This point indicates a PROBLEM. If you have buildup (not good maint) or seal swealing that makes the seals NORMAL and then a leak occurs you have a mechanical issue that neeeds resolved. High mileage oils are made to make seals sweal so those that dont want to correct obvious problems can through in the oil and forget it. Kinda like that radiator "Fix a seal" crap.

I dont have issues with mine. I have been using AMSOil since its second year of life (Mobil 1 prior to that) so I have no worries.

 

You can look at it any way you want to. But I have read here on the org and other sites about the leaking problem after switching to synthetic.My 2000 se bought 15 months ago was a repo and looks like it was taken care of but bought with 136000 miles and now 181000 with no leaks at all, I personally don't to take the chance. Remember Arco graphite motor oil ?? Years ago.UPS bought barrels of it for there fleet and had to replace many motors because of it. I do agree that todays synthetics are supperior to conventional oil but you must know that you are taking a chance on leaking with a high mileage car. If you don't want to listen to other Org member's some as stated in the oil changing business,What the hell are you looking for here at the org???

 

http://www-d0.fnal.gov/~jkrane/cars/synth_survey.html another link to back me up but you don't have to look or believe anything you don't want to.

 

I have an 04 max with close to 70K and currently use 5w30 Castrol Full Synthetic. Would you guys recommend something better?

 

no...

 

70 k I think your pretty safe using synthetic and I do like synthetic.

 

By todays standards 70 k is not high mileage. I would definatly recommend synthetic for you.

 

For what its worth... Nissan does not say or state that your motor will have a longer life if you use synthetic.

The key to keeping your car running well is routine maintenance.

Since 130K miles, my car(01 GLE Auto) has been getting a dose of supertech 5W-30 with supertech filter and shes now at 186K.

If you use synthetic its not going to do any magic on your motor. Its not a BMW or Audi or a car whose owner's manual states it "needs" full synthetic oil.

Good Luck!

 

I use Castrol high mileage in my max and use synthetic every once in a while to clean the engine. I do this because a mechanic told me that the cleaning agents in synthetic will deteriorate the engine seals if used regularly. I always run the synthetic for shorter intervals (3k at most) because the cleaning agents cause the oil to spoil quickly.

 

 

Make it stop! If you read your damn Owner's Manual it simply states that you can use any "mineral" based or "synthetic" based oil as long as it has the API certification and is of the recommended viscosity for the expected ambient temperature range, AND......to "not mix mineral based and synthetic based oils in the engine at the same time". Plus......the info that is still circulating on every car forum in the world re synthetic oil leaking past seals after switching from dino to synthetic oil is from issues dateing back 15 or more years ago. Forget it.

 

/agree


I remember this exact same arguement over 2 years ago here. Back then (and possibly still now, though I haven't checked), www.bobistheoilguy.com ruled the world of motor oils. All these guys talked about all damn day was oil.


There is no damn need to switch to synthetic oil after 100k miles. There simply is no advantage to it. It's not like quitting smoking where it will reduce your chance of cancer; read: you will not make your engine life better by using synthetic oil after 100k miles of regular oil.

Your car will not go faster.
You will not save money.

There simply is no reason to switch after that many miles.

 

Did you even read this?

It said of the cars that switched (74 samples), four had problems. Four out of his unsubstantiated test (it always nice to see how data was gathered).

Here is the break down of those four cars, paraphrased:
1) Rebuild motor, bolts not torqued to spec. Leak disappeared
2) Mechanical part failure replacement. Leak disappeared.
3/4) Porsches (of very old vintage) and leaks not traceable. Problem still occurs.

Part of his conclusioni:
First, engines with few miles on them are not immune to leaks. Conversely, switching a high-mileage engine to synthetics does not guarantee oily spots in the garage.

Your document proves my point. That synthetic does not cause problems, it reveals them.

He makes a non-annotated quote about synthetics containing oil swellers (as part of his Supplemental Information), but I have yet to see that anywhere.

Whether or not you follow the synthetic religion is a never ending debate. There are zealots on both sides and neither side will yield. But stating that synth causes leaks is bunk.

 

Give it up Colonel,What oil company do you work for??? If you don.t work for a oil co you sure as hell act like you do. Lots of people have spoken and its like your getting paid to push for synthetic. I bet if people serch your posts the truth will come out.

