How old is too old to switch to synthetic?

[TheJMan]

I have a 1993 4.0 that has only been changed with 10W-30 conventional oil its entire life. It has 79K miles on it now and I'm wondering if it is too late to switch to a 5W-30 synthetic? The engine uses almost no oil during the 3K mile intervals.

Also, I was cleaning out our garage and found some old AC Delco oil filters that are about 5 to 6 years old and have never been used. Should I toss them and get new ones or are they safe to use? I'm just worried about the rubber gasket being cracked or damaged from sitting in the heat for 5 or 6 years.

One more thing, is it safe to go 6K mile intervals on synthetic with no problems?

 

[Nicaraguense]

That shouldn't be too many miles

That shouldn't bee too many miles. Especially if it was taken care of. As far as the 6k thing. Woah, if it is Mobil one or inferior don't Amsoil offers a 7,500 mile package and believe it or not a 25,000 mile package and both are perfectly safe. Now, with already 79k, you won't get the insane 600k - 800k out of your engine with Amsoil like you would have had it been put in at 0, however you will get more miles. If it was taken care of, it should be no problem. Don't do any less than Mobil 1. That is to say my recomendation (take it with a grain of salt) use Amsoil or at least Mobil 1, anything else isn't wort the synthetic price. The others just can't even compete. Castrol Syntec, in the commercials if you pay close attention they always compare to conventional and never to other synthetics ¿could that be saying something about their product? I really think so. Anyways as long as there is no serious wear, the thing wasn't dogged, it was taken care of 79k I don't think is too late. I started mine at 62 (I think the previous owners should be shot for putting Pensoil 10-30 garbage in a bottle if you ask me in a perfectly good brand new Exploerer.

 

[TheJMan]

I bought Quaker State, have used it before in a lawn mower and I used the exact same oil (5W-30 synthetic) and even after sitting for two weeks it starts up on the first pull every time. The old stuff I had was so bad, it took 5 or 6 pulls for it to turn over and it ran kind of rough, but this stuff has really smoothed it out.

I know, experience with a lawn mower is not the same as an automotive engine, but it made a huge difference in the way it ran.

 

[Magicfan25]

Quaker State..honestly Id think twice on that one..they may have changed, but they used to make a HORRIBLE product. We lost SEVERAL diesel motors to it. Upon tear down it had turned to all kinds of sludge in the engine (it was the correct weight and all). Switched oils and have NEVER had this problem again.

If you go the extended drain intervals you still need to change the filter at the regular mileage and top off your oil unless you get one of their remote dual filtration systems from amsoil.

 

[Nicaraguense]

Hey YES

ANOTHER AMSOIL USER. SO I AM NOT A LOOSER AFTER ALL YES. I plan to change the Tranny fl and Axle Grease later. I felt rather comfortable with the fact that they came factory filled with synthetics. I just don't have any money at all right now.

 

[Sonny]

Originally posted by TheJMan
I have a 1993 4.0 that has only been changed with 10W-30 conventional oil its entire life. It has 79K miles on it now and I'm wondering if it is too late to switch to a 5W-30 synthetic? The engine uses almost no oil during the 3K mile intervals.

Also, I was cleaning out our garage and found some old AC Delco oil filters that are about 5 to 6 years old and have never been used. Should I toss them and get new ones or are they safe to use? I'm just worried about the rubber gasket being cracked or damaged from sitting in the heat for 5 or 6 years.

One more thing, is it safe to go 6K mile intervals on synthetic with no problems?

I would start using Valvoline or Pennzoil, stay with the 5w30, with Az. Temps you will be okay. Do a Motorcraft filter and oil change every 3k from now on and it should go 175k easy. Synthetic could cause some oil leak problems, with an older motor with low miles but old seals. Throw the old filters in the garage sale. I change my Syn every 3k.

 

[X~FACTOR]

Originally posted by TheJMan
I have a 1993 4.0 that has only been changed with 10W-30 conventional oil its entire life. It has 79K miles on it now and I'm wondering if it is too late to switch to a 5W-30 synthetic? The engine uses almost no oil during the 3K mile intervals.

If you are having no problems with conventional oil so far why switch? What benefit are you expecting by switching? Just curious...

 

[aldive]

I highly recommend going full synthetic.

 

[rydinhigh]

I switched to synthetic oil when I had 75k miles on my beat. 34k miles later and still no problems. I am running amsoil oil and highly recommend it.

 

[Hartman]

I run Mobil 1 synthetic blend but I don't see the need to switch to full synthetic. It's not worth risking oil leaks at the seals.

 

[Alec]

Reasons not to switch to full synthetic:

*Any previous oil leaks
*Over 30k miles (I'm really careful)
*You live in a dirty climate or often drive in dusty or foggy conditions so your oil gets dirty faster.
*you're gonna change it every 3000-5000 miles anyway
*you don't often abuse the truck

I always ran dino oil in Splat, changed it every 3-4k miles and never had a problem. It had some minor pinhole oil leaks (never lost any between changes) which made me very wary of the switch.

