I agree, I never run the car hard before the temperature gauge is up. The car feels quicker when the engine is cold though.

 

60% of engine wear occurs in your driveway at startup, after it has sat all night, and the oil has drained to the CC.

Couple that, with the fact after it has been run for awhile, using multigrade 5W20, when it is up to temp, it is now thicker.
If you shut it off, let it sit for 15 mins, and restart, you are now pumping thicker oil to the top of the motor. So even when it's warmed-up, you should always let it idle, and slow throttle at first, to get the thicker oil to where it needs to be.

 

Lejay, Oil viscosity DECREASES as it gets warmer. Haven't you ever changed the oil at ambient temp versus hot? Which one flows easier? Hot oil flows like water whereas cold oil is much thicker. When starting a cold engine the oil is the most viscous and less capable of getting into areas with very tight tolerances for proper lubrication. This is the main reason it's important to let the engine get up to proper operating temperature before getting on it.
Many people that live in cold climates start their cars, go back inside, and let the car sit there with the engine racing. This is the worst thing for the car. It's best to just start it up and drive off slowly until properly warmed.
Engine tolerances today are extremely tight which is why most cars now use 5-20 W oil. I use to use 20-50 W not to many years ago. That would kill a car in short order today.

 

SORRY, BM, you have it totally backwards.
So you are saying 90 gear oil is thinner than 5 ?
There is no such thing as 20-50 W.
Do you know what the "W" means ?
5W20 oil came about to meet Cafe Standards, it has nothing to do with tolerances.
5W is MAXIMUM pumping viscosity.
WE run 20W50 in all our race engines, if you want to talk about "tight tolerances"

Look it up.

 

it doesn't matter who is right to me because LEEJAYS been wrong before it wouldn't suprise me if he is again......

 

I've read a few posts on other tech forums of people exploding their engines becuause they beat on them before they were at operating temp. I always let mine get to temp before ripping it up.

 

Where did I say 90W oil is thinner than 5W? I said oil gets thinner and less viscous (you said it gets thicker) as a direct relationship to increase in temperature and that is a fact. You're the one who needs to do some research pal. Excuse me for not putting the W between the numbers but I think every educated person here figured it out. As a chemist I've personally run thousands of viscosity studies and tests on numerous chemical compounds (including silicone based oils) that I developed in the laboratory. I worked on cutting edge technologies with top synthetic chemists from Amoco Oil at my last work place. The only oil that will thicken with an increase in temperature is that which has decomposed and polymerized. I think it's called SLUDGE and it's not something I want in my engine. Here's some pics of me at work if you think I'm full of it. Do you even know how viscosity is measured? Aren't you the guy that wanted to make a Swiss cheese out of a stock air box? I still have mine for sale btw. Oh, that's right, I remember now. Your friends told you it wasn't a good idea so you gave up on the idea.

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[IMG]local://upfiles/38400/577D5A39E3704F87B9C3B9ADBA08CC3B.jpg[/IMG]

 

WHOA [sm=owned.gif]


lol That's awesome...

 

UR still wrong, especially about not letting a car warm up in cold weather. I Don't believe for 1 min ur a chemist.
In a 5W30 the VISCOSITY INCREASES AS IT GETS WARMER. LOOK IT UP EINSTEIN.
C'mon, don't evade the "W" question.
You also said 90W, there is no such thing as a 90W.

U R so full of sh**

 

UMMM.........Lejay I hate to say this but YOUR WRONG.....I know it's hard to admit but "look it up Einstein"

EVIDENCE IN BLACK AND WHITE