Post by
McShanks »
https://forums.nicoclub.com/mcshanks-u187047.html
Fri Sep 16, 2011 10:39 pm
Google "Bob is the oil guy." You should NOT be putting in 10W40 in this car, even in a hot Texan summer! xxW50 is RIGHT OUT of the question!!! You will wear out your engine so much faster! Your oil pressure when warmed up should be proportional to the RPM, that is at 6,000 RPM, your oil pressure should be around 60 psi, and at 1,000 RPM, about 10 psi. This ensures proper oil FLOW over and through the parts. This car should use a xxW30 weight oil. The second number is related to the viscosity at operating temp. The firs number, as the 10 in 10W30 is the viscosity at US Standard Pressure and Temperature. The lower the first number, the better. In 1990, 5W30 was not readily available, and 0W30 was unheard of. If you go synthetic, put in 0W30. This ensures oil is not too thick at startup, ensuring more oil gets to the lubed parts faster. MOST engine wear occurs at startup and warmup of the engine, before the oil has heated and "thinned" enough to provide the proper lubrication layer.
Personally, I plan on using AutoRX additive once I get all the other little issues sorted out. There are many options, and many opinions, and many various results out there for all the products you can find. Pick one and go with it, follow the directions, and make sure you put in GOOD oil once you are done with your treatment. DO NOT put additives in Synthetic oils. I currently use 5W30 Valvoline, and once I do my oil treatment, plan an switching to 0W30 Synthetic, not sure of the brand, yet.
Read some of the stuff on bobistheoilguy.com. It is very enlightening, and makes alot of sense once you are given the knowledge. Ultimately, each engine and oil pump is a little different from the next one, so it is best to drop down a weight at a time until you are getting the proper proportion of oil pressure to RPM. If you have 10W30 in your car, putting in 5W30 or 0W30 is fine, as this will not change the operating conditions with a warm engine AT ALL compared to 10-, 15-, or 20-W30 oil. But the oil viscosity will be much closure at COLD temperatures to the proper viscosity of WARM temperatures. If you have xxW40, and your oil pressure is higher than what it should be, drop it down to xxW30.
Due to the increasing quality and performance of oil in the last 10-20 years, modern cars are calling for 5W30 or even 0W30 oils, and some car companies have even revised their manuals for older cars recommending 5W30 (or 5W40 or whatever second number weight required) oil instead of the 10W30 or 15W30 oils. Check it out for yourself, and test this at your next OCI.