Car Manufacturers and 5W20/5W30/10W30

[LarryM]

Do car makers recommend oils that help them make their EPA Fleet-weighted Fuel Economy numbers, instead of what's best for the engine?

I took a car that sold around the world, and checked with various oils companies web sites throughtout the world as to what the recommended oils were for that car. In the US the recommended oil was 5W30, second choice was 10W30, in the rest of the world I got numbers like 15W50, 5W40, 5W50. Leads one to wonder - the engines were all made in Japan, and I doubt that the US engine is made to different tolerances than the Australian engine, for example.

 

[metroplex]

Do not use 5W-20

stick with 5W-30 or 10W-30 and you'll be fine.

 

[Al]

I think its a given that 5W20 is CAFE motivated so as to be able to sell more gas hogs. I would not use 5W-20 in a million years.

 

[jjbula]

quote:

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Originally posted by LarryM:
Do car makers recommend oils that help them make their EPA Fleet-weighted Fuel Economy numbers, instead of what's best for the engine?

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You hit the nail on the head. Any engine that recommends 5w20 can use 5w30 or 0w30. Just look at the spec sheet at the thickness of the oil at 100C.

The lower or first number is what to worry about during engine warmup. The oil is much thicker at 40C and below.

The challenge is using a thick enough oil at operating temp to prevent wear. Many argue a 0w40 or 5w40 is ideal. Until analysis shows me too much wear I'll stick with a 5w30.

 

[richard612]

I'm still waiting to hear which oils are recommended for that 4.3l export Blazer. For the US, it's that typical 5W-30-but-you-can-use-10W-30-if-you-insist stuff...

 

[sprintman]

LarryM
Same cars here as the U.S, Japan just put them on a different boat Consider this, Mobil 1 0W30 or 5W30 not sold here, Mobil said it's useless. 20W50 outsells every other viscosity here combined. 0/5W40 IMHO is almost the ideal for any engine/condition you can think of but hey the rest of the world could be all wrong and U.S style 5W20/30 is the best? It just ain't the oil I want in my cars, I want 15-20yrs outa them.

 

[Mark in NY]

There has been a lot of talk about the EPA influence in mandating 5-30 and recently 5-20 vs what some believe to be better for engine life, -0-40 or 20-50 etc.
Has anybody ever considered that the reason the zinc and phosphorus levels are being reduced is that the manufacturers are anticipating higher wear rates and resulting higher oil burn rates - pushing more oil past the converters- due to the thinner oils being used?
I think these 2 trends might be related.
Any thoughts, or better yet, anyone know if this question has been put to the manufacturers??

 

[dragboat]

One of our members posted his findings on the subject and was nice enough to forward it all to me. In a letter written it appeared to be a test to see if the consumers would adhere to the owners manual recommendations. The EPA wants to know how much 5/20 oil was sold and at what price for a certain period and then it seemed to say they would decide if they will extend that past the year 2004. You guys with those cars are giunie pigs imo,rather your motors are making for one of the least desirable years of used cars ever made to puchase used unless very carefull owners had the vehicle.

Let your consiense be your guide but IMO I would use another oil

 

[jjbula]

quote:

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Originally posted by Mark in NY:
Has anybody ever considered that the reason the zinc and phosphorus levels are being reduced is that the manufacturers are anticipating higher wear rates and resulting higher oil burn rates - pushing more oil past the converters- due to the thinner oils being used?

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My understanding is some engines with thinner oils consume more oil. Does it indicates higher wear or just looser tolerances? Do we have to put more cleaners in the gas/oil to compensate? Either way, I don't like it.

Adding a quart or two of oil during 5K just to get 2% bettter mileage is not good.

You may have noticed that the brand name 5w20's use Moly as an additive.

