# conventional oil just fine



## dre (Aug 16, 2004)

Ive read alot about the claimed advantages of synthetic oil, but here is my
experience for what its worth. I put 230,000 miles on a 82 Nissan maxima and
the car never gave me any trouble or burned any oil. I used Castrol conventional
oil in this car as well as a 94 Nissan sentra which I gave to my son with 250,000
miles on it .The sentra engine has never been apart and still doesnt use oil or smoke. I commute 600 miles a week to work and changed the oil at about 8,000 mile intervals. I read about people with 50,000 miles on their engine and
how well snthetic has protected them. I am convinced that alot of oil advertising is just hype and the main reason Nissans engines last is due to ther
superior design and not the brand of oil used.


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## JCSC2 (Jun 13, 2004)

I agree, I have seen many many high mileage vehicles. None of them used synthetic. I believe syn is probably better but have had good luck with standard oil. If you check it and change it you shouldn't have a problem racking up the miles. Just my opinion


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## chimmike (Oct 17, 2002)

synthetic is proven better, but nothing says conventional oil is bad.


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## BII (May 13, 2004)

synthetic = lower operating temps & better vescosity

however, on stock motors that are not pushed hard the difference to reliablility and longevity is usually not significant enough in most owner's eyes to merit the added expense.


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## Tavel (Aug 21, 2004)

On a normal commuter type car, conventional oil is fine. synthetic is more stable has better cleaning capabilities, but these differences will certainly not be realized on a commuter car. 

the only time i use synthetic is for the first oil change of a new car...i think it cleans out the engine a little better than normal oil. but this is only because i have to assume that the vehicle has missed the last oil change(and most likely more, people dont take car of cars.) but after that first oil change i use supertech(walmart generic) non-synthetic.


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## Bror Jace (Apr 26, 2003)

*dre*, you are right that there’s a lot of goofy hype out there about synthetic oils ... even more than a decade ago. The problem is that many "synthetics" are no longer _really_ "synthetic." Most are made from a highly refined, Group III mineral base stock and some top quality mineral/conventional oils like Schaeffer, Pennzoil Pure Base and Chevron Supreme are made from a nearly-as-good Group II+ mineral base ... and retail for a third or even a quarter the price. 

The only true synthetics (Group IV PAO and/or Group V ester) I know of are Mobil 1, Red Line, Schaeffer, NEO, Torco, Motul, Royal Purple (racing grades only) and Amsoil (again, depending on grade).

After seeing many laboratory UOAs (Used Oil Analyses) I agree that for the first 3,000 or even 4,000 miles, good conventional oils can guard against wear just as good as synthetics, even the "true" synthetics. During this phase, the additive package has more to do with preventing wear than the base oil. I like a potent barrier additive package with 100-200 PPM (parts-per-million) of molybdenum (and boron, too, if I can get it).

After the 4,000-5,000 mile mark, however, you are neglecting/abusing your motor by leaving the same mass-market 5W-30 in your sump. testing shows that in most applications, the additive package (TBN and barrier anti-wear adds) is depleted and the rate of wear will begin to accelerate from this point forward. The detergents and dispersants have also been pushed past their limits and the old oil will begin to leave a layer of deposits inside the motor. Of course, some engines will put up with a lot more neglect/abuse than others.  

Synthetics really come into their own in the extremes of temperature (both hot and cold) where they flow better and resist oxidation. And, you can go longer between changes if you really want to because they resist oxidation (which thickens oil up).

Many claim that synthetics run cleaner and leave fewer deposits. This is _probably_ true (for a number of reasons) but a good mineral oil with a proper additive package will run just as cleanly in most applications as long as the interval isn’t pushed too long.

And if you want internal cleanliness, the HDEOs (Heavy Duty Engine Oils) meant for gas as well as diesel engines are hard to beat … and less than $2 per quart.

If you do a search on the word "synthetic" you'll find lots of threads on the subject of oils. The one below is pretty good (but long) and was originally in one of the Sentra sections but I believe was moved to this "general" section: 

http://www.nissanforums.com/showthread.php?t=19361&highlight=synthetic

So, what oil do I use in my QR25DE? Schaeffer Supreme 7000 synthetic blend, and I change it every 5,000 miles or so. I recently posted my latest UOA of this oil which was very, very good. 

*Tavel*: _ “The only time I use synthetic is for the first oil change in a new car ... I think it cleans out the engine a little better than normal oil. But this is only because I have to assume that the vehicle has missed the last oil change(and most likely more, people don’t take car of cars) but after that first oil change I use Supertech (Walmart generic) non-synthetic."_

I think your reasoning is pretty good, but I think you're better off running a gas/diesel HDMO (mostly 15W-40) for two, short-duration oil changes in a row ... maybe 1,500 – 2,000 miles each. Use a cheap filter and swap that out each time, too. Better cleaning effect, less money. 

Oh, and Supertech oil has a pretty decent additive package. Better than some major brands such as Valvoline All-Climate.


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