Synthetic oil choice

[livehho]

As I understand, as the additives wear out (in dino oils) the oil reverts to its true weight, the lower number, 5 in case of a 5w-30 for example.. that's why it's recommended a higher weight number, so it does not get very thing as the additives wear out. That makes total sense. IN THE OTHER HAND, synthetics have very little additives; therefore, they do not thicken much when cold nor thin much when hot... so...

So my question is: Would there be a problem in using a full synthetic 5W-50 in hot weather? and have the best of both worlds?

- protect engine wear at strart-up (5w)
- protect engine wear at operating temps (50)

So it will flow much faster than a conventional dino motor oil during initial start-up, yet at normal operating temperatures it will act like a regular Grade 50 oil.

I know that in hot weather it's recommended a 15w or 20w.. but if you use full 100% synthetic (AMSOIL, Mobil 1) you could use a much lower W number to help the engine at start up.

 

[bepperb]

Yes.

Oils don't really shear (or get thinner) towards their winter viscosity rating, they just get thinner as they age (generally) until the dispersants in them wear out and they become prone to sludge.

Sure, you could run a syn 5-50 in hot weather, and get similar protection to what a 20w-50 would give you with the obvious advantage of easier starting.

 

[d00df00d]

Originally Posted By: livehho
So my question is: Would there be a problem in using a full synthetic 5W-50 in hot weather? and have the best of both worlds?

- protect engine wear at strart-up (5w)
- protect engine wear at operating temps (50)

Sorta kinda.

The W number only means how it flows when it's REALLY cold. When it's 80+ degrees out, a 5w-50 will probably still be thicker at start-up than a 5w-30.

Also, thicker doesn't always mean it will protect better. What does your car normally take?


EDIT: By the way,

to BITOG!

 

[hate2work]

Just use the grade your engine calls for. Thicker oil will not protect better in hot weather. Your oil pretty much stays the same temp whether it's 40F outside or 100F outside.

 

[livehho]

Originally Posted By: bepperb
Yes.

Oils don't really shear (or get thinner) towards their winter viscosity rating, they just get thinner as they age (generally) until the dispersants in them wear out and they become prone to sludge.

Sure, you could run a syn 5-50 in hot weather, and get similar protection to what a 20w-50 would give you with the obvious advantage of easier starting.


thanks. so why are there synthetic grades higher than 5w in the market? no need...

why would you wanna put a 15w in your engine when you can use 0w or 5w and make it easier for the engine at start up.

 

[CATERHAM]

In interpreting an SAE multi-grade oil you cannot analyze the two number separately.
Using your examples a 5W-30 is a much lighter oil at start-up than a 5W-50. To get an idea of how think or thin any oil is refer to the PDS info that is readily available on line from most oil manufacturers.
M1 5W-30 has a 40C vis of 64.8 cSt while their 5W-50 40C vis is 105 cSt; very much a thicker oil. The 5W-50 does have a somewhat higher VI than the 5W-30, nevertheless even at 0C the 5W-50 will be about 60% heavier.

 

[livehho]

Originally Posted By: d00df00d
Originally Posted By: livehho
So my question is: Would there be a problem in using a full synthetic 5W-50 in hot weather? and have the best of both worlds?

- protect engine wear at strart-up (5w)
- protect engine wear at operating temps (50)

Sorta kinda.

The W number only means how it flows when it's REALLY cold. When it's 80+ degrees out, a 5w-50 will probably still be thicker at start-up than a 5w-30.

Also, thicker doesn't always mean it will protect better. What does your car normally take?


EDIT: By the way,

to BITOG!


ahhhh.. but they don't tell you that do they..? so in hot weather the low number doesn't mean much I guess. thanks for the info. NOW I UNDERSTAND.

BTW, thanks for the welcome message. My ride is a Toy 2.4L 4cyl 120K mls. I've been using 20w-50 since I bought it about 6 months ago. No leaks whatsoever but oil gets burned very quick. 2000 miles and it's already dark brown. that's why i want to change to synthetic.

