[code]In david's case, is it adviseable to run some dino to first break in an engine, then switch to synth if you want. I though something on here once said that the extra friction helps to seat things better.
Jason
</pre><hr></blockquote>

Yes, I will run Dino for 2000 miles then switch to synthetic.

 

[quote]Originally posted by MBuck951:
<strong>I use nothing but synthetic Redline 20W50 in my turbo now. The pressure stays much higher and more consistent than with Mobil 1 15W50, especially on the track. Pressure used to drop below 2 coming outta turn 2 at Summit Point, now its around 4 with the Redline.

mike
88 951
91 S2</strong><hr></blockquote>

Ahh.. ANOTHER Mobil 1 story... interesting...

Sorry... couldn't resist... I'm just not a big fan of Mobil 1... AMSOIL and Redline get my vote...

 

I recently switched to synthetic and noticed that my oil pressure peaks and averages a lot higher than before also (between 4 and 5 bar).

What would explain this change?

84 944

 

Synthetic oil has much less reduction in viscosity with increasing temperature, and that's why the oil pressure stays higher. In the 1980's, I had a 1962 V-12 F------, and switching to AGIP synthetic as the factory recommended at that time increased hot oil pressure by about 10 psi.

 

I've posted some pretty long replies both here and over at Pelican.

There is no real reason your seals should start leaking as long as the viscosity range is the same. Most people (at least here in the south) run 20-50 dyno and change every 3K mi. I switched to 20-50 synthetic (Valvoline makes it) so I could extend the change intervals out to 5K (very reasonable with a synthetic) so save time and hassle factor: I have had no leakage. I have noticed a little more presure after warm up (the synthetic may be more stable at temperature). I'm not sure but what some people, in switching, use a synthetic that has a little LESS viscosity at temperature (like a 5-30 or 10-40W) leading to possible leaks.

A higher pressure (using the same viscosity oil) would be indicitive of a higher viscosity (more stable at temperature), and thus Less likely to leak!

 

I've been recently convinced that even 15/50 may be too high. If you think about it, when changing from 10/30 to say 15/50 the oil is thicker and would therefore create more backpressure on the system (thus the higher pressure read-out). When creating higher oil pressure, does that not mean that there is more backpressure in the system so not as much oil is getting through the motor at a time? In that regards, would the oil stopped up in the system then cycle through the oil cooler later and at a higher temperature?
-Robert D.

 

The oil is for all practical purposes an incompressible fluid. The flow rate is set by the pump but the pressure will change with viscosity. 20-50 is standard for southern area -- 10-40 or so up north (0-30 in Dead Horse Alaska).

The point being that you should be running 2.5-3 bar after the engine is warmed up (at idle mine is spot on 3 bar) -- the meter will be pegged at start-up (where the viscosity is at the lower number of the oil's range anyway). After warm-up the oil is at the highr viscosity number (in my case 50).

I'm here in Ft. Worth --not too far from Austin... 20-50 is just nearly perfect! For all practical purposes there is not much difference between 20-50 and 15-50 -- does your car have trouble turning over when cold (that's nearly 80 degrees out at what... 6AM! here in TX!) -- that's the only place (at start up) that there might be some precieved difference between those two oils.

 

When considering a switch (up ) to Redline, carefully read the site information before making a grade selection. I now run Redline 10W30, with no worry of increased wear with lower weight, and no worries of crank whipping.

Also, Redline is a complete car thing, if you wish it. Mine has Redline Oil, Transaxle fluid, PS Fluid, Water Wetter, and Injector Treatment.

Good Luck!

Skip

 

[quote]Originally posted by David Floyd:
<strong>Adrial,

What do you think of the Amsoil ?

I am undecided on which oil for my new 2.8 (almost done with the install)Mobil 1, Redline or Amsoil. Mobil is the only one I can buy local, I want to use the best so the extra trouble of ordering is ok if need be.

Have you installed the test pipe yet ?</strong><hr></blockquote>

Well im not sure what to say...its nice and easy to order direct from their website..I usually get a few of the gallon jugs of 20-50 racing for the summer and 10-40 for the winter. I still change every 3k miles, although they say you can go WAY WAY longer than that before a change.

As far as how it performs...I didn't notice any change in oil pressure from 20-50 dino castrol to 20-50 amsoil synthetic....none that I could determine from the factory gauge anyway. Today after 16 runs of autox (2 drivers, 50 sec runs about) and a 85 degree day, oil pressure was down to about 2.2 bar at idle...typical is 3 bar after normal driving.

As I'm sure you know...run dino until its broken in...

I haven't installed the test pipe yet, will hopefully get to that when I head home this weekend...I thing I'll see flames out the exhaust. wheeeee

--Adrial

 

THE VERY week I put in dino oil instead of the usual mobile 1, my valve stem seals went toast on me

 

i run mobil 1 15w-50, and my car leaks oil from everywhere. i'm too paranoid to switch to dino with 145k on my car, i'm sure as soon as i do my rod bearings will fail, pistons will sieze, turbo will burst into flames and rear shocks will start leaking....

 

[quote]Originally posted by dave120:
<strong>Synthetic has been used in my S2 since day 1..I don't plan on switching anytime soon...engine has 145k on the clock and still running like brand new. But I'm not an expert on the subject so I dunno what the ups and downs of each are, except that I haven't ever heard of synthetic causing problems in anything old or new..</strong>

ditto mobil1 in mine, 91 s2 cabe with 102 on the clock

<hr></blockquote>

 

hi guys,

my 87 s has been using non-synthetic oil since it has been in my possession. i am pretty sure that the previous owners (2) also ran traditional fluids.

in the summer months here in delaware, it stays pretty damn hot, so i go with agip 15-40 supplied by my mechanic. if the car is a little low i bring to level with castrol between changes. changed every 3000 on the dot, not a single leak anywhere.

i have considered going either full or partially synthetic, but after reading so many comments about sudden leaks, i think i will stick with "dino" oil - unless someone can give me one hell of a good reason to switch.

 

Here's really good article on Dino vs Synthetic - for Turbo cars, I'll stick with synthetics

<a href="http://www.pelicanparts.com/techarticles/mult_gas_and_oil/mult_oil_article.htm" target="_blank">http://www.pelicanparts.com/techarticles/mult_gas_and_oil/mult_oil_article.htm</a>