Douglas17313 Posted March 24, 2017 Share Posted March 24, 2017 I just bought a 1986/7 Gulfstream Conquest with about 37K actual miles. This weekend my area is expected to have warm weather and I want to change the oil. In all my cars I use synthetic. I would like to do the same with the Toyota as well, however I'm not sure of the effect this will have on the engine. Should I use conventional or synthetic? I do not have the service records so I don't know it's history. Thanks in advance for any advice. Quote Link to comment Share on other sites More sharing options...
fred heath Posted March 24, 2017 Share Posted March 24, 2017 You can use synthetic with no problem. Members here are kinda split on its benefits. I use it in the engine,transmission and rear differential. I will never go back to regular motor oil. FWIW. Fred. Quote Link to comment Share on other sites More sharing options...
Douglas17313 Posted March 24, 2017 Author Share Posted March 24, 2017 Thank you for your response. I've used synthetic so long that I hate to go backwards. I have been getting conflicting info about a 30 year old engine going specifically to synthetic. Quote Link to comment Share on other sites More sharing options...
Derek up North Posted March 24, 2017 Share Posted March 24, 2017 I have heard reports of leaks starting after switching to synthetic and then disappearing again after switching back to dino oil. But I have no experience with synthetic oil. Quote Link to comment Share on other sites More sharing options...
fred heath Posted March 24, 2017 Share Posted March 24, 2017 17 minutes ago, Douglas17313 said: Thank you for your response. I've used synthetic so long that I hate to go backwards. I have been getting conflicting info about a 30 year old engine going specifically to synthetic. My engine is 38 years old. No leaks due to upgrading to synthetic. I did a 900 mile road trip stopping only for gas and occasional rest. Motor and drive train functioned flawlessly. Oil pressure and coolant temp were well within factory specs. Quote Link to comment Share on other sites More sharing options...
vrocrider Posted March 24, 2017 Share Posted March 24, 2017 (edited) My understanding along with some experience with synthetics is as follows: 1. Synthetic's great cleaning properties can result in oil leaks in high mileage dirty engines as the oil cleans deposits off seals, gaskets, etc. exposing leak pathways previously hidden by gunk. 2. Synthetic is a lighter weight oil as compared to equivalent dino oil which can result in oil consumption in older engines with build tolerances greater than today's engines. I have personally experienced this issue. I went to semisynthetic in this engine & solved oil consumption problem. I recently purchased an oil friction reduction additive product called Ceratec made by LiquiMoly in Germany. I put it in a 2012 Ford Explorer with 110K miles that sits a lot between drives. After installing this product I could immediately tell the engine has a higher spinning pitch sound indicating less friction when cranking after having sat for several days. I was very very surprised. The stuff is not cheap at $22plus dollars for one 300ML bottle off ebay. Also heard good things about BG MOA but it's more pricey. Edited March 24, 2017 by vrocrider Quote Link to comment Share on other sites More sharing options...
Maineah Posted March 24, 2017 Share Posted March 24, 2017 It once was an issue but no longer appears to be it should not cause leaks. It is up to you if you use syn oil your engine will probably last 150K mile and then some if you use regular oil it probably will last 150K also. If you don't care about cost go for it but trust me engines have no "feelings". Quote Link to comment Share on other sites More sharing options...
vrocrider Posted March 25, 2017 Share Posted March 25, 2017 9 minutes ago, Maineah said: It once was an issue but no longer appears to be it should not cause leaks. It is up to you if you use syn oil your engine will probably last 150K mile and then some if you use regular oil it probably will last 150K also. If you don't care about cost go for it but trust me engines have no "feelings". I've got a 94 Jeep Cherokee with inline 6 cylinder with 260K miles with mostly Walmart Brand dino 10w-30. Engine has never been apart & runs great. Got a good deal on some synthetic & this is where I found increased oil consumption. Went back to dino or semi S when price is good. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted March 25, 2017 Share Posted March 25, 2017 Over the years reading about the pro's and con's of synthetics I could see no reason not to use them. I could also not find any reason for me to use them. As far as additives if I want my vehicle to run smoother, increase MPG and have better performance, I wash it. Now there are some rumors floating around that not oil sold as synthetic is really synthetic, that only cetain brands are "true synthetics". I am not going to pursue it as I am not going to use it anyway. Quote Link to comment Share on other sites More sharing options...
