From old posts: SAE Congress - I reviewed articles from the SAE conferences on power train and fluid systems in Tampa, Fl of October 2004 and the Paris 2000 conference. See SAE SP-1894 and SP-1550. Here are some excepts: A New Method of Measuring Aeration and Deaeration of Fluids, Morgan et al: Air in oil causes oxidation, wasted power, higher oil temperatures, loss of lubricity among other adverse effects. Higher RPM increases aeration, so does increasing oil viscosity. (Just FYI). Effect of Break-In and Operating Conditions on Piston Ring and Cylinder Bore Wear in SI (Spark-Ignition) Engines, Schneider et al: The rate of wear is much higher within 15-20 minutes of start-up than after reaching normal operating temperature. There was a lot of data but I conclude that the initial start-up time period (first 20 minutes) result is 100 nanometers of wear whereas the steady state wear rate was only 4 nanometers per hour thereafter. (Hence we should be concerned about start-up oil thickness more than running thickness. This justifies the statement that 95 percent of engine wear occurs just after start-up). Application of a Biodegradable Lubricant in Two Flexible Fuel Vehicles, Jesper Schramm: Vegetable biodegradable oils were used showing good wear characteristics despite excessive thinning over time. (These may be next! Animal and plant oils have esters as in Red Line oils.) The SMAC, Under Pressure Oil Aeration Measurement System in Running Engines, Bregent et al: Oil aging, valve train and bearing problems and thermal problems occur with aeration. Below 110 C there is no problem but as one goes up the aeration ratio increases rapidly. (A cooler running engine from a thinner, faster flowing oil may lubricate better for this reason alone - aeration was a hot topic). Development of the Sequence IV A Valve Train Wear Lubrication Testart 1, Sagawa et al: Viscosity data reveals that the more viscous oil did not significantly alter the cam angle of minimum oil film thickness. Of greater importance is the finding that the higher viscosity oil continued to exhibit boundary layer lubrication. (Ergo thicker is not necessarily better). The effect of engine intake air humidity was significant so that tests are now done with specified humidity conditions. It was postulated that fuel dilution of oil would elevate cam wear. Fuel dilution of 4.5 percent did not effect wear. (This would have the effect of lowering the viscosity about 1 grade). The Effects of Crankcase Oil Viscosity on Engine Friction at Low Temperatures, Cockbill et al: By using lower viscosity oils there is less friction, improved cold weather starting, improved fuel economy, a savings of starting system components and less wear by increasing the rate of oil pressurization and flow in the upper oil galleries. Evaluation of Oil Performance Using the Tu High Temperature Engine Test With a View to Extending Oil Drain Intervals, Bouvier et al: Oxidation and thickening is the limiting factor for oil longevity. Generally modern oils thin only 10 percent then thicken up to 60 percent within as little as 96 hrs. of operation ( -in the accelerated test engine. Let me comment that all test criteria are designed to mimic real engine operating conditions but at an accelerated rate). There is accelerated acidification and corrosive wear that occurs. Oil thickening was also time dependent. Thickening at 30,000 km was 2 times more when done over 21 months than over a 10 month period. (Change your oil every spring as I suggested before). Development of the Sequence III G Engine Oil Certification Test, Clark et al: Engine tests were made more severe again. (Over the years the oil ratings have improved but this has always been despite the increase in testing severity. It was III ...D, E, F, and is now III G). The oil inlet temperature was decreased from 155 to 150 C. The test was 80 and is now 100 hours. There were 8 oil level adjustments allowed now there are 5. The inlet engine air temperature was raised from 27 to 35 C. The engine load was increased 25 percent. Despite all this the current 0W-20 oils were still GF-4 compliant and showed minimal wear characteristics as long as ZDP levels were higher than 0.03 percent. (The SM rated oils I have seen so far have levels of 0.08). Other papers showed how they always consider older engines when formulating new oils for full backwards compatibility. There was a lot on using thinner oils and how they do not result in excessive wear as previously feared. This is in part because of modern additives. This stuff was very, very interesting. I will reiterate that you should use the latest, highest rated oil in your car regardless of its age. By definition all oils are backward compatible. Use a grade thinner than you may