Oil Viscosity, CAFE, and your Taco Engine

You aren't getting it and you're not going to get it. That's okay. Stop cluttering up this thread please.

 

So I have been looking at the first chart. One thing I do not understand is why does 5w-30 cover less of an area in the high temp range as 10w-30. They are both supposed to be 30 weight oils when fully warmed up, so why does toyota say 5w-30 is only good up to 50 F where as 10w-30 is listed up to 100+ F.

 

It's a Toyota. Change the oil every 5k miles with synthetic 5W-30 and the truck will last you 400k miles.

Biggest difference between the US and other countries is not only the environmental regulations- but also the legal environment. Toyota has corporate lawyers who get paid through the nose to make sure they are covered on all ends. I bet you the manual only states one oil for the US because it is the safest and best use oil- and it will keep them from getting sued by some idiot who uses the wrong oil in his engine. Sorry OP, Toyota has engineers who know whats best for your truck better than what you think is best for your truck- that goes for all of us.

 

See post #3 in this thread.

Toyota's engineers for the AU market don't count I guess? Keep your head in the sand.

 

Sparky, I'm typing this slowly.

If you read it slowly, maybe you'll understand.

I live in the U.S.

I choose to follow Toyota's recommendations for where I live.

 

Also interesting that in the diesel, 5w-30 is fine for the whole range.

 

The U.S. has the dumbest, most ridiculous environmental regulations on the planet for many reasons I won't go into. Those that "get it" on this forum will know what I mean. The regulations in this country are B.S. That being said, running a thicker oil won't hurt a thing depending on where you live. I run a 10-30 100% synthetic in southern Wyoming. If I lived where it is hot I'd run the same or a 0-40, 5-40 and I if towed a lot where it is hot I might run a 15-40. 5-30 is recommended for the first gens. That's a recommendation. It's not set in stone. I run a 100% synthetic in Southern Wyoming where it can get very cold. The second and 3rd gens recommend thinner oils. Engines with VVT need "special" oils. You just have to research this stuff but IMHO a thicker film inside the engine is the best for longevity especially if the engine is worked hard. VVT does cause a problem with that theory though and when I own a VVT engine I'll be looking into that. That will be in another year or so.

 

The 1GR-FE doesn't have a problem with a range of oil weights - including 5W-30 and 20W-50 - according to Toyota of Australia.

 

Sparky, thank you for teaching us so much about Australia.

Got a serious question for 'ya. Why do they drive on the wrong side of the road in Australia?

Supposedly, here's why.

https://www.carmudi.com.ph/journal/whats-the-reason-behind-right-hand-driving-in-some-countries/

 

That fist chart is a weird one. Millions of people are using 5-30 all the way up to 120 degrees in many makes of cars. As a matter of fact probably in temps even higher than 120 degrees.

I use 10-30 for a number of reasons but one of them is that the closer the numbers are the more stable the viscosity. They don't have to use as many VI's (viscosity improvers) to make it work. Fewer VI's result in a more stable viscosity, less chance of sludge and oil thickening as the miles pile up on the oil.

Amsoil actually makes a straight 30 weight that performs a lot like a 10-30. I'd be giving that a try if I lived in a warmer climate. Thin oils are only for CAFE standards. Not engine protection which is why countries everywhere else are running thicker oils.

Picture VI's like a centipede rolled up in a little circle. If you take a match to the centipede it will unwind. That's how the molecules VI's are made of work. Add heat and they unwind. Thickening the oil.

I'd be running a straight weight if I could but these modern engines and ambient temps up north just make it pretty much make it a fools game. Multi-viscosity oils really are superior in this day and age unless you have rather unique circumstances and temps.

 

There was a poster on this forum I came across a long time ago that had been running 15-40 in his engine and he had a lot of miles. He wasn't in a "cold" state. I have to wonder if the extremely high milers are running a heavier oil. I'm talking about the guys that are getting 5 or 600,000 and even close to a million miles out of their engines. There was the courier guy who had just under a million miles on his 2.7 and the Tundra guy who had around 900,000 on his. What weight were they running? What was their maintenance schedule? Considering what they do for a living with the engine constantly running with most of it being highway would add to the longevity but knowledge of their maintenance schedules and what products they used would paint a clearer picture.

I'm just wondering if using thicker oils may make these engines run far longer than the 3 or 400,000 miles so many get out of them. Nothing gets beat worse than a Las Vegas taxi cab and they kept the old Crown Victorias up to around 350,000 miles and more. Many with an engine and rear end rebuild in there somewhere. One driver told me the only reason they got rid of them was because the interiors got so trashed after that many miles. I believe they run Mobil 1 in them and probably the recommended 5-30 or 0-20.

Me? I've always run the thickest oil I can get away with based on ambient temps for my local. If I lived in Phoenix, AZ I would probably be running a 15-40 or a 20-50 especially if I was towing or hauling heavy loads. As cool as my 2.7 runs I can't see going above a 30 weight where I live. Even in the summer time.

 

You kind of answered your own question there, 10W-30 can be better than 5W-30 in high temps because the viscosity doesn't break down as fast or as much.

But to add to it - 0, 5, 10, 15, 20, 30, 40, 50 weight oils - these aren't a fixed point in terms of viscosity. They're a range and at the ends of the range they meet. It's possible to have a 5W-30 that's really close to a 0W-40 for instance. If you take a look at the viscosity numbers for (say) regular Full Synthetic Mobil 1 5W-30 and High Mileage Mobil 1 5W-30, you will see that they're not identical and the High Mileage is thicker. And when it comes to 10W-30 vs 5W-30, the "30" part of the grade is likely thicker in a 10W-30 than a 5W-30.

See my other posts on the first page - manufacturers used to specify ambient temperature ranges for 5W-30 and 10W-30 like this routinely.

The problem with all of these anecdotes is that they have no statistical value from which to draw a conclusion.

With a large enough sample size, if you knew the number of engines that made it to (say) 300,000 miles running 5W-30 and the number of engines that made it that far running 10W-40, you could draw a conclusion.

But also with a large enough sample size (and Tacomas are certainly that) you will have people getting to 300,000 miles or more on a 4.0L 1GR-FE with 0W-20. Just because it happened once or ten times doesn't mean that the rate is high - there could be another 10,000 that didn't make it.

I'm willing to trust what Toyota is allowed to recommend in AU where CAFE doesn't exist, which is that a thicker oil is perfectly fine in these engines.

 

Do they serve Kangaroo in an Australian Cafe?

 

The oil filler cap says 5w30. But I can't find 5w30 anywhere. I live in Costa Rica and none of the automotive supply stores have 5w30. They carry 10w30, 10w40, 15w40 but no 5w30. The truck was manufactured in Mexico, but the manual is similar to the one printed in the U.S. in regards to the oil and temperature ranges.
The coolest temperature l have seen where l live is 65°F at night. With the hottest being about 95°F in the dry season. .
l just grab 10w30 and change it myself.

 

Geez, if you live in Costa Rica put 10-30 in it. You'll never have a problem with the temps in that part of the world. 10-40 would work and even 15-40. Don't worry about it.

 

I was looking at the new 2019 Rav 4s and there using 0w16 oil.

 

Sparky, You have an opinion. I have an opinion. The big difference between them is that my opinion counts.

 

This is definitely one of the most informative oil posts that I have read here.

Thanks OP

 

The first number is only really important for cold start protection (think snow on the ground) which you don't need to worry about.

So 10W30 or an even thicker oil will do you just fine where you live. I'd say the AU manual would be a good guide to go by based on your ambient temps.