Derek up North Posted March 25, 2017 Share Posted March 25, 2017 Well, as far as I'm concerned, they're all 'synthetic' since I don't think any brand is pumped straight out of the ground and straight into my engine! Quote Link to comment Share on other sites More sharing options...
hunkaman Posted March 25, 2017 Share Posted March 25, 2017 TO MY KNOWLEDGE (NOT AN EXPERT) ENGINE OIL DOES NOT BREAK DOWN, BUT THE ADDITIVES DO. THE IMPORTANT THING IS THE OIL AND FILTER BEING CHANGED ROUTINELY. I HAVE NO PROBLEM WITH USING NON SYNTHETIC IN A 25 TO THIRTY YEAR OLD ENGINE, NOR DO I HAVE A PROBLEM WITH USING SYNTHETIC OR SEMI SYNTHETIC EXCEPT FOR THE COST FACTOR. THERE MAY BE SOME PERFORMANCE OR PROTECTION FACTORS INVOLVED WITH THE SYNTHETIC OILS, BUT I HAVE HAD VEHICLES GO 200 K PLUS MILES WITH NON SYNTHETIC OILS. JOE FROM DOVER. Quote Link to comment Share on other sites More sharing options...
Maineah Posted March 25, 2017 Share Posted March 25, 2017 15 hours ago, jjrbus said: Over the years reading about the pro's and con's of synthetics I could see no reason not to use them. I could also not find any reason for me to use them. As far as additives if I want my vehicle to run smoother, increase MPG and have better performance, I wash it. Now there are some rumors floating around that not oil sold as synthetic is really synthetic, that only cetain brands are "true synthetics". I am not going to pursue it as I am not going to use it anyway. The US is the only country that allows blended synthetics to be called " full synthetic" Oil does not "ware out" it becomes contaminated with water,gasoline and combustion by-products so does syn. blend oil. I usually don't sell any thing until it has at least 250K I have yet to lose an engine. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted March 25, 2017 Share Posted March 25, 2017 An oil change on a Diesel electric locomotive is likely about $5000 now. Try to convince them to change oil every 3000 miles The oil is monitored and treated and only changed when contamination occurs. Even then the oil is not thrown out it is recycled as it is still good oil. Quote Link to comment Share on other sites More sharing options...
markwilliam1 Posted March 25, 2017 Share Posted March 25, 2017 I'm a fan of synthetics. My Toyota Prius uses synthetic oil and the service interval for a oil change is 10,000 miles. They use synthetics for a reason I assume. Quote Link to comment Share on other sites More sharing options...
Lee & Joan Posted March 31, 2017 Share Posted March 31, 2017 My Transmission guy told me not to put synthetic into my older original transmission as it would cause problems. Something about the old materials in the original 30 year old tranny. I have since had it rebuilt (with modern materials), and started out with full synthetic. At same time I got the biggest trans cooler that could be jammed in front of the radiator I could find. I seem to get the best miles per quart of engine oil with 20/50 Castrol. I usually run 4 quarts of that with one quart of full synthetic Castrol, Amsoil, or Mobile, 20/50 if I can find it. Going to a 10/40 seems to up oil consumption a lot. I also run a Purolator PL 30001 oil filter as it holds an extra 1/2 quart of oil in a bigger filter that screws right in the same threads. Other filter brands often are numbered 30001, it is a real common filter but about twice the size of Toyotas. Pure synthetic 20/50 has saved one of my old Honda XR200 air cooled motorcycles more than once when I came home and put a 0.9 quarts into the 1 quart crankcase after a long 250 mile trail ride. Never would have done that with straight Dino oil. Both mineral oil and synthetics have their pluses and minuses so I really like a blend, but I like to make my own starting with high quality "pure" synthetic and mineral bases. These 22R engines are working as hard as they can to pull these houses around and I like to give them the best oil I can afford and change it and the filter often. Quote Link to comment Share on other sites More sharing options...