 

What is the "need" to switch to synth under 100K miles?
Does all wear suddenly cease at 100K?

 

You did not read further down in the conclusion <The rate of occurance of leaks appears to be high enough to merit caution when switching a motor from natural oil to synthetic oil, and a general warning to those interested in switching.> My argument only states that the risk exsistes and it does.

 

For me and just for me, in the last 2 years there has been a push to sell-give away synthetic oil...extreme discounts and free oil.

I invested in them and I probably have a ton of them (like 60 Quarts at least).

I have started using synthetics on 3 out of my 4 cars, 2 years ago. My observation is that the SYN oil does not turn black as quick as the dino oil and I am pretty confident with going up to 8K easy.

For my 165K 00 Max, I intend to switch to synthetic because I am running out of cheap dino oil.

Now you guys are making me think twice. And if I decide to stay with dino oil, I will be looking for the dino specials which are in abundance these days.

Reserve the SYN-DINO discussions for BOBISTHEOILGUY.

Peace!

 

Done

 

You are stating that syth CAUSES leaks. I never said that switching does not have leaks appear. I said that leaks that appear during a change are the result of a mechanical issue that needs repair.

 

I've switched multiple cars to synth and back never had a single problem. There's so much myth, lore and smear about going from one to the other.

I like syn cause it withstands shear and heat much better than dino oil. I run syn ONLY in my VR-4 and just switched my Maxima to Shell Rotella T syn 5-40.

 

Synth may reveal leaks.

 

Yes, that is my stance. Its what I have been trying to hammer home.

 

I've been using this new fangled "wave of the future!" synthetic oil since my first car, in 1980.
No "new" leaks.

 

The advantage to synthetic oil vs dino oil is that it shears down at a much slower rate. This is why you can go much longer before an oil change with it, and some of the hardcores will argue that it lubricates better. Switching to synthetic oil on a relatively low mileage car will (in general, but not all case) have the engine running more smoothly when it gets to higher miles (like 100k+) than if it had been run on dino oil. By the time a car has 100k miles on dino oil, it's already beyond the stage where "better lubrication" is going to offer the preservation needed to give that advantage.

 

By that logic, there's no point to continue using synth past 100K, even if used in the past.


Seems you DO believe wear stops at 100K...

 

Guys,

Let me start by saying that I am in the lower half of knowledge based people on this forum. However, I thought I would offer an outside look:

I worked for a machining company that operated high velocity, high pressure compressors (24/7). We switched to a synthetic oil (machining oils) in the early 90s from the conventional stuff that we were using and noticed wear reduction in the parts (bearings, part, etc) barely significant enough to offset the cost differential of the oil. We also noticed two distinct things. We had small cases of leaks (3/110 machines that we though were suspect, bubble leak not a gusher) when we switched to the synthetic, but no different from the general ratio we had prior to the switchover. We also noticed a very small decrease in the electric used, which is a direct relation to the friction in the machine. Over the course of the machines life, we noticed no difference in the frequency of times to change gaskets (changed routinely anyway, so may not be relevant).

We only use the synthetic now....but.....internally we agree that the synthetic (increased part life and decreased energy) vs. conventional (cost savings and price differntial) is negligable as we perform maintenance religiously. The extra operational life span of synthetic is meaningless for us as we perform mainetnance long before the would be cutoff for conventional or synthetic. The synthetic certainly is a much, much better selling point when we negotiate service contracts for expensive equipment.

The machines that we operate are far more demanding than the engines in our cars as they are much more loaded and unloaded 24/7/365 in the dead of winter and the heat of summer.

Whats the upshot.....If you switch to synthetic, and notice a leak, switch back to conventional. If the leak continues, there may be an argument that the synthetic caused it or you just may have timed it in/correctly. If you are changing oil every 3000K with conventional and are happy with it, why would you need to go to synthetic in the first place. If you are looking for extra HP out of a high mileage car that an oil would give you......aren't you kidding yourself? If you do maintenance regularly, it seems cost neutral.

I have run M1 10W30 for the past 200880 miles in my 00' SE and get the same mileage out of the tank as I did the day it came off the lot. I get the synthetic becuase I put an oil in the car and stay with it for the life of the car, and I think the likes me better for it becuase most F1 cars run M1 (yes I talk to my car.....AND I KNOW YOU DO TOO).

