Motor Oil Midterm Examination Answer questions without looking back. This is a closed book exam. Base your answers on the information provided in these past chapters. 1- At normal operating temperature, 212 F, a straight 30 weight oil has a viscosity of how many centiStokes? A- 3 B- 6 C- 10 D- 20 E- 30 2- While racing at 95 F, mid-summer in Florida, which of these synthetic oils gives the best protection at 302 F oil temperature? A- 0W-40 B- 5W-40 C- 10W-40 D- Straight 40 weight E- They are all exactly the same 3- While starting up your car at 75 F, mid-winter in Florida, what is the approximate viscosity of a straight 10 (ten) weight motor oil? A- 3 cS B- 6 cS C- 10 cS D- 20 cS E- 30 cS or higher 4- The biggest problem with mineral based motor oils with long term use is: A- Thinning B- Thickening C- Loss of VI (viscosity index) improvers D- Both A and C E- None of the above is correct 5- Which of the following mineral based motor oils are still too thick at a 75 F startup temperature? A- 20 weight B- 10 weight C- 5 weight D- All of the above E- None are too thick
Answers to the Oil Midterm Exam I feel these were all difficult questions. You would be doing well to get 3 correct. 1- At normal operating temperature, 212 F, a straight 30 weight oil has a viscosity of how many centiStokes? A- 3 B- 6 C- 10 D- 20 E- 30 The correct answer is C- 10 cS. 2- While racing at 95 F, mid-summer in Florida, which of these synthetic oils gives the best protection at 302 F oil temperature? A- 0W-40 B- 5W-40 C- 10W-40 D- Straight 40 weight E- They are all exactly the same The correct answer is E- They are all exactly the same. 3- While starting up your car at 75 F, mid-winter in Florida, what is the approximate viscosity of a straight 10 (ten) weight motor oil? A- 3 cS B- 6 cS C- 10 cS D- 20 cS E- 30 cS or higher The correct answer is E- 30 cS or higher. 4- The biggest problem with mineral based motor oils with long tern use is: A- Thinning B- Thickening C- Loss of VI (viscosity index) improvers D- Both A and C E- None of the above is correct The correct answer is B- Thickening 5- Which of the following mineral based motor oils are still too thick at a 75 F startup temperature? A- 20 weight B- 10 weight C- 5 weight D- All of the above E- None are too thick The correct answer is D- All of the above
Question 4 is difficult. Oil, particularly mineral based oil, will thin over the first 2 to 4,000 miles but then it starts to thicken. During the "thin period" the oil is perfectly usable. Then oil thickens and continues to thicken and thicken. There is no let up. This will prevent the oil from being used any longer. aehaas
100% correct....... Thanks to your posts, Ali. I appreciate your efforts to write this info up. I've learned a great deal.
Ali, Mobil 1in 10W40 is haed to find. Can you mix equal parts of Mobil 1 10W30 and Mobil 1 15W50 to achieve someything like Mbil 1 10W40?
You could, but I think his concerns where that the oils likely have different additive packages, so mixing them may upset that balance.
