do not use synthetic oil

If your engine is running too ricch, the extra fuel can wash the oil off of the cylinder walls and end up in the oil pan. This will contaminate and THIN OUT the oil.

65fastback2+2 said:

internet, not just bulletin boards thank you, which happens to be the same place you most likely get your info. and still, i was letting everyone know that my car didnt like the stuff at all, whats the harm in that?

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Actually, I used to work for Mobil distributership and had access to their engineers in analyzing oil related component failures. So no, I don't get my info from the same place as you.

The reason I even responded (and "the harm in that") is because you told everybody who was reading to never use synthetic oil, period, based in a case study of one. That is an incredibly ignorant statement, uttered by someone who clearly has very little knowledge of the subject.

one more

i have a 96 Cobra with 170,000 miles. still runs great... daily driver .... 320miles on 13.4gallons. i change the oil (mobil 1 Syn) every 3k-4.5k miles. only brand of oil that has ever been used. i wish the previous owner of my excursion had used mbile 1 syn in the 5.4.... but oh well .... when i rebuild and break in ill use mobil 1... hmm maybe ill go with navi 32V ... oh sorry rambling...

Mobil 1 - says it all.

HistoricMustang
www.historicmustang.com

65fastback2+2 said:

i was just mainly ticked off at the oil personally

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Well, you dont even need to use it. If it doesnt work for you, just use petroleum.

I use redline 10W 30 on my 331.

500 break in miles with regular oil and then synthetic.

I just like the $80 oil changes.

Max Power said:

Actually, I used to work for Mobil distributership and had access to their engineers in analyzing oil related component failures. So no, I don't get my info from the same place as you.

The reason I even responded (and "the harm in that") is because you told everybody who was reading to never use synthetic oil, period, based in a case study of one. That is an incredibly ignorant statement, uttered by someone who clearly has very little knowledge of the subject.

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Hey Max,
I have a couple questions about synthetics. Looks like you might have the tech.

I've always felt uncomfortable about the reasoning behind extending the oil change intervals when using synthetics. I've always assumed that oil changes are for getting rid of the "dirt" particles that end up in any engine. Do synthetics somehow not keep the dirt in suspension?

I never run my Mustang enough for the oil to look dirty - I change two or three times a year, but I probably don't even get 3,000 miles on the car in a year. So why are oil change intervals often stated as 3 months or 3,000 miles?

What happens to an oil in 3 months that's so different between dino and synthetics? I always thought synthetics were exactly the same as dino, except that the molecules are more uniform in length. Dino by nature will have more random molecular lengths, since it comes from crude oil. Or is synthetic just refined to a more accurate fractional weight?

Will synthetic oil actually make an engine last longer? How much longer?

Thanks!

You get less wear with synths, therefore less particles in the oil TO wear the engine. I believe the synth oil doesn't break down as easily or as fast as dino stuff too. Of course if you changed it like dino oil you'd have even better wear protection, however, that may be overcome by all the dry starts after you change the oil.

brianj5600 said:

Uh, 10w30 will be thinner than 10w40 no matter what brand, chemistry, or what ever.

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I agree. You can't compare different types of oil if you don't use the same weight of oil. It makes no sense at all.

ive always used mobil 1 in all my mustangs, even the v6 ones! my new 65 engine only has 25 miles on it, i cant wait for it to break in that way i can start using the good stuff... all my other cars, i use a ford syn blend... its the same price as regualr oil, cant beat that! but you guys are right, ill trust the auto manufacturers who require it in hipo engines against 1 bad experience! dont really wanna throw this out there, but many hi perf. cars require it, dare i say even the corvette

Mobil 1 and Royal Purple 20w-50 synt. are the gods of oil

I've used Mobil-1 in all of my cars for 18 years, I swear by it. But...I'll say that Amsoil and Royal Purple are even better, no doubt in my mind about that. So while I'd say both of them are in a better class, they cost twice as much as Mobil-1 but they are not twice as good...LOL.

65fastback2+2 said:

A)
B)i read more

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The only negative post I see on this link, other than it causing leaks in previously dino oiled cars with lots of miles, is the one you posted at the end.

I ran Castrol Synthetic oil in my '92 GT, after the first oil change, I would perform a filter change at 3,500 miles and a filter and oil change at 7,000 miles. The used synthetic oil "felt" the same as the new did that I was putting in it, it was just dirtier. When I change dino oil at 3,000, it "feels" different than the new dino oil going in. Thinner would be the closest description I guess.

Route666 said:

You get less wear with synths, therefore less particles in the oil TO wear the engine. I believe the synth oil doesn't break down as easily or as fast as dino stuff too. Of course if you changed it like dino oil you'd have even better wear protection, however, that may be overcome by all the dry starts after you change the oil.