 

[NOTAJP]

Originally posted by Hartman
I run Mobil 1 synthetic blend but I don't see the need to switch to full synthetic. It's not worth risking oil leaks at the seals.

I run the synthetic blend in my axles and well worth the money. I will run full synethic in my new engine and tranny when they finely give up (150k+ miles). For now I still run conventional oil.

As far as a full synthetic in the engine, you could get oil leaks. I say could because it may not happen but more than likely you could find oil leaks. Here's why:

Conventional oils are natural products so the molocules are not always the same size and shape. If you were to see this under a microscope you will see crude shapes and sizes. This is perfectly normal and just fine for engine wear.

Synethic oils are just as the name perscribes; man made. Each molocule is structured, refined, and exactly the same small shape. This makes for a very smooth oil and guarenteed less friction.

What does this have to do with oil leaks? When the conventional oil finds a microscopic hole anywhere in the engine, most of the time it fills it up. Synethic oil doesn't have to larger specs of conventional and cannot clog the hole (in lamen terms). It is natural for it to flow out any hole it finds. Synethic's don't cause oil leaks, they just find it easier. I used to have very upset customers when I ran a parts store from people who switched to synethic oil late in an engines life. It happens. Would this happen in your engine? Who knows for sure. If it has been well taken care of and you replace seals when finding a leak, then you will be just fine switching. I would consider a blend motor oil so you will have the benefits of both and half the cost.

 

[Alec]

Very good explanation.

 

[aldive]

REASONS FOR USING AMSOIL
Copyright © 2000 By Ray Thomas

There are lots of good reasons to use AmsOil. The biggest one is that it saves you money in every department and helps your car run better, cooler, longer, and cleaner. Below are the seven most important reasons why if you want to keep your car running for a lot longer and save money doing it, you'll use AmsOil.

1. GAS MILEAGE SAVINGS: AmsOil will save you about 2 miles a gallon (national average based on 14 MPG without AmsOil.) in fuel costs. As soon as you put it in the engine picks up a couple hundred RPM because of reduced friction. Idle it back and there's your fuel savings.

2. LESS MAINTENANCE: This friction reduction translates into a cooler-running engine because it isn't working as hard. You'll be going to the mechanic less often and that can mean big dollar savings.

3. CLEANER RUNNING: Synthetic lubricants are by their very nature a superior detergent in your engine. An engine that runs cleaner will run better and more efficiently.

4. IT DOESN'T "SHEAR BACK": Engine parts attempting to rub against one another with only a thin film of oil between tend to put a lot of pressure on that oil, causing it to "shear back" or get thinner and losing its "film strength." (Film strength is the measurement of just how much pressure moving parts can exert on each other before the film of oil is broken and metal-to-metal contact is made, causing engine wear.) Synthetic oil has a demonstrated film strength FIVE TIMES THAT OF CONVENTIONAL FOSSIL OILS. That means it resists "shear-back" much better.

5. EASY WINTER STARTS: This is especially important where temperatures regularly get below zero, but is also important anywhere there is cold weather in the winter. How would you like to have a car that starts as easily in the dead of winter as easily as it does in the summer? AmsOil will not "gum up" like fossil oils do at any temperature below zero. AmsOil will remain liquid and cling to engine parts down to 60 degrees below zero. So your engine is not turning against gunk and is not working any harder to start your car on the coldest days than on the warmest summer days. This also makes your battery last longer since it isn't working as hard either.

6. NO MORE "DRY STARTS": No longer will your engine suffer from that split second of no lubrication when you start it that results from the oil having dropped back into the crankcase when you park it. AmsOil, with its better film strength tends to "cling" to engine parts so there will always be a film of oil between your engine parts. It has been proven that this split second of metal-to-metal contact is responsible for 75% of all engine wear.

7. NO MORE VAPOR LOCKS ON HOT DAYS: With a flash point of 509 degrees Fahrenheit, AmsOil is still running cool on the hottest days which pretty much eliminates the tendency toward vapor lock due to engine overheating. And with today's "four-bangers" operating at temperatures above that recommended for most fossil oils that can be a big benefit.

 

[aldive]

If you want to learn more about oil, visit http://theoildrop.server101.com/cgi/ultimatebb.cgi

There is some great info and helpful reading.

 

[Hartman]

Again Al, none of that means anything if you're leaking it all out of the seals. There are good benefits if you use it on a low milage vehicle but it's risky on high milage vehicles.

 

[aldive]

That synthetic oil causes leaks is not a proven fact.

 

[RobertF]

Hartman and aldive check out NOTAJP's post. What he said is right, it doesn't CAUSE leaks.. it's just much better at finding them.

 

[NOTAJP]

Originally posted by aldive
That synthetic oil causes leaks is not a proven fact.

Synthetic oil does not cause leaks. Read my last post above.

 

[NOTAJP]

Hartman didn't mean synethic oil causes leaks. Synethic oil ha sthe potential to find leaks in seals. If a high milage engine leaks a little (and they do) then there's potential for the leak to become severe and that would be money down the drain as Harman was implying.