hoot85

I Switched To Mobil 1 Synthetic Motor Oil On My 85 And Noticed A Nice Differance In Peformance And Quicker Start- Ups. However, The Very Thin Synthetic Is Finding Its Way Out From Differant Places And Was Wondering, Once You Go With Synthetic, Can You Switch Back To Regular Motor Oil?
Thanks In Advance.
John

88JDO

Shouldn't be a problem.

TheCorvetteKid

Of course you can.

But don't expect your oil leaks to magically "go away". They will still be there.

hoot85

YES I UNDERSTAND THE LEAKS WON GO AWAY BUT I WAS FORWARNED IF YOU HAVE A LEAK, (I BELIEVE ITS THE PAN) AND YOU SWITCH TO MOBIL 1 YOU WILL HAVE A BIGGER ONE AS ITS VERY THIN.
COULD YOU RECOMMEND A PERFORMANCE OIL FILTER?
THANKS
JOHN

vader86

Yes but your leaks will not disappear now, you'll have to have them fixed.

M1 is not thin, it has detergent packages that eat away deposits inside the engine, these form over gasket materials as the gasket deteriorates and M1 removes them. The engine itself is far better off with M1 in it.

If you want a performance filter, I use the K&N.

AORoads

No prob going back to dino oil. Leaks may or may not go away. It may actually be old news that synthetic helps/produces leaks. If your car's gonna leak, it's gonna leak. Perf filter is K&N or Mobil One, among others. I use the latter. I've heard others use Wix, etc.

grayml

You're going to be better off $$$$ long term to fix the leaks and keep the M1. Ever seen comparison pictures of a torn down engine using M1 at 200K miles vs an engine using dino oil at about the same mileage? The dino oiled engine was a mess.

TheCorvetteKid

You were warned correctly. Even if you didn't actually have a leak, but one that was immanent, the Mobil 1 would have found it anyway.

That's why some mechanics will tell you that unless the car is somewhat new or has a relatively recent rebuilt engine, not to switch to full synthetic oil and instead try a semi-synthetic first. If, after a few oil changes you don't see any (new) leaks, then you can try a full synthetic like Mobil 1.

But regardless, by the sounds of it you still have a leak that needs to be fixed (unless you can live with it the way it is).

I can tell you what filters I tend to stay away from. From tests I've seen, the regular Fram filters (the all-orange ones) seem to be some of the worst on the market. I would also stay away from Bosch, STP, and the WalMart store-brand oil filters. They tend to be of poor construction and don't seem to filter too well either.

I have read very favourable reviews on (funny enough) Mobil 1 oil filters, as well as the Fram X2 filters. The K&N ones are quite good also, but they don't filter down to the same micron level as the Mobil 1. Amsoil also seems to make a good filter too.

I personally use AC Delco filters. They aren't the best, but they aren't the worst either.

hogs29

Thinking back a couple of days to dndrsn's thread "Let me get this straight", you could do the same type of thread containing all the myths about synthetic oils. And while there are a few that are true (break in an engine with standard oil, not synthetic being one) most are completey untrue. The sad part is, I've met several very good mechanics that buy into some of these myths. This one of not being able to switch back to regular oil, and the one about synthetic oil causing dramatic sludge buildup are the most commonly believed.

Fact is, as everyone here has already responded, you can switch back to regular oil. In fact, Mobil 1 says you can switch back and forth between the two types all you want, and you could even mix the two during an oil change.
As for extreme sludge buildup, that's almost always caused by drivers thinking that because they have synthetic oil in their engine, that they can go an extra 3-4,000 miles between oil changes. It doesn't matter what type of oil you run, if you wait that long between changes, you will get sludge buildup, and lots of it. Now I don't know what these new high milage formulas are all about, but I'm not buying into it just yet. I still change my oil every 2,500-3,000 miles.
What Mobil 1 does say though, is that they highly recommend you use standard oil when breaking in a new engine, right up until you get at least 500 miles on it. They say synthetic oil will not do that job properly because of reasons I'm not smart enough to understand.

For filters, I love Hastings. A lot of SCCA racers I know won't use anything but Hastings, so that has to say something.

CentralCoaster

Personally, I think he'd be far better off without oil leaks.

"Mobil 1 doesn't cause leaks, it just finds them."

Either way, it leaked after putting Mobil 1 in it, and it's a sunovabitch to chase em down. No thank you.

AORoads

with all due respect here, hogs, hate to say it, but you're talking myths!

Do you know which was the first American production car to use Mobil One oil from the factory? Depending on what year C4 you're driving (assuming you're driving one) it was Corvette. And Porsche straight from the factory before Corvette. And many cars since then, from the factory, first fill is synthetic.

I'll take your word for it that Mobil says somewhere on its packaging not to use its synthetic for X miles in a new or newly-rebuilt engine. I've not seen it though.

