Oil change every 3k miles...

Here at work our trucks to include a couple 5.4L's run all day long and never leave the city most of the time it is stop and go traffic with just as much idle time. I run convoy parasynthetic 5w30 made by conklin we change the filters at 2500 miles and the oil at 15000 in gas motors and the diesels run 4000 on the filter and 30000 on the oil. We have been using this for 4 years and havent lost a motor yet. We have periodic oil samples taken and the oil retains 96-99% of its additive qualities.

The main reason you can put extended miles on synthetic/parasynthetic oil is that it doesnt loose its additive/detergent properties like conventional oil does. As long as you change the filter every 2500 or 3000 miles you should be able to run 10k or more on the oil. You can change from conventional to synthetic and back again without harm to the engine or seals. But if you have a new car do not run anything other than conventional oil during the break in period otherwise the rings will not get a chance to seat correctly.

I have used Mobil 1 every 5,000 miles since the car was new. 98K miles and counting. Runs great and still doesn't use any oil between changes.

This is a subject on which there are probably as many opinions as there are people. It's kinda like asking a roomful of beer drinkers to name the best beer (free is always good).

Here's my $0.02 worth:
1. A 3,000 mile oil change interval largely dates back to a point in time when technology, for both engines and lubricants, was nowhere close to the level that we enjoy today.
2. The last car that I recall seeing a no-kidding 3,000 mile oil change interval listed in an owners manual was the original VW beetle. In an air cooled engine, the oil also serves as the cooling medium, and as such it is subjected to much more punishment (heat related breakdown) than the oil in a water-cooled V-8 engine that is either unmodified or slightly modified. Anyone who has ever owned air cooled VW can tell you how critical 3,000 mile oil changes were to keeping those cars alive. Even the 86 Nissan 300ZX Turbo that I owned called for a 5,000 mile interval, with a 3,000 mile interval if the car was operated under severe conditions.
2. Today the 3,000 mile oil change interval is largely an advertising scam. Everyone who recommends it is someone who stands to profit from the average motorist changing oil prematurely (not that I am advocating that we Mustang owners are average motorists or that our cars are average by any means!). Jiffy Lube wants everyone, from the soccer mom in her minivan to the 4x4 driver who tows a cabin cruiser, to come in every 3,000 miles. So does Wal-Mart, Sears, Quick Lube, and everyone else who stands to make a buck off an unneeded oil change. Besides, there's always the angle for those businesses that perform automotive repairs to use the opportunity of having the customers car on the lift to identify all of the other work (genuine or otherwise) that the car needs... And, how many of us have seen dealer service departments that recommend maintenance at an interval far shorter than what's in the owner's manual? They usually try to tell you that it has to be done that way to preserve the warranty, which is total BS. As long as you can show that your maintenace has been performed in accordance with the factory-recommended service schedule, they cannot use this to base denial of a warranty claim. Sorry if I went overboard about this, but being in the military, it really sets me off when less than honest auto service &/or repair businesses (including dealers) take advantage of our young servicemembers, or even more so their wives when they are deployed, by overcharging or performing unnecessary repairs.

I seem to recall that the 66 Mustang 289 Coupe that my family owned when I was growing up (and that I not only learned to drive in, but performed my first-ever unassisted oil change on) called for a 5,000 mile oil change interval.....

Having said all that, I still change mine somewhere between 3500-4000 miles, but do so largely because I have the time,facilities and inclination to do it myself. Besides, I think it was ingrained in me during the point in my life when I was a starving, VW Beetle driving college student.
If I ever reach the point where I am at the mercy of the quick-lube / automotive service & repair industry for oil changes, I will probably let the interval slide to 5,000.

I use Mobile 1 change it 1 time a year 10000 miles and change my oil filter at 6 months or 5000 miles.
I now have 70k on the car from new. From what I can see inside the oil fill the inside of the engine is very clean with no sign of varnish and 0 sludge.
I have been supercharged for the past 3 years still do not burn more than 1 qt per year.

Dwayne

I change the oil every 6,000mi and change the filter every 3,000mi. No probs here so far (use Amsoil 5w-30)

Every 3000, oil and filter using API approved regular dinosaur oil.

If I did motorcross or pulled a trailer, I'd switch to synthetic.

I suggest Mobil 1 0w20 every 5000 miles with a filter change in between at 2500 miles. Can't go wrong with this.

SLOW98GT said:

I am pretty sure you can't change change back to conventional oil once you have used synthetic. I heard it can ruin the seals. Anyone know for sure.

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I change mine every 3,000 miles and I thought I'd do my car a favor by using Royal Purple Synthetic oil, but after only 1,500 miles I had oil leaking so bad out of the passenger side valve cover...that oil was actually puddling up on my catalytic converter. I changed BACK to Motorcraft 5w30 conventional oil...and ordered a set of valve cover gaskets (thinking I'd replace them at the next oil change), but during the last 1,000 miles the leak has slowed to just a tiny sweat. By my next oil change, I figure the leak will have sealed itself completely.

The leak is not from the synthtic oil.......the synthetic just showed you where a bad seal was. Do you really want sludge to seal up a leak for you?

