Jump to content

Debate of the day: Synthetic Oil Life


Mowgli1647545497

Recommended Posts

So anyone with a new car probably knows the manufacturers, ESPECIALLY the ones who pick up oil change maintenance costs, recommend really long oil change intervals: 5000, 7500, 10,000... I've even heard 15,000 (Mercedes SUV).

 

Curious as to folks' opinions on why this is. My take is manufacturers not wanting to pick up the dime on costs. Also a bit of a bragging factor - longer interval equals perceived better engineering in the car itself. Knowing that the oil that goes into a Kia is the same oil that goes into a BMW, I personally don't buy into that perception: I chalk up the ability to get longer intervals to advancements in oil tech far more than engine tech.

 

But I've had conversations with non-car guys who are convinced that because their bimmer's oil service reminder indicator doesn't come on til 15,000 miles it means their engine is engineered better. Ah well...

 

Personally I change the oil in my cars at 3,000 miles religiously. Synthetic or no. Scheduled maintenance or no.

 

Thoughts?

Link to comment
Share on other sites

I could't agree with you more. Both of my cars get synthetic oil and get it every 3500 miles and one of them is a BMW. I see BMW's recomendation of 15k mile changes as a way to cheap out of maintenance costs on the cars.

 

Crappy part about the whole deal is the M3's oil is mandated to 10W-60 and Castrol is the only manufacturer that makes a 10W-60 because BMW worked exclusively with them when all of the bearing issues started to occur on the M3's and this is part of the solution. Cheapest I can find the stuff online is $10 a quart. Cost $17 at the dealer. BMW will test the oil on engine failures and void the warranty if you're not running the correct oil. The cool part is that I've got a 100K mile engine warranty as long as I follow the rules. None the less...it's still going to get oil every 3500.

Link to comment
Share on other sites

Yep, I agree with you also.

 

Sure, you can probably run some oil to 15,000. But if you have the financial means not to, why would you?

 

Oil is the only thing separating every moving part in your motor from each other. No thanks, I'll change mine at 3000 like I always have.

Link to comment
Share on other sites

I don't know why this suprizes anyone. Consider what screws up oil in a motor. Heat and dilution by gasoline. Synthetic oil is for the most part uneffected by heat, so with a good synthetic, heat doens't factor in. Leaking dilution by gasoline. This was a major factor in the days of the carb. Every time you started it, you had to pump it to prime it, part of the fuel would leak down past the rings because it was intering the cylinder as a liquid. With todays motors, there is no pumping, infact you CAN'T pump it and prime the motor, the computer don't allow it. So flooding a car is also a thing of the past. Since the motors of today burn all the fuel they have go into the cylinder, there isn't really any to dilute the oil. So the oil and additives don't seperate like they use to.

 

Now bear in mind that this only applies to newer cars that are EFI, and STOCK.

Modified engines, fuel systems and carbed motors do NOT fit into the same catagory, there is from time to time some extra fuel in hotrod motors, and you can't expect the oil to last like this in these motors. So, it's ok for a EFI beater, but not for your hot rods.

 

And Chris, I haven't seen the pricing on it yet, but my guess is that it will be $10 a quart for 15000 mile oil. Even though Mobile 1 oil will do it now, for $4.79 a quart. I figure the money thing is a wash.

This really is an advertizing gimic in my opinion, selling a current product that is repackaged at a higher rate, stating something specific that it could do all along.

Link to comment
Share on other sites

I change the oil in my cars at 2500-3000 miles religiously. Synthetic or no. Scheduled maintenance or no.

 

Having access to 2 lifts and being bored on Saturdays is why I do it so often. If I changed oil in my own garage, I'd probably use Synthetic around 4k intervals.

Link to comment
Share on other sites

3K mile is overkill, you don't need to do it that much. Don't buy into the hype the oil companies set forth. ;) I'm ususally 4K - 5K on all of my cars, save the Formula and Mustang, who see oil changes at the beginning of each Spring. They only get a few thousand miles on them over a course of a year anyway. And the Formula is the only one that gets Synthetic and whatever replaces it will as well... graemlins/nod.gif
Link to comment
Share on other sites

desparado's got the call I think.

 

From another forum:

 

Everyone please say this with me, "Oil has MEASURABLE PROPERTIES".

 

I had let the DIC oil life monitor get to 0% and then a little longer (oopsie!) with the warnings popping up everytime I started her up (I haven't confimed this exactly, but *I think* it was 10-12k since my last oil change). File this experience under the stuff happens. Anyway I did the (oil/filter) change and sent in my usual sample (of the used oil) for analysis. All measured spectrochemical and physical measurements were within the accpetable range (after the DIC read 0%), nothing elevated or abnormal. This means (in my case) no need to change (the oil/filter) for the sake of changing (@ 50% life , 5k or X months), cheap insurance or not, oil has measuable properties and if they are within range, then no need to change, esp synth.

