Have had some really great responses to my request for oil preferences. The theme so far, and we need more responses, is that Castrol/Valvoline is the best non synthetic and that Red Line/Mobil 1 is the best synthetic. But it raises a question in my mind and perhaps the experts can answer it. "I always understood that the lubricity of the conventional oil is the same as the synthetic. The reason for changing conventional oil so frequently is that the additives break down. The oil can be "reclaimed" by re-refining to remove impurities and replacing the additives." So, that generates a couple of questions, assuming my assumptions are correct. 1. Does synthetic oil have additives and if so, why don't they break down? 2. If, as some have suggested, you can prolong oil changes with synthetics, why do new car manufacturers threaten that you void warranty unless you change oil - conventional or synthetic at the recommeded intervals. I believe even the synthetic folk recommend sticking to the 6,000 mile recipe. So, some would reason, in a conventional vehicle that is not raced, why spend 4 times the money for the same results? Ron
Ron. I'm not sure the lubricity is the same. Synthetics I have been told are "slipperier" and tend to remain slippery at high temps. I hope others will ratify that or correct that belief. Dan ronald.robertson@sympatico.ca wrote: > Have had some really great responses to my request for oil > preferences. The theme so far, and we need more responses, is that > Castrol/Valvoline is the best non synthetic and that Red Line/Mobil 1 > is the best synthetic. But it raises a question in my mind and perhaps > the experts can answer it. > "I always understood that the lubricity of the conventional oil is the > same as the synthetic. The reason for changing conventional oil so > frequently is that the additives break down. The oil can be > "reclaimed" by re-refining to remove impurities and replacing the > additives." > So, that generates a couple of questions, assuming my assumptions are > correct. > 1. Does synthetic oil have additives and if so, why don't they break down? > 2. If, as some have suggested, you can prolong oil changes with > synthetics, why do new car manufacturers threaten that you void > warranty unless you change oil - conventional or synthetic at the > recommeded intervals. I believe even the synthetic folk recommend > sticking to the 6,000 mile recipe. > So, some would reason, in a conventional vehicle that is not raced, > why spend 4 times the money for the same results? > Ron
Synthetics have no additives like conventional oil. They are manufactured in end form. Conventional oil has the base stock with VI additives and a host of others to make it work in different applications. In fact, cars that specify synthetics from the factory are now showing extended drain intervals. Case in point, our new S4 Audi holds 12 qts. of synthetic oil. I took it to the dealer and wanted an oil change at 3k miles. He said Audi wants the oil in for a minimum of 5k and recommends 9k in the book! Something about the oil not being in "the zone" until it has some miles on it. New GM cars also have oil life monitors that are quite sophisticated and dictate oil changes in the 6-7k range, in my experience. Why spend the extra money? Cheap insurance! Synthetic oils are far superior. Plus, most pick up an MPG or two, and your car lasts longer. Even at 3k intervals I think it is a wise investment. Castrol GTX is $2.19/qt. here. Mobil 1 is $3.50 ,less on sale or in the gallon jugs. SO, $6-7.00 more per change, divide that by 3,000 miles and...cheap insurance. Colin ----- Original Message ----- From: Ronald Robertson To: Shelby Mustang Sent: Saturday, March 12, 2005 7:48 AM Subject: Oil survey Have had some really great responses to my request for oil preferences. The theme so far, and we need more responses, is that Castrol/Valvoline is the best non synthetic and that Red Line/Mobil 1 is the best synthetic. But it raises a question in my mind and perhaps the experts can answer it. "I always understood that the lubricity of the conventional oil is the same as the synthetic. The reason for changing conventional oil so frequently is that the additives break down. The oil can be "reclaimed" by re-refining to remove impurities and replacing the additives." So, that generates a couple of questions, assuming my assumptions are correct. 1. Does synthetic oil have additives and if so, why don't they break down? 2. If, as some have suggested, you can prolong oil changes with synthetics, why do new car manufacturers threaten that you void warranty unless you change oil - conventional or synthetic at the recommeded intervals. I believe even the synthetic folk recommend sticking to the 6,000 mile recipe. So, some would reason, in a conventional vehicle that is not raced, why spend 4 times the money for the same results? Ron