01BlkGT said:

I change the oil every 6,000mi and change the filter every 3,000mi. No probs here so far (use Amsoil 5w-30)

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same here only with mobil 1 instead

[QUOTE='96&'01Stang]The leak is not from the synthtic oil.......the synthetic just showed you where a bad seal was. Do you really want sludge to seal up a leak for you?[/QUOTE]


At 17,000 miles...I don't think the prior non-leaking properly torqued valve cover seal is/was bad. Probably a whole lot more like the smaller moleculed R134 that oozes *through* prior non-leaking R12 AC hoses. "sludge"? Yeah...right. My motor (inside and out) is probably cleaner than most car interiors.

When changing your own oil in a GT, how high can you lift the front end and still have the oil drain properly. I have a set of Rhino ramps, will these be sufficient. I have always owned trucks prior to my GT and I could easily just lay underneath and get to everything.

NasaGT said:

Motorcraft 5w20 synthetic blend here. I would like to use Mobil1 but they don't make a 5w20 yet. So far I've only changed the oil twice at 500 and 3000 miles. I'll be changing every 3K from here on out.

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Same here. The Motorcraft Syn blend isn't all that expensive, so I change every 3K.

Synthetic oil will not leak any place that non-synthetic oil is not leaking unless there is build up - whether it is 17,000 miles or 170,000 miles. There was either an existing problem that you didn't realize, or there was buildup in the cover area.

The proper use of synthetics and high quality filters can allow you to go much longer than the numbers almost everyone has specified. I'm not going to get into that debate again, but it has been clearly shown that the use of higher quality oil and filters can not only extend drain intervals and save money - but protect your motor better than frequently changing products of a lower caliber (ie Fram filters).

pdl2flr said:

When changing your own oil in a GT, how high can you lift the front end and still have the oil drain properly. I have a set of Rhino ramps, will these be sufficient. I have always owned trucks prior to my GT and I could easily just lay underneath and get to everything.

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So it can be as clean-as-clean-can-be? Easy...drive it up "flat" on a Hunter 4 post lift.

BuffaloZone,
I would get the valve cover gasket changed if I were you. Your car should still be on warranty. If not, it doesn't cost much to change the valve cover gasket. You don't want to have other problems arise because you didn't fix this problem.

snkypete said:

Synthetic oil will not leak any place that non-synthetic oil is not leaking unless there is build up - whether it is 17,000 miles or 170,000 miles. There was either an existing problem that you didn't realize, or there was buildup in the cover area.

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Again, there isn't a "build up". For example, have you ever noticed how the Synthetic-filled automatic transmissions seem to always have that strange fluid "sweat" all around the pan gasket area? And it's not (always) "build up" in the transmission, because I've seen it on pans from 5,000 miles to 150,000 miles - on nearly *every* single pan (even with the expensive reusable gasket). But on the non-synthetic pans...no, I haven't seen that "New Car sweaty" look on nearly every single vehicle. Also, I must have had "build up" around every single properly torqued valve cover bolt...because with the Royal Purple, they started to puddle up just a bit - no puddles now...since I removed the Royal Purple.

Well Royal Purple doesn't even contain the detergents that most of the other synthetics contain (why it should be used for racing purposes only) so again, it is not a fluid issue. You have some other problem - most likely the gasket like someone else stated. Because it does not do it with non-synthetic doesn't mean the problem is with synthetic fluid. Synthetic fluid will not cause a leak - that is almost as big of as oil has to be changed every 3,000 miles.

Ron Jeremy said:

BuffaloZone,
I would get the valve cover gasket changed if I were you. Your car should still be on warranty. If not, it doesn't cost much to change the valve cover gasket. You don't want to have other problems arise because you didn't fix this problem.

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...I don't think the prior non-leaking properly torqued valve cover seal is/was bad. Probably a whole lot more like the smaller moleculed R134 that oozes *through* prior non-leaking R12 AC hoses.

snkypete said:

Well Royal Purple doesn't even contain the detergents that most of the other synthetics contain

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So...the sludge "build up" theory is out the window?

You have some other problem - most likely the gasket like someone else stated. Because it does not do it with non-synthetic doesn't mean the problem is with synthetic fluid. Synthetic fluid will not cause a leak - that is almost as big of as oil has to be changed every 3,000 miles.

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As I stated, for years now, I've seen that "the problem is with synthetic fluid."

"For example, have you ever noticed how the Synthetic-filled automatic transmissions seem to always have that strange fluid "sweat" all around the pan gasket area? And it's not (always) "build up" in the transmission, because I've seen it on pans from 5,000 miles to 150,000 miles - on nearly *every* single pan (even with the expensive reusable gasket). But on the non-synthetic pans...no, I haven't seen that "New Car sweaty" look on nearly every single vehicle. Also, I must have had "build up" around every single properly torqued valve cover bolt...because with the Royal Purple, they started to puddle up just a bit - no puddles now...since I removed the Royal Purple."

Just because you might not see a steady stream pouring out of a transmission gasket...doesn't mean that synthetic won't be more prone to sneak-past the seals...much the same way that R134a freon can actually "float through the pores" of an R12 AC hose...but thanks for your concern.