Figure the cost of an oil change (DIY) is about 8 bucks. Synthetic runs me about $24. Over the 47 oil changes that I have in the car, thats about $750 extra that I probably could have saved.....but I burn that in 1 year at Starbucks easily.

Sorry for the long blaaab, just my opin, but one last question, I have been hearing lately that the additives in most oils interact negatively with teh sea foam treatment....any truth?

 

That's not at all what he said

 

I have always run M1 starting at 500 miles for the life of my cars. Since I only drive ~8,000 miles/year, I change the oil once a year in the spring. No leaks and very earth friendly with once a year oil changes!

 

Thanks for clarifying.

 

Ok hows this:

He simply stated that the long term benefits of running syn is much more apparent the earlier you switch. Also that the later in life the switch occurs the less benefit you would see. (which is true for a dd that doesnt every truly get pushed hard, for a weekend warrior car that always gets pushed harder) He said nothing about wear 'stopping' like you claimed. He said nothing about no reason to switch to dino after 100k.

In the end the only way to know if an oil is doing a good job is UOA. If you are switching from dino to syn wait till your 3rd oil change for a UOA because the higher detergent levels in syn will skew your results on the first 2 OCI.

 

Ok So Just stick to High Mileage then?

 

pretty much, while IMO used oil analysis has shown there are better oils, high mileage is plenty good for what most people here use their car for.

 

What's the selling point of a "high mileage" oil vesus the regular dino?

 

An additive package to "condition" seals to reduce leaks. I am unsure how well it works.

 

QFT.

In my humble opinion, I think anyone considering purchasing a used car with 75k+ miles on it should have the option to get a UOA done before making a decision. Of course, good luck getting that from the dealer... it's amazing what it can tell you about an engine.

 

Well lets spell this out say I have a car with 120000 miles that has always run conventional oil and does have some sludge around the rear seal but does not leak and being unaware of any possible side effects you make the switch to synthetic 2 days later the rear seal starts leaking.Anyone with any experience would say that if you did not make the switch the leak most likely would never happen.Yes the leak was caused by cleaning sludge around the rear seal but it cleaned sludge that would have stayed there with no problem and no leak without switching to synthetic.The risk is there that wouldn't be there without switching.

 

This is an interesting thread to read, lot of opinion being thrown around with some possible data to back that opinion.

My quick web search turned up this article: http://bestsyntheticoil.com/content222.html

Here's the short of it, if you always use conventional oil then switch to synthetic, your seals could have cracks that have been "plugged" by the inferior conventional oil. The synthetic oil will clean away this sludge and over time CAN RESTORE the seals. Of course your results will vary. The seals could be too far gone to be saved by synthetic oil.

Now the kicker, a brand new car with low miles having only synthetic oil after 5,000 miles would never encounter the problem of cracked seals.

 

I have been using synthetic blends ever since I purchased my 2002 Maxima with about 16k miles on it. I can go about 6k miles between oil changes with no issues.

 

Most of what you just said is the reason I say switching to synth on high mileage engines is pointless. Synthetic oil protects against wear at a higher level than regular oil does, this is certainly true. And, of course, wear does continue past 100k miles. However, dino oil is not a BAD lubricant, it actually protects against wear very well. Synthetic is just better at protecting the finer edges, the integrity of the engine. After 100k miles (and this is arbitrary, point is: High mileage car) of wear on regular dino oil, the finer edges are already gone. I would argue that synthetic isn't going to protect any BETTER against wear than dino oil would at those high miles UNLESS those "finer edges" have already been preserved. Hence, why making the switch to synthetic is a switch to be made early on, not later on.

As for synthetic oil repairing seals... I doubt it. Repairing the seals would require polymer adhesive activity... the word "adhesive" and "lubricant" don't really go well together...

Also, by this logic, a car that has used synthetic oil for the life of the car would NEVER see wear in the seals, as it constantly repairs them. I have no doubt that synthetic may reduce the level of wear on the seals, however, I can't see it making a damaged seal all better.

 

I been meaning to give this company a try http://www.blackstone-labs.com/what-is-oil-analysis.php

And should mention I have decided to stick to Castrol High Milage 5w-30.

Anyone use Blackstone in the past?

Edit: I searched for blackstone and VQ35DE and hit this PDF, very valuable information http://www.animegame.com/cars/Oil%20Tests.pdf