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Its wont make a huge difference if you're getting combustion byproducts past the rings or valves, though. You'll still have to change it as frequently as forced to by the speed of the contaminant buildup. You could also argue that the synthetic will slow the wearing of those parts which in turn slow the oil contamination.

I'm with 65fastback on this, though. If the synthetic costs twice as much and does not make my engine last twice as long, then its just wasting my money.

Here's something else to consider: I frequent ThumperTalk, a 4-stroke dirtbike site and the dino vs. synth debate is always coming up. There are a few people who have had oil analyses done after running both high-grade synthetics and high-grade petroleum oils. This is after being run through an aircooled 600cc engine that shares its oil with the gearbox. High heat, load, and lots of shear. The funny thing is the analyses keep coming back the same for both.

65fastback2+2 said:

Im 19, what more do you want than for me to speak from my experience?

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Maybe you shouldn't make recomendations then. Just a thought. Don't wanna be harsh, because you appear to know a lot more than most 19 year olds, but there are a lot of people here with a vast archive of knowledge. You should be asking questions, rather than telling others what to do.

Hack, synthetics have a number of benefits. First, they are far more slippery. Anyone who has tried to use a full synthetic oil in a bike with a wet clutch can tell you that. Because they are so slippery, your engine offers less friction or resistance to turning, yielding more horsepower and better fuel economy. It varies by engine design, but all engines can benefit.

The other benefit is that it doesn't break down under somewhat harsh conditions, like high heat, dirt contamination and age. If you have dirt particles of any size floating around, you have other problems, but the stuff that can get through a good filter is pretty harmless. Because of the durability, you can run them for extended periods of time, helping to off set the higher price of the oil. You can easily run full synthetics 10,000-15,000 with no worries, if you change the filter every 5,000 or so, depending on your driving conditions. I do it all the time, and have on many vehicles.

There are some downsides too. Because the oil is so thin, it does a much better job of escaping. Older cars with looser tolerances will leak more with it, and cars that burn a little oil will burn more with a thinner synthetic.

The other downside is cost. If you change your oil every 3,000 while running full synthetic oil, you are pouring money down the drain. The peace of mind is worth it to some, especially those who don't put a lot of miles on their baby, but it's not necessary. People who recommend changing full synths every 3,000 miles are just trying to sell you more oil.

When Mobil 1 first came out in the late seventies, they recomended that people run it 25,000 miles, changing the filter every 5,000. We had some problems with the early Mobil 1 oil changes. Most American cars in the seventies would leak the stuff. People hated that. They also didn't feel like it was any convenience, since they had to change the filter at 5k anyway. But I never saw any engine wear or failure on any of those cars, even when they ran it that long. Also, up here in the northland, a fair amount of fuel gets into the oil, and while a full synth will handle that far better than dino, 25k is two years for some people. I would never run oil in cold climate for two full seasons, synth or not.

In conclusion, I would highly recomend a full synthetic oil for a fresh or modern engine, and I wouldn't for an older engine. And don't be fooled by semi-synthetic oils. They just dump some synthetic additives into dino so they can use the name. A complete waste of money.

Take this as just another story and POV but...

I had my short block built by DSS Racing, they told me do NOT break in the motor with synthetic oil. He said change the oil after the first 100-200 miles, then run it up to a thousand before converting. He was a big proponent of running synthetic though. He said he tears down his race engines after about 20 runs in the quarter and can seldom see any...ANY...signs of wear caused by friction.

I am a true believer in Amsoil. I have 91 Ranger P/U that had 150,000 on it when I started using Amsoil in it. It now has 260,000 miles on it and has never
been rebuilt. It never has developed any leaks either as so many people have said dont put synthetic in a old car. I think I have proved them wrong. It is drip free. I would never change back to conventional oil.

On bikes, it's the SJ-CF you have to watch out for

Max Power said:

Hack, synthetics have a number of benefits. First, they are far more slippery. Anyone who has tried to use a full synthetic oil in a bike with a wet clutch can tell you that. Because they are so slippery, your engine offers less friction or resistance to turning, yielding more horsepower and better fuel economy. It varies by engine design, but all engines can benefit.

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I remember doing this with motorcycles a few years back, and finally settled on Mobil 1 15w-50, without the "CF" designation. As I remember, the CF stands for "Conserving Friction" and can help mileage and wreaks havoc with a wet clutch. I broke it in with dino oil, and have been running Mobil 1 for 14,000 miles or so with no clutch probs. Interestingly, my buddy, who bought the same bike from the same dealership on the same day, and runs moto-specific dino oil, swears that my bike has more power than his even though it has more miles . . .

The motorcycle guys dig Mobil 1 too, and I have heard the same good stuff about amsoil.