 

[livehho]

Originally Posted By: CATERHAM
In interpreting an SAE multi-grade oil you cannot analyze the two number separately.
Using your examples a 5W-30 is a much lighter oil at start-up than a 5W-50. To get an idea of how think or thin any oil is refer to the PDS info that is readily available on line from most oil manufacturers.
M1 5W-30 has a 40C vis of 64.8 cSt while their 5W-50 40C vis is 105 cSt; very much a thicker oil. The 5W-50 does have a somewhat higher VI than the 5W-30, nevertheless even at 0C the 5W-50 will be about 60% heavier.


my car's filler cap says 10w-30.. I've never used that grade cause everybody has advised me to use 20w-50. But this is what happens. Specially at morning when engine is cold I hear a clacking noise at startup. It disappears after 2-3 secs or when I rev it up. I'm sure it's the [censored] timing chain and this what I think is happening. The stock 22RE toyota oil filter uses a check valve so when you shut off your engine, oil remains in the filter. When you go to start the engine, oil is already compressed so the tensioner already has pressure applied to the timing chain. Im using [censored] FRAM filter. The FRAM has no oil in it because it drains out when the motor is shut off. Thus, when you go to start the motor, oil has to build up and initially, there is no pressure applied to the timing chain. I'm sure that is where the clack, clack, clack comes from.

 

[hounddog]

That 20w50 is murder on a engine at cold startup.Use whats on the cap.10w30.

 

[hostile]

Originally Posted By: livehho
No leaks whatsoever but oil gets burned very quick. 2000 miles and it's already dark brown. that's why i want to change to synthetic.


The colour of it has nothing to do with how well it is or is not protecting your engine.

 

[nfs480]

Originally Posted By: livehho
Originally Posted By: CATERHAM
In interpreting an SAE multi-grade oil you cannot analyze the two number separately.
Using your examples a 5W-30 is a much lighter oil at start-up than a 5W-50. To get an idea of how think or thin any oil is refer to the PDS info that is readily available on line from most oil manufacturers.
M1 5W-30 has a 40C vis of 64.8 cSt while their 5W-50 40C vis is 105 cSt; very much a thicker oil. The 5W-50 does have a somewhat higher VI than the 5W-30, nevertheless even at 0C the 5W-50 will be about 60% heavier.


my car's filler cap says 10w-30.. I've never used that grade cause everybody has advised me to use 20w-50. But this is what happens. Specially at morning when engine is cold I hear a clacking noise at startup. It disappears after 2-3 secs or when I rev it up. I'm sure it's the [censored] timing chain and this what I think is happening. The stock 22RE toyota oil filter uses a check valve so when you shut off your engine, oil remains in the filter. When you go to start the engine, oil is already compressed so the tensioner already has pressure applied to the timing chain. Im using [censored] FRAM filter. The FRAM has no oil in it because it drains out when the motor is shut off. Thus, when you go to start the motor, oil has to build up and initially, there is no pressure applied to the timing chain. I'm sure that is where the clack, clack, clack comes from.


Sigh, why are people so afraid of using what the manufacturer recommends in their vehicle? Everyone's an engineer these days.

 

[d00df00d]

Originally Posted By: livehho
ahhhh.. but they don't tell you that do they..? so in hot weather the low number doesn't mean much I guess.

For cold flow, no.

Now, in a roundabout way, the DIFFERENCE between the low number and the high number might tell you a thing or two. In general, the smaller the difference, the tougher the oil, all else equal. It usually doesn't matter for street-driven cars, though.


Originally Posted By: livehho
BTW, thanks for the welcome message. My ride is a Toy 2.4L 4cyl 120K mls. I've been using 20w-50 since I bought it about 6 months ago. No leaks whatsoever but oil gets burned very quick. 2000 miles and it's already dark brown. that's why i want to change to synthetic.

Don't worry about the color. Some people have their oil turn black as night within 1,000 miles and never have a problem; others have it come out nice and clear but end up with premature wear. If you really want to know how your oil is doing, order an oil analysis kit and send it away so people in lab coats can tell you.

 

[d00df00d]

Originally Posted By: livehho
my car's filler cap says 10w-30.. I've never used that grade cause everybody has advised me to use 20w-50. But this is what happens. Specially at morning when engine is cold I hear a clacking noise at startup. It disappears after 2-3 secs or when I rev it up.

Oh wow. Don't use a 20w-50, then. If I were you, I'd use a good synthetic 5w-30 or 0w-30 year-round.

Also, definitely get a better filter.

That combo should work a lot better for you.

Why do people recommend 20w-50? Is there a reason, or is it the same old "makes my engine quieter/always used it/so-and-so swears by it/I've never had a problem with it" stuff you always hear?

 

[RTexasF]

Friend you have really been fed some bad "knowledge" about oils in general.

