What oil are you guys running in your turbo cars??
10-16-2015, 10:59 AM
#101
You would be surprised just how minuet the difference between 15w30 and 15w50 is. Once these oils reach operating temperatures the viscosity differences aren't even close to what your describing. As said earlier everyone had a prefrence.. IMO The only people who should be picking apart oil selection are the guys who live up north and drive their cars in sub 30* weather.
There is some evidence that here in Florida at least, people running a thick 20W-50 in their .0012" clearance 122 cubic inch engines seem to spin rod bearings more often, and have more oil pump failures, and whether the pump failures are due to the bearing trash, or the other way around, I can not say for sure. My aim was only to provide possible situations in which you might want a different oil i.e. if you car will be race tracked all day in 90*F Weather, you probably will not want a 10W-30 oil regardless of how tight the engine is.
10-16-2015, 11:42 AM
#102
My example was theoretical, mystical (made up) and not intended to be a real-world example. I do not have engine oil pressure flow charts handy, nor would I know where to find such things. Perhaps I should start looking for them. And fwiw the numbers on the bottles do mean something, that is, a 30 on the end means that the engine oil will be no thinner than a 30 at a specific temperature, and so forth, meaning that although our eyes and brains may not be able to tell the "minuet difference" you describe, I assure you our engines can tell.
There is some evidence that here in Florida at least, people running a thick 20W-50 in their .0012" clearance 122 cubic inch engines seem to spin rod bearings more often, and have more oil pump failures, and whether the pump failures are due to the bearing trash, or the other way around, I can not say for sure. My aim was only to provide possible situations in which you might want a different oil i.e. if you car will be race tracked all day in 90*F Weather, you probably will not want a 10W-30 oil regardless of how tight the engine is.
There is some evidence that here in Florida at least, people running a thick 20W-50 in their .0012" clearance 122 cubic inch engines seem to spin rod bearings more often, and have more oil pump failures, and whether the pump failures are due to the bearing trash, or the other way around, I can not say for sure. My aim was only to provide possible situations in which you might want a different oil i.e. if you car will be race tracked all day in 90*F Weather, you probably will not want a 10W-30 oil regardless of how tight the engine is.
Last edited by oscs; 10-16-2015 at 01:20 PM.
10-16-2015, 02:59 PM
#103
I agree on the one condition that the vehicle be a daily driver. You must realize that high performance engines with larger tolerances use a thicker oil, and therefore, the statement above is useless in those instances. That is what I was getting at with those examples.
