Something interesting I've learned from the PJ

[snakecharmer]

Mod motors warm up their oil slowly. Very slowly. :) I've never had a Mustang with an oil temp gauge on it before, so it has been interesting for me to note that the coolant temp comes up very quickly, while the oil takes significantly longer. I always knew this was the case with any engine (the Vette has an oil temp readout in the DIC and the M3 turns off it's moving yellow-line on the tach based on the oil temp readout). However, the Mustang is noticeably slower than the other two coming up to operating temperature with the oil. Like nearly twice as long. I have no reason to think the gauge is not accurate, as once it does come up to temperature, it reads right where I would expect (around 175 degrees) in normal driving. The noticeable sluggishness coming up to temperature makes me wonder if this is another reason Ford wants thin oil in their modulars (Saleen, however, calls for 5w30 full synthetic in the Parnelli, not 5w20). It especially strikes me as curious given the Bimmer uses sludge by comparison (10w60!).

I share this only as an example, and the thing I have "learned" watching it on the new car is to change my habits for how long I drive a mod motor before I consider it warm enough and safe enough for me to hit the loud pedal full force. I will be adding a oil temp gauge to the 97 as well.

FWIW,

E.

[CAMELEON]

Here is something I have now learned ..... Motor oil is like every other fluid in that its viscosity varies with temperature and pressure. Since the conditions under which most automobiles will be operated can be anticipated, the behavior of motor oil can be specified in advance. In the United States, the organization that sets the standards for performance of motor oils is the Society of Automotive Engineers (SAE). The SAE numbering scheme describes the behavior of motor oils under low and high temperature conditions -- conditions that correspond to starting and operating temperatures. The first number, which is always followed by the letter W, describes the low temperature behavior of the oil at start up while the second number describes the high temperature behavior of the oil after the engine has been running for some time. Lower SAE numbers describe oils that are meant to be used under lower temperatures. Oils with low SAE numbers are generally less viscous or runnier than oils with high SAE numbers, which tend to be thicker.

So, for cold weather startups, the 5w20 and 5w30 perform the same ..... I think

[Ruby SVT]

Very interesting....! I guess my Ol' Granp Pap knew waht he was talking about when he told me to let the car warm up a good while before mashing my foot through the floor! What smart Ol Turd he was, wish I have paid more attention to what he tried to teach me!

[Vnemous]

Remember, the less the resistance caused by thick oil, the better the full economy rating. Could it be this small difference helps the car companies meet their corporate average fuel economy rquirements? from what I have read, this play a part. Some engine also need that thinner oil with the tighter tolerances nowdays....