if your car calls for the 5w30 weight oil, would you hesitate to use the
10w30 in a climate with temps of 32 - 100=B0?I can't make myself believe that the recommendation of the motor car co.
- isn't self-serving.
m h o =A0v =83e
No.
I can't make myself believe that the recommendation of the motor car co.
- isn't self-serving.
m h o v fe
I would not hesitate to use 10w30. While I may be technologically outdated, I prefer a bit higher viscosity range. The lower range, if I understand correctly, is one of the ways that manufacturers achieve the mandated fuel economy ratings.
I wouldn't hesitate to use 10W30 if 5W30 was unavailable within those temperature parameters. However, it is my understanding that the engines specifying 5W30 have tighter bearing clearances and that using the 10W may have an adverse, if miniscule, effect on lubrication at lower temperatures. That being said, two of our cars specify 10W and two specify 5W so keeping some of both in the garage is no big deal.
That's true. But, there's a considerable amount of wear put on your engine starting it up cold. In cold climates, the better flow characteristics in cold weather of the 5w30 can help that a lot. In Florida, it won't make a damn bit of difference.
--scott
Trolling idiot.
As long as your engine is in good condition, and the cooling systme is functioning properly, there is no reason to think that there is an advantage to using 10W30 instead of 5W30. At the normal operating temeprature for your engine, they both have virtually the same viscosity. When the engine is cold, both are thicker than when the engine is warm. When cold, the 5W30 will flow better. The only possible reason for using 10W30 instead of 5W30 is becasue you are concerned that the 5W30 is more prone to break down. However, the usual affect of the oil breaking down is that it becomes thicker, not thinner. So I can't see any reason to use 10W30 instead of 5W30 unless you manufacturer specifically recommends the 10W3. It won't protect your engine better once the engine is warmed up and it is probably not as good as the 5W30 when the engine is cold.
Ed
wrote I can't make myself believe that the recommendation of the motor car co.
- isn't self-serving.
Yeah, you're right-on there brother. Go by horse.
Huw
what kind of car are we talking about?
Other way around. Viscosity index improvers allow the use of lighter (thinner) stock. It's the VI improver that determines the viscosity at normal running temperature, whereas the base stock determines viscosity at the cold end.
The rest of your argument stands. There's everything to gain and nothing to lose by using the oil with the lowest borderline pumping temperature (and hence the lowest viscosity when cold).
The 5W30 is also likely to use better quality VI improvers that are less likely to break down.
where did I read that the use of 5w30 oil as opposed to10w30 for the same car - reduced the life of
the car's engine by 30%, and only increased the fuel efficiency factor by a mere 1%?
I know now, in an article titled - all about motor oil.
m h o =A0v =83e
That's right.
The improver is long-chained molecules that stay in a little clump at low temperatures, and uncoil at higher temperatures.
There is another name for these molecules. When they form a solid mass, they are better known as rubber.
Yes, the viscosity improver is rubber, or something chemically related to it.
You can think of it as tiny particles of rubber which essentially start to melt at high temperature and mix with the oil, turning it to thicker goo. When the temperature drops, they revert to being dense little particles.
What makes you sure that it uses a /better/ quality viscosity additive, rather than just /more/ of the same one? Add more rubber, get more thickening.
These additives may add viscosity, but one thing they are not is lubricants. Corn syrup has viscosity, but it's not a terribly good lubricant (even for a cold machine) Thickness isn't everything, right?
Adding a rubber-like compound to oil is not going to make it slicker, only thicker.
If the engine and oil could be heated up to operating temperature without the engine actually turning over, then the best oil would be a straight non-multi-weight 30 (or maybe more) without any viscosity modifier.
Multi-weight is a compromise: trick to get a 5 or 10 to fake the thickness of a 30 when things heat up. A deeper spread is not better, it's just a bigger compromise to handle a greater temperature range.
For a spread greater than 10-30, I'd stick to synthetics. Supposedly, synthetics provide that multi-weight property without the viscosity improver additive, or need less of it to achieve a given spread.
Flame away ...
Why not take advantage of the thousands of cumulative years of experience the engineers and chemists at the oil and car companies have. I suspect they will have access to more information on the proper viscosity oil for a given motor in a given temperature range than anyopne on this news group. In other words just read the owners manual.
Can I ask why you want to use 10-30 rather than 5-30.
Is the car under warranty? If it's a new car and under warranty and you want to keep it that way, follow the manual.
If it's not under warranty, you can use anything you want. There are times when 0w30 is right and there are times when 20w50 is right.
Ray
Can I ask why you want to use 10-30 rather than 5-30.
This is always as safe an approach as you can get. Many owners manuals give you several choices depending upon the temperature range, type of driving, etc.
The 10w versus 5w doesn't mean a lot, most of the time. But if you are in a very cold climate, it might mean a little.
Thus you often see 0W-20 and 0W-30 products in synthetics.
The very 'best' Mobil1 grade is the 0w/40. 'Best' in the sense that it is suitable for much longer drain intervals and severe use than other M1 viscosity grades due to its superior chemistry.
Huw
Probably a little too simplistic. The VI improvers are long chain polymers which curl up (like a spring) as temperatures rise.
Long experience, with many applications, tells me that all VI improvers are far from equal. The common explanation is that the poorer quality polymers get chopped up by components such as gears where the better ones possibly survive. Better, and more expensive, oils tend to have better quality additives... this is probably particularly true of the more reputable synthetics.
Some manufacturers still don't trust any mutigrade oil because of the risk of VI breakdown in their machinery. AFAIK this still applies to Caterpillar (other than engines), and definitely to Briggs & Stratton engines. Cars and bikes that use the same oil for both engine and transmission are also at risk -- especially under arduous conditions such as racing.
Sure isn't. Contrary to popular opinion even natural viscosity has little to with the lubricating properties of an oil -- that's determined at the molecular layer level. Correct viscosity is about running clearances and obtaining correct flow rates. Too thin increases flow, often to the extent that piston rings can't handle the extra load. Too thick reduces flow, often to the extent that oil doesn't reach vital components.
The best oil would be one that had the same viscosity at all running temperatures. A straight grade is normally only the best option when there's a risk of VI improver breakdown.
Might be partly true but the multigrade synthetics also use VI improvers, albeit more expensive, and probably better quality ones. I might be wrong but I suspect that the better additives are also the ones that provide the highest viscosity index, rather than simply using more of the same thing. (The ones with the greatest number spread have the highest viscosity index -- ie 0W30 has a higher VI than 5W30, which is also higher than 10W30).
FWIW the second number relates to a viscosity range at 'normal' operating temperature. The first number relates to the borderline pumping temperature (below which it turns into a solid frozen chunk) and doesn't indicate an actual viscosity (contrary to popular opinion). In any case the SAE classification numbers aren't a viscosity scale as such.
Oops. My mistake... they uncurl as temperatures rise... which is as you've stated.
No argument about the effect, just don't much like the rubber analogy. :)
Safer than ...what...not following the owners manual????
Many owners manuals
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