 

[dragboat]

My thoughts are the oil is too thin which will increase wear on a engine built the same as always as in no tolerence changes. Later,will ask my Wife to type the page sent to me,it tells me it is merely a test by the EPA. I will post it in the Interesting Articles Secton because it is fairly long

 

[jjbula]

quote:

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Originally posted by sprintman:
LarryM
Same cars here as the U.S, Japan just put them on a different boat Consider this, Mobil 1 0W30 or 5W30 not sold here, Mobil said it's useless. 20W50 outsells every other viscosity here combined. 0/5W40 IMHO is almost the ideal for any engine/condition you can think of but hey the rest of the world could be all wrong and U.S style 5W20/30 is the best? It just ain't the oil I want in my cars, I want 15-20yrs outa them.

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I've read your posts on this before. I can hardly believe the 20w50 thing (so different than what I've experienced). A couple of years ago, I thought 5w30 was Mobil 1's flagship product. I should have been using 15w50. But that was before 0w40, Newer VII's, Group II/II+, moly, and SuperSyn. (Schaeffer was probably using moly then)

How cold does it get during the summer or winter by you?

As GeorgeCLS says, "That's what makes oil exciting"

 

[dickwells]

In my observation, actually in imported cars specifically, use of 15-50 M1 will cause oil seal failure in some significant proportion of the cars. At least those driven in Illinois. RW

 

[Jay]

Do the 20 weight oil bashers here really know what you are talking about? If you say you would never use a 20 weight oil then how do you know it's that bad?

My Acura RSX came with dino 5w-20 as the factory-fill oil and it performed very well. Mobil 1's 30 weight oils are almost 20 weight right out of the bottle. I think the first Mobil 1 oil was 20 weight and 20 weight only.

Show me an oil analysis with 0w-20 or 5w-20 that had bad results. In fact, show me several. I'd like to see them.

 

[jjbula]

quote:

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Originally posted by Jay:
Do the 20 weight oil bashers here really know what you are talking about? If you say you would never use a 20 weight oil then how do you know it's that bad?

Show me an oil analysis with 0w-20 or 5w-20 that had bad results. In fact, show me several. I'd like to see them.

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You may be right on Jay. My thoughts are not based on any analysis. But I have an open mind (really). However I'm not going to test 5w20 in my car.

Can you test yours the next time you change? Maybe your results will help change our minds.

Otherwise we are stuck with me saying prove it works and you saying prove it doesn't

 

[Jay]

My 5,000 mi analysis on the factory-fill 5w-20 was posted here by Troy Heagy. This is break-in oil however, so the wear-metal numbers don't mean much. I'm running M1 0w-30 now but I'm unhappy with the consumption I'm getting with it. I'm changing the oil soon and I have M1 5w-30 already on-hand. If my consumption is high with the 5w-30 I'm going back to 5w-20 or 0w-20. I'm not the only RSX owner who has had higher oil consumption with 30 weight than 20 weight.

 

[sprintman]

jjbula
Changed out my 2nd lot of Auto-Rx/dino this morning and needed some additional dino for after cleaning seal hardening. BP is my local servo and all they had in dino was Castrol GTX2 20W-50, GTX3 15W50, BP Corse Plus 25W60, Visco 2000 20W50, Visco 3000 15W50, and a Castrol 10W40 blend called Magnatec. They are a large and very busy servo but not a drop of 0/5/10W30 to be found. So shock horror I bought the Castrol GTX2 20W50 SL dino as 2 litres added to 2 litres Pennzoil 10W30 SL PureBASE I had already gives me I hope a 15W40 straight dino. Will be glad to get it out and a straight syn in there though as quick as possible as I don't like the idea of dino in a turbo engine but I'm following the Auto-Rx rules to the letter. And even though I have a very clean engine the PureONE filter was full of crap again, so bad the lifters were real noisy.

 

[jjbula]

quote:

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Originally posted by Jay:
I'm running M1 0w-30 now but I'm unhappy with the consumption I'm getting with it. I'm changing the oil soon and I have M1 5w-30 already on-hand. If my consumption is high with the 5w-30 I'm going back to 5w-20 or 0w-20. I'm not the only RSX owner who has had higher oil consumption with 30 weight than 20 weight.

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I hope the wear goes down after break in. I also hope the recent oil consumption is not a result of the break in.