Oils that our cars DON'T eat?

[AZP Installs]

Yeah, they are now allowing 5-30 and 5-40 but as you said, no where does it allow 0-40 in the specs. I also agree that it was probably not the cause of your engine failure, they could have used it as a loophole on the warranty.

 

-mike

[seabass07]

A 0w40 might be too thick during the winter months. If the oil caused any problems, going up to a 5 or 10w40 would make the problems worse. A 0w30 may be better. They have no idea what they are talking about. 0 is better for winter. Going up to a 40 may be too high for very cold weather.

[joeblow]

If the car runs fine on a 40 in the summer, it'll run fine on a 40 in the winter. The engine temperatures that the oil is gonna see aren't going to be a whole lot different at full operating temp in the winter or summer.

[AShoe]

Anyone that says a 0w-40 is too thick for the winter, or too thin doesn't understand oils. It is both thicker than a 5w-30 at operating temperatures, and thinner at start-up. It flows easier and provides better protection. Like joeblow said regardless of summer or winter engine operating temperatures will be within a few degrees of each other unless you have a cooling system problem. Start-up is what matters and a 0w-xx oil will flow better at start-up regardless of whether it is summer or winter.

[seabass07]

I've never driven in a real winter...so that's good to know. I do understand oils, but I always assumed that oil and coolant temps would be kept a lot cooler due to the radiator keeping the coolant cold. That would make a 40 a bit too thick. But I guess with the thermostat closed, it wouldn't work that way. Thanks for the correction.

[AZP Installs]

The first number represents the flowability/thickness of the oil when not at operating temps. The second number represents the thickness/flowability when at operating temps.

 

The 0 weight is not recommended for our cars IIRC because it will flow past the rings/valves when cold and therefore you will end up consuming more oil. The 0 weight is for cars that have tighter tolerances than our cars have. Thicker oil such as 10w40 will be too thick on the pre-warmup side and cause excessive wear when cold.

 

The 30 is the recommended weight for the operating side of things but a 40 weight is good for track and warmer climates because it stays thicker at higher operating temps.

 

-mike

[seabass07]

But if the oil will not flow past the rings at operating temperature, then it sure as hell will not flow past the rings when cold and the viscosity is MUCH higher. When it is a "0" it is much thicker than when it is a "40". They are different scales.

[itsme]

been using penzoil 5w30 (dino) from the very beginning with no oil consumption.

+1

[dmanaenk]

1.5k miles on PP. Looks full to me so far.

[0Tyrael0]

Im sorry but I just have to say something.

 

1. Thin oil is better in every single way. There is absolutely no reason to use thicker oil other than perhaps price.

2. 0w does not determine the weight at startup. For example 0w20 and 0w40 have very different weights at startup.

3. If your consuming oil dont use thicker oil just get it fixed. It will save you money in the long run.

4. 0w40 is thicker than 5w30 all the time no matter the temp

5. These numbers are different than people think. They are just a representation of how much the viscosity changes after heating up. This is not the viscosity of the oil.

[0Tyrael0]

Where do you get this from?

 

Regardless of the brand, 0w40 oil in general are thicker than a 5w30 in warmer temps. They are thicker at 40C and 100C, just thinner in extreme cold. This is the case with mobil1. With mobil 1, the 0w40 is thicker than the 10w30 above 40C.

 

0w40 is thicker than 10w30 all the time.

[0Tyrael0]

But the viscosity at cold temps is still much thicker than at operating temperature. How could it be too thin if the viscosity is several times higher than at operating temp? IMO, the closer to the operating temp viscosity the oil is in cold weather, the better it will flow and the better it will be on cold starts.

 

This is 100% correct.

[0Tyrael0]

I had a warranty long block replacement and had to provide proof of oil changes via receipts. They noted that I used 0w40 during the winter and gave me a bit of grief for having done so. Luckily in the end they explained that while it could have been the reason for the engine failure, they couldn't prove it, and not to use it in the future.

 

They did the warranty long block and returned the car with several pages from a manual showing that a 0 weight oil was not recommended anywhere. It also included some schematics and engine clearance numbers etc. They were fairly adamant about this point and I've just used 5w30 since despite being mostly sure that the 0w40 had nothing to do with my engine failure.

 

I dont doubt it 0w40 is too thick. Its thicker than the factory recommends which is bad. Thick oil is bad.

[0Tyrael0]

A 0w40 might be too thick during the winter months. If the oil caused any problems, going up to a 5 or 10w40 would make the problems worse. A 0w30 may be better. They have no idea what they are talking about. 0 is better for winter. Going up to a 40 may be too high for very cold weather.

 

99% correct. 0 weight oil is better all the time.