Quote:
As I understand, as the additives wear out (in dino oils) the oil reverts to its true weight, the lower number, 5 in case of a 5w-30 for example

That is not correct. An oil may shear over time such as a 30 weight oil dropping to a 20 weight but not the lowest number.

Quote:
my car's filler cap says 10w-30.. I've never used that grade cause everybody has advised me to use 20w-50

Quit listening to "everybody" because they are giving you some really bad information.! Try listening to Toyota ie 5W30 or 10W30.

Quote:
2000 miles and it's already dark brown. that's why i want to change to synthetic.

As mentioned previously the color of the oil means nothing, it can be black as pitch and still doing its job perfectly. Ever see the oil color in a diesel?

Quote:
Specially at morning when engine is cold I hear a clacking noise at startup

Did it occur to you that the oil you are using may be causing the clacking noise at startup because it's too heavy for that 2.4l ??

Stick around here, do some reading.......there are some knowledgeable folks here. Stop listening to whoever you have been talking to because they are sorely lacking in knowledge and aren't helping your car one bit! If you are willing to learn then you have come to the right place.

 

[Johnny]

I agree with everything RTexasF said. Well put.

 

[Doug Hillary]

Hi,
nfs480 _ You said this:
"Sigh, why are people so afraid of using what the manufacturer recommends in their vehicle? Everyone's an engineer these days."

Such simple words of wisdom - I have been telling that to Fleet Engineers and others as a Consultant for about 40-50 years - but the "expert" amateur Engineers always know best!

Wow - the money I have seen trashed by Fleets and others, and the Warranty claims denied from not heeding "your" simple words of wisdom is truely enormous!

Good stuff!

 

[livehho]

I'm changing oil and filter this friday and will report back the results. Will change the cr@ppy FRAM filter for a Purolator. Regarding the oil I'm probably going for 5W-30 or 10W-30. I think I will try a blend first, and if no leaks, I will go for a full synthetic like AMSOIL or Mobil 1. After reading quite some articles it seems that oil leaks seem to be a common problem when switching to full synthetic in hi-mileage vehicles. Here is one explanation:

"On older vehicles which have been lubricated with petroleum oils, seals and gaskets can begin to dry and crack. The reason you don't actually see leaks is because petroleum oils tend to burn off and leave sludge, grime and varnish on the inside of your engine. That's simply the nature of a petroleum oil's make-up. Now, conventional petroleum oils are not very discriminatory about where they leave those deposits. Therefore, some of the deposits end up around your seals and gaskets which actually plugs up the gaps which would have resulted in oil leaks. (...) ..there are also other additives that give a synthetic oil its detergency properties. In other words, there's other stuff in high quality synthetic oil which tends to clean out the sludge and deposits left behind by petroleum oils. Once these deposits are gone, the gaps around seals and gaskets become exposed and the oil might begin to leak in these areas."

source: http://bestsyntheticoil.com/info/seals.shtml

So I guess friday I will find out the real reason why my engine doesn't have oil leaks.

- my engine gaskets are in very good condition or
- the oil sludge has plugged up the existing gaps.

One thing seems sure though, if it's the latter I can forget about switching to full synt. At least until I change the faulty gaskets anyway.

 

[livehho]

Originally Posted By: RTexasF
Stick around here, do some reading.......there are some knowledgeable folks here. Stop listening to whoever you have been talking to because they are sorely lacking in knowledge and aren't helping your car one bit! If you are willing to learn then you have come to the right place.



Yea man.. it's crazy stuff. All the info, articles, mechanic advice, forums.. they all give you their truth. Pure dogma. It can drive you nuts sometimes. So many questions. You always get half of the story. I wish there was some 'motor oil bible' or something. Some centralized information source about everything you need to know about this topic. That would really really help I think. This site looks completely devoted to motor oil so that's a good start.

 

[mechtech2]

The 5 rating is only for 0 deg F. Sure, many of us see those temps or lower, but they are only a few days .
It will be thicker after that in the intermediate range of temperatures until it reaches it's 50 rating at 212F.

So 5-50 going to be much thicker than 5-30 in almost all conditions.

 

[Rand]

5 isnt a viscosity rating its a number referencing its low temperature pumpability at -30C(or is it -35C?)( for 5w-XX)

viscosity is very complicated and not easy to wrap your head around.

a 5w20 is thicker at 40C than a 20w50 at 100C... much thicker.

etc. Oil Viscosity ratings/numbers is one of those numbers that is misunderstood by most people.


Tire ratings are another.. The whole speed rating vs handling

or aspect ratio vs height... sigh.