry a 55 gallon drum for the 10 mile trip to buy groceries??

 

It sounds like a fluke native to those landcruisers only...maybe?

 

This is correct. The high zinc content is what kills the cats. Diesels do not have catalytic converters so the zinc is ok.

It's not uncommon for lots of higher mileage engines on the road to burn a quart or so of oil between change intervals. Burning that amount of oil with high zinc is enough to kill the cat over time.

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