Ron and all- As for oil change intervals, Take this under consideration: I have a 2002 e46 M3. It uses 10W60 Castrol TWS syn. oil. BMW uses an on-board computer to determine service intervals depending on duty cycle, temp., drive-time, etc. Basically, it boils down to approx. 15,000 mi. between changes. I change half-way between that, just to be on the safe side (7 ltrs.@ $8.00/ltr.!) but the point is that BMW believes that the oil will take it even in a ultra-high performance engine w/an 8k redline and stands behind it 100% even at that extended interval. My wife drives a 2003 Mini Cooper S and it's the same story with the same interval and they list Mobil 1 5W30 as an approved oil. (We still change 1/2 way between or at 7,500 mi.) The Shelbys and our F250 SD V-10 get fed Motorcraft 10W-30. The truck gets changed every 3,000 mi. (short stop-and-go and car trailer towing). The Shelbys get an annual change since they don't go too far from the "stable". Incidentally, I have heard that Mobil supplies Motorcraft w/its conventional oil (unsubstantiated). Regards, Stan ----- Original Message ----- From: Ronald Robertson To: Shelby Mustang Sent: Saturday, March 12, 2005 8:48 AM Subject: Oil survey Have had some really great responses to my request for oil preferences. The theme so far, and we need more responses, is that Castrol/Valvoline is the best non synthetic and that Red Line/Mobil 1 is the best synthetic. But it raises a question in my mind and perhaps the experts can answer it. "I always understood that the lubricity of the conventional oil is the same as the synthetic. The reason for changing conventional oil so frequently is that the additives break down. The oil can be "reclaimed" by re-refining to remove impurities and replacing the additives." So, that generates a couple of questions, assuming my assumptions are correct. 1. Does synthetic oil have additives and if so, why don't they break down? 2. If, as some have suggested, you can prolong oil changes with synthetics, why do new car manufacturers threaten that you void warranty unless you change oil - conventional or synthetic at the recommeded intervals. I believe even the synthetic folk recommend sticking to the 6,000 mile recipe. So, some would reason, in a conventional vehicle that is not raced, why spend 4 times the money for the same results? Ron
Ron and all- Just remembered a company that some of you may be interested in contacting: Blackstone Labs. www.blackstone-labs.com . These folks will send you small containers for an oil sample. You follow the directions and send it back to them. In a matter of a couple of days, they will e-mail you back a full, detailed report on your oil and the condition of the engine and whether the engine is healthy or sick and, if so, where the problem/s may be. Great for peace of mind. Check 'em out. Regards, Stan ----- Original Message ----- From: Ronald Robertson To: Shelby Mustang Sent: Saturday, March 12, 2005 8:48 AM Subject: Oil survey Have had some really great responses to my request for oil preferences. The theme so far, and we need more responses, is that Castrol/Valvoline is the best non synthetic and that Red Line/Mobil 1 is the best synthetic. But it raises a question in my mind and perhaps the experts can answer it. "I always understood that the lubricity of the conventional oil is the same as the synthetic. The reason for changing conventional oil so frequently is that the additives break down. The oil can be "reclaimed" by re-refining to remove impurities and replacing the additives." So, that generates a couple of questions, assuming my assumptions are correct. 1. Does synthetic oil have additives and if so, why don't they break down? 2. If, as some have suggested, you can prolong oil changes with synthetics, why do new car manufacturers threaten that you void warranty unless you change oil - conventional or synthetic at the recommeded intervals. I believe even the synthetic folk recommend sticking to the 6,000 mile recipe. So, some would reason, in a conventional vehicle that is not raced, why spend 4 times the money for the same results? Ron
