BTW, on a dyno. the HP difference between a 0/20 synthetic and a 20/50 is about 2-3 tops on a Chevy V8.

That would be a brand new Blueprinted and tight drag motor.

 

I use M1 0W40.

 

In another forum I caught him trying to argue water wasn't wet and the sun isn't really all that hot.

 

I wouldn't use 15w40, I tried 10w40 when I first got my car and the first hot day at idle I noticed my pressure just above one bar at idle in gear. I have generic 5w50 synthetic now and on a normal hot day I am at 1.5 - 2 bar idle in gear when temp it as the last white line. I will probably go with Mobil 1 15w50 synthetic next oil change.

 

Been using 10w40 Amsoil and at hot idle in traffic on a 95 Degree day the car holds just below 2 bar. Fast starts and no lifter noise.

 

I have noticed that most poeple who use synthetic oil for any period of time have one thing in common. They know what the inside of their engine looks like.

 

??? Good or Bad?


I did an inspection teardown on a 125k synthetic-only 4cyl car I had, and found all the original hone marks in the cylinders and no ridge at all. Cams and associated gear looked brand new, not even a yellow film on them after cleaning. Same with my V-6 Explorer when it needed a head gasket at 150k. Did they last longer with synthetic? It takes a destructive test to find out.

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Run a too-low viscosity oil and you'll find out a lot of things. Oil pressure with thin oil, synthetic or conventional doesn't mean all the bearings have adequate flow or film. As Greg points out, the OP could easily have some rubbing and not know until it's too late. Why would anyone risk this on purpose?

 

Given the choice, I'd prefer not to see inside my engine.

 

And your the guy gunning for 320 rwhp in a 25 year old car that was rated for much less?

Didn't check the rod bearings before?

You'll see it soon enough.

 

From what I've read, the Kendall "green oil" brand was purchased by Conoco / Phillips.
What was Kendall Racing oil is now Brad Penn.

 

And you actually state this like you want people to think that this is a good thing?

Tell you what, get that oil up to those temps and then let the car idle for 20-30 minutes with the A/C running, like you are in traffic, and let me know how things turn out.

 

This pretty much says everything.

 

I will simply never understand why some people feel the need to put thinner oil into the 928 than is specified in the owner's manual. Most 15W-50 and 20W-50 synthetic oils these days pour well down to 15 - 20 deg F. If you don't live somewhere where you will be under this temperature range most of the time and still drive the car, what are you trying to improve with the thinner oil? Lower fuel consumption? More power? Both are negligible, unless the engine is specifically designed to run with it...

Dan
'91 928GT S/C 475hp/460lb.ft

 

Rotella is revered by many because of stellar used oil analyses. Oil is high in zinc, and is a heavy duty oil designed for over-the-road trucks. So car the 82 is responding to it very well.

My owners manual does not declare 20w50 as the preferred weight.

 

So you're claiming that synthetic oil in general destroys engines? Wow.