at first think is best. Always use the oil with the lowest first number in the grade - use 0W-30 instead of 10W-30 and for many reasons use synthetic but mainly because of less wear and tear at start-up! aehaas More: Another question posed to me was the importance of viscosity index. I say look at the numbers not the index. The index does not tell you what thickness the oil is at various temperatures. It is actually outdated and arbitrary. A less arbitrary indication of the change in viscosity with temperature is the viscosity temperature coefficient. From: Physical and Chemical Properties of Mineral Oils That Affect Lubrication, Douglas Godfrey, William R. Herguth, Herguth Laboratories Inc., 101 Corporate Place - P.O. Box B - Vallejo, Ca. 94590-6968, 1995. Here is some comparative viscosity data form 3 years ago. Kinematic Viscosity in cSt of several Mobil 1 oils compared to the Red Line 5W-20: T(C)* 0W30 * 5W30 * 10W30 * 0W20 * RL 5W20 -20° 1994.8 2225.1 3424.8 1712.7 2995.8 -10° 872.4 944.7 1332.9 730.8 1165.3 0° 428.3 452.9 595.7 352.8 521.4 ( zero F) 10° 231.3 240.1 298.3 188.5 261.8 20° 135.3 138.3 164.1 109.5 144.5 (68 degrees F) 30° 84.6 85.5 97.6 68.3 86.3 40° 56.0 56.0 62.0 45.1 55.0 (104 degrees F) 50° 38.8 38.5 41.6 31.3 37.0 60° 28.1 27.7 29.2 22.6 26.1 70° 21.0 20.6 21.4 17.0 19.2 (158 degrees F) 80° 16.2 15.8 16.1 13.1 14.5 90° 12.8 12.4 12.5 10.4 11.3 100° 10.3 10.0 10.0 8.4 9.1 (212degrees F) cP @ 150°C HTHS 3.0 3.1 3.2 2.6 3.3 From: Lubrication, Tribology & Motorsport, R.I. Taylor Shell Global Solutions (UK), Cheshire Innovation Park, PO Box 1, Chester, CH1 3SH, UK: We discuss the effect of lubricant viscometry on piston assembly friction. For the Formula 1 engine, using the same data as for Figure 4, and assuming a top ring radius of curvature of 10 cm, Table 6 summarizes the predicted top ring friction power loss, and the predicted minimum oil film thickness, for different lubricants: Table 6: Lubricant....Power loss (Watts)....Minimum oil film thickness (Pm) SAE-20W/50........402.................0.76 SAE-15W/40........375.................0.73 SAE-10W/30........313.................0.62 SAE-0W/20..........259.................0.51 People think that a 20 wt. oil is 60 percent thinner than a 50 wt. oil, not so. It is only 30 percent thinner. aehaas Previously reported: I peeked at my neighbors manual from his Mercedes SL 65 AMG V12 biturbo with around 650 BHP?and 700 of torque. It calls for any MB 229.5 certified engine oils that include: Mobil 1 SuperSyn European Car Formula 0W-40 or Pennzoil European Formula Ultra 5W-30 or Quaker State European Formula Ultra 5W-30 oils. All 3 of these oils are specified to run at all ambient temperatures from well below freezing from Alaska to Orlando, Florida. Two of the 3 recommended oils are 30 wt. oils. Ferrari is delivered with Shell Helix Ultra 5W-30 but for the Enzo. Motor Oils - Fuel Economy vs. Wear By Blaine Ballentine, Central Petroleum Company: Viscosity and Wear Thinner oils have less drag, and therefore less friction and wear... Any abrasive particles equal to or larger than the oil film thickness will cause wear. Filters are necessary to keep contaminants small. The other side of the equation is oil film thickness. Thicker oil films can accommodate larger contaminants. Temperature has a big effect on viscosity and film thickness. As a point of reference, one SAE grade increase in viscosity is necessary to overcome the influence of a 20°F increase in engine temperature. At a given reference point, there is approximately a 20°F. difference between viscosity grades SAE 30, 40 and 50. SAE 20 is somewhat closer to 30 than the other jumps, because SAE 30 must be 30°F higher than SAE 20 to be roughly the equivalent viscosity. In other words, an SAE 20 at 190°F is about the same kinematic viscosity as an SAE 30 at 220°F, which is about the same viscosity as an SAE 40 at 240°F. This approximation works well in the 190°F to 260°F temperature range. Ford is bumping up against its CAFE requirements and recommends SAE 5W-20 oil for most of its engines in the United States. It claims SAE 5W-20 is optimal for fuel efficiency and wear. (If your engine is 20 F cooler running a thinner oil then the viscosity is the same as the next higher weight grade. Also, as wear diminishes with lesser operating temperatures then we have a benefit. Another benefit is that the thinner oil is better at startup where the majority of wear occurs.) aehaas Folks, this is it, all I have, enjoy...
Another ton of great information to digest. Thank you. I would test the quoted theory above, but we have had over 70 inches of snow here in Anchorage in the last three weeks, which is double the height of my 328, so I will take your word for it when oil change time comes.
