No synthetic oil in Cadillac

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Hi all! My grandfather has a 2002 Cadillac Deville with 53,500 Mi on it. Ever since he bought it new I have changed the oil&filter in it for him. He always buys the oil, but its just regular 10w-30, not synthetic. I have told him over and over that the synthetic oil would be better for it, and probally make it last longer. Since he's old (79) and very old-fashioned, he says that synthetic oil is "the worst oil you can use. It's not even real oil." So, I guess it will have regular 10w-30 oil, and an AC-Delco filter in it for life. We change it every 3,500 Mi or so, and I was just wondering if it will really matter to the life of the engine in the long run. Thanks, Talker
 
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It's probably on it's last legs now with 3,500 mile oil changes with conventional oil. Get real. It's going to last just as long as if you ran synthetic IMO. We've proven time and time again that modern conventional oil is fine. Baring a catastrophic failure like a head gasket or a major overheat (in which case, no oil will stop the carnage), it'll go as long as you put the money into the OTHER thinsg that usually send cars to the scrapyard - rust, transmission problems, collisions, all the nickel and dime things like suspension parts, brakes, electrical gremlins, A/C that stops working, gummed up radiator etc. etc. etc. Given good maintenance, which 3.5K oil change intervals are, oil alone is usually the last thing that stops a vehicle in it's tracks. I say let grampa alone. He knows best! You're going to be putting money in most other parts of the car as it gets up past 150,000 miles.
 
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 Originally Posted By: digitalSniperX1
Just make sure you don't use Pennzoil YB in it cause it's got wax in it ;\)
^now thats old school thinking^ Don't Cadillacs come with a Mobil 1 fill from factory? I'd assume the owners manual would tell you if it requires Full Syn? If it does show gramps, maybe you'll change his mind? The Northstar V8 is a nice engine, but I wouldnt say it is elite. It probably falls under StevieC's theory of 99% of cars will last for ever with reasonable OCIs with dino...
 
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talker

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True.... very true let me ask another question. It burns about 1 and a half quarts of oil in between oil changes. Wouldn't a synthetic oil help it
 
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gramps isnt the first old person to be stuck in ways haha...i think it is a high performance engine and GM recomends synthetic..you should take it out on hiway and open it up, they say a engine like that needs it...glad he bought a american car from MICH
 
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http://townhall-talk.edmunds.com/direct/view/.f1078f6/20 Apparently the oil consumption is a known problem with these engines, and many folks report higher consumption with synthetic oil. Maybe your grandpa isn't that dumb after all when it comes to his car and what oil to use. I'd keep on doing what you're doing, but sneak the ol boat out once in a while and open her up on the highway!
 
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It needs to be given a load every once in a while to make sure everything's still seated properly. Take it out for a drive, get the oil nice and hot, then WOT up a few long on-ramps. Regular oil probably won't hurt it as long as you change it regularly.
 
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I don't think you could prove that syn oil will make an engine last longer in all applications. That engine with your maintenance schedule will allow the engine to last as long as it is going to last.
 
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 Originally Posted By: digitalSniperX1
Just make sure you don't use Pennzoil YB in it cause it's got wax in it ;\)
Shell ultra helix is made from wax. Is wax only good for F1 and GP cars, skis and surfboards?
 
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 Originally Posted By: ARCOgraphite
 Originally Posted By: digitalSniperX1
Just make sure you don't use Pennzoil YB in it cause it's got wax in it ;\)
Shell ultra helix is made from wax. Is wax only good for F1 and GP cars, skis and surfboards?
I can't believe I'm defending fingertipshooter, but I'm sure he's was being sarcastic.
 
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3500 mile OCIs on conventional? He doesn't need synthetic. The only benefit he would get from syn is if he were to double that oil change interval.
 
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 Originally Posted By: Drew99GT
http://townhall-talk.edmunds.com/direct/view/.f1078f6/20 Apparently the oil consumption is a known problem with these engines, and many folks report higher consumption with synthetic oil. Maybe your grandpa isn't that dumb after all when it comes to his car and what oil to use. I'd keep on doing what you're doing, but sneak the ol boat out once in a while and open her up on the highway!
This is true. GM used some type of experimental hone cut, for whatever reason, that's GM for you... and thus the crosshatch retains more oil than usual. I'm sure that special hone technique doesnt help with rings wearing in either. I wouldnt waste time with synthetic in that engine, so for all the wrong reasons, your gramps is essentially doing the right thing. So +1 for conventional petrojuice with your gramp's religious and unnessecarily frequent oil change schedule is fine.
 

KW

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Years ago when synthetic oil first became popular it caused all kinds of problems. It caused camshaft failure and leaked out the front cover and rear main like it was supposed to or something. Some old timers got bitten by it and cost them a lot of money. That's not a problem now a days at all. But the first stuff was not meant for an engine internal combustion.
 
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