[0Tyrael0]

Anyone that says a 0w-40 is too thick for the winter, or too thin doesn't understand oils. It is both thicker than a 5w-30 at operating temperatures, and thinner at start-up. It flows easier and provides better protection. Like joeblow said regardless of summer or winter engine operating temperatures will be within a few degrees of each other unless you have a cooling system problem. Start-up is what matters and a 0w-xx oil will flow better at start-up regardless of whether it is summer or winter.

 

0w40 is thicker than 5w30 all the time. No matter the temp.

[0Tyrael0]

The first number represents the flowability/thickness of the oil when not at operating temps. The second number represents the thickness/flowability when at operating temps.

 

The 0 weight is not recommended for our cars IIRC because it will flow past the rings/valves when cold and therefore you will end up consuming more oil. The 0 weight is for cars that have tighter tolerances than our cars have. Thicker oil such as 10w40 will be too thick on the pre-warmup side and cause excessive wear when cold.

 

The 30 is the recommended weight for the operating side of things but a 40 weight is good for track and warmer climates because it stays thicker at higher operating temps.

 

-mike

Not trying to be an a$$ but your engine would have to be like 130 degrees C to justify a 40 weight oil. Again 0w30 and 0w40 are totally different. 0 is not the weight of the oil at startup.

[0Tyrael0]

But if the oil will not flow past the rings at operating temperature, then it sure as hell will not flow past the rings when cold and the viscosity is MUCH higher. When it is a "0" it is much thicker than when it is a "40". They are different scales.

 

Again 100% correct. you do understand oils.

[0Tyrael0]

Im done with my rant. Sorry cant help it. Im not trying to call anyone stupid or be a jerk I am just trying to stop the spread of false info. Thats what forums are all about. Spreading good and hopefully correct information. I respect everyones opinion and will gladly answer any objections to my posts. I have talked about this with car experts. I am no expert I this is only what I have learned from my experience with cars and my own research. Also here is an excellent site run by a car expert. He also has a lot of money and time to conduct experiments to answer these types of debates.

 

http://www.supramania.com/aehaas/

 

Also this doesnt mean you should use the thinnest oil possible. You obviously need to find the best oil for what you use your car for street/track just street, just track and so on. In my opinion the best weight for our cars (turbo and NA) and almost all cars is 0w30 or if you insist 5w30. A 0w40 might actually be ok if you are running very hot on the track. Whatever brand. Im not here to argue about brands because thats another story.

 

O and one last thing the weights I mentioned only apply to synthetic oils. The only real reason synthetic oil is better is because its thinner. 5w30 synthetic is quite a bit thinner than 5w30 dyno oil at all temps.

[katalyst]

this thread is mega lol, esp the last few pages

[0Tyrael0]

Lol im glad you like it.

[seabass07]

0Tyrael0. A 0w40 from some brands will be similar to a 10w30 at 40C and thicker than a 30 at 100C. Sometimes the 0w40 will be closer to a 15w30 at 40C and thicker at a high temp. You are right however that at all temps a 0w40 will be thicker than a 0w30. It is not that cut and dry. It is a range, but ranges overlap, especially when comparing dino and synthetic oils. Many 0w40s will have a lower pour point than a 5w30, even if the 5w30 is synthetic.

 

Oh and subaru recommends a 5w40 for hot weather or hard driving.

[apexi]

0w40 is thicker than 10w30 all the time.

 

Not true. That's the whole reason why 0w oils are recommended for cars which see extreme cold conditions, because the 0w oils are thinner than 5w and 10w oils at freezing temperatures.

[BAC5.2]

At 30k miles, I don't lose a drop of Motul 8100 in the 5W40 flavor with 3000-4500 OCI's.

[johnAWD]

I'm having good luck with 'German' Castrol 0w30. I was a longtime Mobil 1 user until this car, which showed a tendency to eat Mobil 1. I did my 3rd oil change with the Castrol last weekend, and after 4000 miles I was around 1/4 qt down. The car has just under 64k on the clock.

[AShoe]

I'm having good luck with 'German' Castrol 0w30. I was a longtime Mobil 1 user until this car, which showed a tendency to eat Mobil 1. I did my 3rd oil change with the Castrol last weekend, and after 4000 miles I was around 1/4 qt down. The car has just under 64k on the clock.

 

Where do you find it? I used to use the German Castrol, but haven't been able to find any recently.

 

To clear up the weight argument (maybe), The first number is the oil's "winter". It indicates the viscosity of the oil at 0 degrees F. The second number is the viscosity at 210 degrees F. In other words a 5w-30 acts like a 5 weight oil at 0 F and a 30 weight at 210 F. A 0w-40 acts like a 0 weight at 0 F and a 40 weight at 210 F. The friction modifiers work in different ways at the temperatures in between and every oil is thinner at hot temperatures than it is when cold. A 0w-40 is thinner than a 5w-30 at 0 degrees F. At what temperature it becomes thicker varies from oil to oil, but at 0 any 0w-xx is thinner than any 5w-xx oil. Of course all this varies from brand to brand and oil to oil.