TR Vert

There is no issue with going back. however if your reason is leaks, I'm sorry to say they are with you for a while. The enhanced detergency, cleaned up your engine and exposed some leaks that have been plugged with sludge. until that again builds up with dino oil.... you will still have leaks until you fix the problem.

vader86

He's not talking myths, you just dont know why the LT1 came with M1.

When GM designed the Gen II SBC, it was built with tighter tolerances than the earlier generation, and this allows use of synthetic oil and the rings will still seat. They then deleted the oil cooler because the synthetic can handle about 50F hotter temps.

NT Vettman

Here is a study Mobil 1 vs Amsiol. Long reading but interesting. Final conclusion Mobil 1 is better

http://neptune.spacebears.com/cars/s.../oil-life.html

runner140*

Yes you can but why would you. Mobil 1 has a detergent that disolves deposits and tend to keep your engine clean. Don't try to reclog the leaks but fix them.

hogs29

It's not on their packaging, it's in a pamphlet they provide to their dealers. And all the above mentioned cars were given plenty of run-in time at the factory, so what we think of as first fill could be with synthetic. They might not get 500 miles worth of run-in at the factory, but Mobil recomends that to shops and everyday Joe's because almost none of them have the equiptment or the expert know-how the factories do to say when ready is ready, so 500 miles is used as the safe marker point. Mobil has it in bold type on their pamphlet "DO NOT USE MOBIL 1 TO BREAK IN A NEW ENGINE" and follow that with their instructions for new engines. And when a company says not to use their product at any given point or time, I believe it because they obviously have good reason to do so.
All you have to do is go to any oil change shop that uses Mobil 1 and ask to see the pamphlet. This came in an envelope along with the Material Saftey Data Sheet and some advertisements for other Mobil products. If they havent thrown it away by now(we got ours about 4 years ago) they should have no problem in letting you see it.

hogs29

Well, all this discussion of synthetic myths got me to thinking today, so I looked for the pamphlet in the hopes I could scan it. Pamhlet is long gone, so I went online to Mobil's website, where they have a myth link.
One of the myths listed is "You should break in your engine with conventional oil, then switch to a synthetic oil like Mobil 1." to which their response is "You can start using Mobil 1 with SuperSyn Technology in new vehicles at any time, even in brand new vehicles."
After reading this, I decided to contact them, because I so clearly remember them saying not to use Mobil 1 for breaking in new engines. The rep, I spoke with said that Mobil's stance has not really changed much on that, but they felt the need to be much more specific in their answer. The original statement of never using Mobil 1 to break in new engines was a very broad statement. To the vast majority of comsumers, a new engine is what comes in their new car, or what they get replaced at the dealer when their truck with 8,000 miles on it throws a rod. Since the overwhelming majority of comsumers does not do their own mechanical work, they made sure to now state the words "new vehicle". They still stand by their original statement of using conventional oil for break-in of new engines, that were assembled and not purchased as a complete unit from a company such as Goodwrench, Edelbrock, or Jasper. Every engine manufacterer does a break-in session with their engines, whereas by building the engine yourself or having a machine shop put it together for you, there is no sufficiant break-in done out of vehicle, unless the shop has an engine dyno, and most do not. So Mobil still recommends using conventional oil in those cases.
This is a myth that is still a myth, but is not a myth. It all depends on the defintion of "new engine".

Long winded, I know. Sorry.

AORoads

Actually, Hogs, you did clarify the question/issue. In other words, IT DEPENDS. What engine is a new engine, and whether it is in a new car are what makes or breaks using Mobil One. As to mfrs. sufficiently "running in" their engines, well, maybe. But I don't think so. At least not at the Corvette assembly plant. Maybe they do it somewhere else though. If you say Porsche runs in their engines, I'd agree with you. But that's not the reason they can/do use synthetic oil.

I believe it has more to do with what Vader said, tighter tolerances. Which I did know, btw. incorrect assumption on your part, Mr. Vader.

You obviously did some good homework by contacting Mobil and they stated what they did which means in most cases it's ok, but in some cases of rebuilt engines (or even possibly some crate engines), break in oil is still required.

Thanks.

Morley

When I bought my GM crate engine it said to use mineral base oil for break-in (500 mi), then whatever you wanted.
Every engine mfg runs each and every engine they build, its part of their QA programs. How'd you like to buy a brand new $50k Corvette and have the engine not run when you went to pick it up, or have not make near the advertised power? They are all test fired and run for a short period of time to ensure; no leaks, power production, and proper running.

AORoads

No argument there, Morley, but run in for somewhere approaching 500 miles is a whole lot diff than starting up the engine to ck for leaks and running it for a few minutes, wouldn't you agree? I didn't say they, the mfrs., don't start the engines.