Maineah Posted March 31, 2017 Share Posted March 31, 2017 On 3/25/2017 at 11:52 AM, jjrbus said: An oil change on a Diesel electric locomotive is likely about $5000 now. Try to convince them to change oil every 3000 miles The oil is monitored and treated and only changed when contamination occurs. Even then the oil is not thrown out it is recycled as it is still good oil. One of my duties was to look after our "little" generator it was a 16 cylinder 2200 HP Cat. It held 150 gallons of oil. Needless to say it was only changed when an oil analysis came up with bad juju it makes one think about an oil change when an engine takes 3 barrels of oil. We by the way did not use synthetic oil. I wouldn’t mind synthetic oil hype if it really was synthetic, in this country there is only 3 co. that have real syn oil and Mobil is not one of them, Amsoil was but not anymore. Quote Link to comment Share on other sites More sharing options...
Maineah Posted March 31, 2017 Share Posted March 31, 2017 My Transmission guy told me not to put synthetic into my older original transmission as it would cause problems. Something about the old materials in the original 30 year old tranny. I have since had it rebuilt (with modern materials), and started out with full synthetic. At same time I got the biggest trans cooler that could be jammed in front of the radiator I could find. I disagree with using syn trans oil in an old transmission but I agree with changing any trans fluid with high miles on it may do damage. Syn. trany fluid does do better with high heat and with any thing that tows or has excessive weight heat is an issue. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted March 31, 2017 Share Posted March 31, 2017 43 minutes ago, Maineah said: One of my duties was to look after our "little" generator it was a 16 cylinder 2200 HP Cat. It held 150 gallons of oil. Needless to say it was only changed when an oil analysis came up with bad juju it makes one think about an oil change when an engine takes 3 barrels of oil. We by the way did not use synthetic oil. I wouldn’t mind synthetic oil hype if it really was synthetic, in this country there is only 3 co. that have real syn oil and Mobil is not one of them, Amsoil was but not anymore. Hard to change the oil every 3000 miles when it does not move : ) Quote Link to comment Share on other sites More sharing options...
Lee & Joan Posted March 31, 2017 Share Posted March 31, 2017 Maineah said " in this country there is only 3 co. that have real syn oil and Mobil is not one of them, Amsoil was but not anymore." So who are the 3 companies that still make pure syn oil? I have been using Bel Ray & Castrol in my bikes, are they real synthetics? Quote Link to comment Share on other sites More sharing options...
markwilliam1 Posted March 31, 2017 Share Posted March 31, 2017 Always thought Mobile 1 was pure synthetic. Wasn't it the first to come out years ago? It's the only synthetic I have ever used and I use it in Everything! Quote Link to comment Share on other sites More sharing options...
Maineah Posted April 1, 2017 Share Posted April 1, 2017 16 hours ago, markwilliam1 said: Always thought Mobile 1 was pure synthetic. Wasn't it the first to come out years ago? It's the only synthetic I have ever used and I use it in Everything! Have a real good look at the jug it is a blend. Quote Link to comment Share on other sites More sharing options...
Maineah Posted April 1, 2017 Share Posted April 1, 2017 21 hours ago, jjrbus said: Hard to change the oil every 3000 miles when it does not move : ) Pumps. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted April 1, 2017 Share Posted April 1, 2017 On 3/31/2017 at 3:37 PM, markwilliam1 said: Always thought Mobile 1 was pure synthetic. Wasn't it the first to come out years ago? It's the only synthetic I have ever used and I use it in Everything! I think it was when it first came out. I don't recall a big advertising campaign by Mobile when it changed to a blend. You know millions of $$$$$ spent to introduce the change to the public. There are some rumors that they are responsible for lobbying to have the criteria changed for the meaning of synthetic. I can't imagine that a large corporation would do something like that in the US? Quote Link to comment Share on other sites More sharing options...
markwilliam1 Posted April 1, 2017 Share Posted April 1, 2017 Not in the good old USA....no way:-) Quote Link to comment Share on other sites More sharing options...
DanAatTheCape Posted April 2, 2017 Share Posted April 2, 2017 I use Castrol 10w30 conventional. Quote Link to comment Share on other sites More sharing options...
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