I guess what I would like to know, is what is Ferrari running in the 550/575, or anything they are backing, or private entrants, on the track. In other words, what is recomended by Ferrari, or those racing them, for track use today as far as viscosity. Reason to ask is that many of us do at times drive our cars very hard on the street, and for that reason, I want the highest viscosity recommended. While cold weather starting is an issue with the grocery getter, my car is pretty much sheltered away until spring and generally does not see temps below 45 0r 50F. It looks like the best oil out there for hard use, according to your other thread, based solely on numbers, would be the Red Line 20/50 synthetic racing oil. The pour point was something near -40C, and flash point was above 270C, IIRC.
This will answer all your questions. Motor Oil-All Chapters: Read it ALL: http://ferrarichat.com/forum/showthread.php?t=136052 aehaas
Thanks Dr. Haas, you have completely changed my perception and past beliefs about motor oils and lubrication. Keep it coming.
Good article. After reading it over a few times and reading this thread as well I do feel I understand things a bit better. I look forward to reading more from you. I have but 2 criticisms for you. 1. In your long article you kind of neglected 5w oils and comparing 10w to 0w shows a huge difference. I think it would have been nice to add in 5w where you compared 10w and 0w. 2. In your first post of this thread ... 0°C == 32°F == freezing != 0°F
My first post in here. So Dr. Ali what you think of this oil for a 1993 Benz 190E 2.3 4 cylinders with a 260k miles? Total (Or ELF).
And the engineers at Mobil agree 100% with this statement and specifically warn against using any 0-x oil in any flat tappet motor, as used in virtually all Ferrari's...
"My first post in here. So Dr. Ali what you think of this oil for a 1993 Benz 190E 2.3 4 cylinders with a 260k miles? Total (Or ELF)." I know nothing about this oil to render an opinion. "And the engineers at Mobil agree 100% with this statement and specifically warn against using any 0-x oil in any flat tappet motor, as used in virtually all Ferrari's..." Regarding ZDDP, the API SM specification states that these oils must be backwards compatible and therefore work in all old engines. The ZDDP is reduced yet the wear and tear and general specifications are far above the original oil spec'ed for that older engine. Furthermore there are oils that exceed the SM specs that have no ZDDP at all. I do not know the new additives used but the results seem very good following used engine oil analysis. The oils I am using now are vegetable based biodegradable oils. I admire the biodegradability but use this newer oil because it seems to result in less wear and tear. Currently in use: Enzo with 0W-30 Renewable Lubricants Inc. Murcielago with 0W-20 RLI Maybach 57s with 0W-20 RLI aehaas
Hi Doc, I own a 355 F1 with 20K on her. My start up pressure was approx. 78 PSI at 68 degrees with a very thick oil of an unknown type (dealer supplied). I changed my filter and oil to Mobil 1, 0w 20. with the hopes of getting that start up PSI down a bit. It seems however that it MAY have lowered 3 PSI? Do I need to clean my pressure relief? Is this the best result I can get with this oil? Is anyone else using Mobil 1 0w 20 with a better (lower start up pressure) result? Thanks, Poor boy
if i understand Dr Haas correctly this start pressure will not be changed with using another oil as ALL oils (even a 0w20)are too thick at these temperatures and the pressure release valve will determine the systempressure.
The right way to think about this is: A) your engine wants 12-14 centiStokes of viscosity B) a 5W-20 oil has 55 centiStores of viscosity at 40dF (startup) Since 55 is greater than 14 even this thin oil is thicker that what your engine wants at startup.
For this reason we preheat oil and rotate engine for a while before starting our race cars. We also remove rear wheels, mount weights and warm up gearbox for at least 5 minutes before heading out. As an aside in endurance tune we run at very hi comprssion ratios almost 15 to one. We set up engines loosely and use a lot of oil. On the turns we pull 2.8G's so keeping oil PSI is an issue. At the end of the 24 the back of the car is coated in oil.
Synthetics don't do this anymore (any different than modern dino oils). And haven't since about 1970.
Without getting too off-track here, what sort of 'loose' tolerances are you running in your race engines? Main and rod bearing clearances etc? And are you running something like Shell's 10w-60 Helix racing stuff?
When we finish racing we'll publish everything but for the moment I can answer your second question. Yes. This weekend we're going to test the engine that finished our last 24 and see how much more HP we could get if we were air restricted less. We'll only race next year's 24 if we're allowed enough HP to have a chance to run at the top. Modern oils are really amazing and even after 24 our engine is fine.
Oh I absolutely believe it. Shell, Motul, and a couple independants really have their racing oil figured out. Flash points, HTHS, visc indexes etc. are all amazing. I *love* Brad Penn's 20w-50 esther base partial synthetic has an HTHS of 6.8. Stupidly beefy stuff. Porsche race motors and my 3.4L 308 engine absolutely love it.
