Rotella T6

   / Rotella T6 #21  
15w40 is thicker oil at startup (when cold) than 0w40. What if a particular manufacturer requires a thicker oil at startup? Then it wouldn't meet their specifications.
 
   / Rotella T6
  • Thread Starter
#22  
I drive school bus for a large district. We have over 100 buses, most of which are kept outside. The fleet is maintained strickly with 15w40 dino oil. The buses are on a timed block heater starting October when the weather gets cold. Most of our fleet has a 100,000 miles or more. They are very good at stay on top of preventative maitainance. I do see the garage rebuilding a motor now and then. I'm not pitching non synthetic oil but it looks like staying on top of regular maintainance is more important than just changing oil.
 
   / Rotella T6 #23  
I use T6 in my 3320 for about 2years and it starts well at 6-8 deg weather we are having rite now BOB
 
   / Rotella T6 #24  
15w40 is thicker oil at startup (when cold) than 0w40. What if a particular manufacturer requires a thicker oil at startup? Then it wouldn't meet their specifications.
No non ignorant mfg would say that. ALL oils thin as they heat. At operating T a 0W40 oil is thinner than it is when cold. -- But when cold it flows like a cold 0 weight oil and quickly reaches all engine parts. A 5W40 only flows like a cold 5 weight; slower to get where needed. -- A 15W40 sucks by comparison because it pumps slower in the cold. NO ENGINE needs a thicker oil starting than it does running, it just needs instant flow.

Synthetic base stocks are superior, giving them a more stable viscosity naturally. Dino oils require more additives to accomplish this. -- A 5W40 is relatively easy using synthetic stock. ... Watch out if you see this spread in a Dino - its more additive and less oil. ... Not so good.
larry
 
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   / Rotella T6 #25  
I have been using T6 for 5 years, 600+ hours and year round. Change it every 100 hours and it starts great at zero degrees.

Started using T6 since the first change at 50 hours. 800 plus hours now. Works good in the Winter temps and the Summer. Still change at every 100 hours.
You guys are essentially running a constant flush cycle. If you were closer Id come get your changeout "rinses" and even pay you for them.
larry
 
   / Rotella T6 #26  
I have used T6 Rotella in both my tractors since new (first oil change). My tractor never has any issues w/ leaks or starting in any weather. In fact, I've been in CT since Sept. helping out my elderly parents (took tractor) and it always starts regardless of how cold it is. The only thing I do is use a Deltran battery tender as the battery gets weak in colder weather.
 
   / Rotella T6 #27  
Think you got that backwards, basically 15w40 viscosity is 15 weight at <100 F and 40 weight at >100 F.

Actually you have something backwards, either your equality signs or viscosity thinking. Your statement reads "15W40 is 15 weight at less than 100F and 40 weight at greater than 100F" Viscosity (resistance to flow) increases as temperature decreases. So any oil is thicker at cold temps, and thinner at high temps. The XXW part is how thick the oil is a low temps, the lower the number, the thinner the oil is. So the lower the W rating, the better it is in cold temps.
 
   / Rotella T6 #28  
I'm not much on "OIL THREADS"! but I'd like to have yer Rotella cap points, so I can cash them in. You guys wasting oil via 100 hour changes could make some serious headway on Shell points! I'll pay the pstg. too.

It's true that certain problematic seals can develop leakage when using full syn oils but I'm not suggesting these tractors are "that" machine. A widely held viewpoint for some models of BMW motorcycles with rear wheel bearing seal problems is to avoid full syn gear oil back there and go with dino.
 
   / Rotella T6 #29  
Actually you have something backwards, either your equality signs or viscosity thinking. Your statement reads "15W40 is 15 weight at less than 100F and 40 weight at greater than 100F" Viscosity (resistance to flow) increases as temperature decreases. So any oil is thicker at cold temps, and thinner at high temps. The XXW part is how thick the oil is a low temps, the lower the number, the thinner the oil is. So the lower the W rating, the better it is in cold temps.

Long time reader, first time poster here. I thought I would clear up a few things about oil. First of all, most people think the "W" in oil stands for "Weight", but it actually stands for "Winter". So, a 15W40 oil indicates a 15W winter weight, and a 40 operational weight. These two weight "types" have different viscosity properties, so a 15W weight oil does not have the same viscosity vs temperature as a 15 weight oil.

So, the following is typically true about oil viscosity: 0W<5W<10W<15W @ 0C. I say typically, because the second number can impact the viscosity of the first. :) If the second number is the same, then this statement is always true.

As for the second number, the following is always true about the viscosity: 20<30<40<50. So at operational temperatures, the higher the number, the higher the viscosity.

In the case of a 5W40 or 15W40 oil, the cold starting (0C) viscosity of 5W or 15W weight is always HIGHER than the operating temperature of 40 weight oil at operational temperature. So the oil viscosity for 10W40 is as follows: 10W @ 0C > 40 @ 100C.

So as far as seals, and part tolerances, it is important to make sure the second number always meets manufacture's recommendations. This ensures the oil isn't too thin at operational temperatures, which could push through seals of moving parts with poor tolerances and seals.

As for the first number, you can typically go lower, especially in colder states. The only thing to make sure of is that the "Winter Weight" viscosity isn't higher than the running weight, which I've never seen. Just keep in mind that the two numbers really have nothing in common. 15W weight does not equal 15 weight oil. It simply means WINTER Weight vs Operation Temperature Weight. Operational viscosity typically flattens out over 100C.

Here are some oil viscosity charts to digest, and give you a better visual of what I'm trying portray. :)
Engine oil ? viscosity table and viscosity chart
 
   / Rotella T6 #30  
Long time reader, first time poster here. I thought I would clear up a few things about oil. First of all, most people think the "W" in oil stands for "Weight", but it actually stands for "Winter". So, a 15W40 oil indicates a 15W winter weight, and a 40 operational weight. These two weight "types" have different viscosity properties, so a 15W weight oil does not have the same viscosity vs temperature as a 15 weight oil.

So, the following is typically true about oil viscosity: 0W<5W<10W<15W @ 0C. I say typically, because the second number can impact the viscosity of the first. :) If the second number is the same, then this statement is always true.

As for the second number, the following is always true about the viscosity: 20<30<40<50. So at operational temperatures, the higher the number, the higher the viscosity.

In the case of a 5W40 or 15W40 oil, the cold starting (0C) viscosity of 5W or 15W weight is always HIGHER than the operating temperature of 40 weight oil at operational temperature. So the oil viscosity for 10W40 is as follows: 10W @ 0C > 40 @ 100C.

So as far as seals, and part tolerances, it is important to make sure the second number always meets manufacture's recommendations. This ensures the oil isn't too thin at operational temperatures, which could push through seals of moving parts with poor tolerances and seals.

As for the first number, you can typically go lower, especially in colder states. The only thing to make sure of is that the "Winter Weight" viscosity isn't higher than the running weight, which I've never seen. Just keep in mind that the two numbers really have nothing in common. 15W weight does not equal 15 weight oil. It simply means WINTER Weight vs Operation Temperature Weight. Operational viscosity typically flattens out over 100C.

Here are some oil viscosity charts to digest, and give you a better visual of what I'm trying portray. :)
Engine oil ? viscosity table and viscosity chart

Hi teswanson and welcome.
Nice write-up. Should clarify the info for a lot of people.
 

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