 

Link to comment
Share on other sites

Opinions are like assholes, everyone has one! I believe engines (today) run very hot - that has to effect an oil's viscosity & it doesn't matter if its synthetic or not. I change mine every 3,000 miles. I ran a '99 Yukon I'd bought new to 85k, oil never looked baaaad as it got changed every 3k. Plus I can't afford "Rarest Truck on CR's" labor rates! :D
Link to comment
Share on other sites

Des and Mowgil hit it on the head. Only way to end this debate here is if a bunch of people on here with a bunch of different cars did an oil analysis for a few oil changes. They will tell you how much good stuff is left in the oil and how much bad stuff from you engine has gotten into the oil.

 

I know some companies will even suggest whether you go longer or shorter on the intervals. All of the guys over on Audi World w/S4's who do this are running 7, 8, 9kmi. And our engines run fairly hot; this is on Mobile 1 Synthetic 0-w40 for most of them (suggested for our cars is 5-w40). I bet those engines aren't built that much better than just about any other engine on the market (as far as what actually wears down and can get in the oil). I'd be willing to bet that just about any modern car can go quite a bit longer than 3kmi. That's just a way for the oil companies to make more money.

 

Synthetic will be able to take the heat more before it breaks down, that's why I run it. I don't want a track day to ruin my oil when I have to drive home.

 

Does that mean I don’t try to change my oil ever 3-4kmi? No

Do I worry if I don’t have time to get to it until 5k? Definitely not and you shouldn't either (under 'normal' driving conditions).

Link to comment
Share on other sites

Originally posted by Kohones:

Opinions are like assholes, everyone has one! I believe engines (today) run very hot - that has to effect an oil's viscosity & it doesn't matter if its synthetic or not.

I don't have opinions, I have data that proved what I am saying. And what really kills me is that mineral oil (and BTW, some synthetics are made from crude, it's just cracked different)are reused. Coastal and that other cheap ass oil is reclaimed, it's filtered, the additives are put back into it and its put back in motors.

 

Full synthetics still have a breakdown temp, it's just that the motor would need to be melting the hell down inorder for it to be reached, where the regular stuff will fail around 400 degrees.

 

Now, as far as todays engines running VERY hot, is this truth? or is it because you say so? Got news for you, ALL oils, synthetics and otherwise need to reach a MINIMUM of 200 degrees to get the moisture out of them from the condensation that takes place in the motor, so the oils are formulated to reach advertized viscosity at that temp. (that would be the 10 in 10W40... The 40 BTW is the weight/viscosity at 0 degrees).

Now as far as the guys saying that they run their cars "REAL HARD", again, this is a matter of opinion. The SAME MOBILE 1 that go's on the shelf at Auto Zone runs around Daytona for 500 miles at 8500 to 9000 RPM. I want to see the list of who here has a motor that will SUSTAIN 8500 RPM that is not a rotary, and not a bike. I bet this is a short list, and no one here saying that they run their car "Real Hard" is even on it.

Link to comment
Share on other sites

I've been using mobil 1 full synth ever since i got my car and change it everytime my light comes on... app. 4800-5000 miles, can't remember. But the oil always still looks excellent!

 

Now my old probe i would change every 3k w/ just w/e was on sale at the moment and the oil never looked as good as what i put in the coug. Synthetics good stuff, and since i don't have access to a garage anymore and refuse to let anyone else touch my car, it saves me trips back home to change my oil.

Link to comment
Share on other sites

I personally wouldn't ever waste my money on so-called synthetic oil...

 

the base stocks in every oil come out of the same hole in the ground no matter what you buy only the detergent additives are synthetic...

 

my recomendation pick up the cheapest bottle of oil you can find and look at the back if the API service label says SL on it your good to go...

 

your oil change interval should be based on your driving habits if you drive hard or do alot of city driving 2500-3000 if its all highway miles changing the oil at 6000 isn't going to hurt a thing.

Link to comment
Share on other sites

I read somewhere about this guy that works at a Ford dealership and he said that when people come in to get their oil changed at 3,000 miles, he takes their "old" oil and puts it in his vehicles for 3,000 miles. He said that he only buys oil filters; never has to buy oil. I don't know if he was telling the truth or not, but that's what he claims.
Link to comment
Share on other sites

too much thought contimplating what to do !whats cheapera few extra oil changes or a new motor ? change it sooner the better smile.gif ohh and i wondered what all your thoughts on the cut off on the starting milage to start using synthetic oil .... i was told by my boss and the oil company guy that brought us the oil in the tanker truck not to add synthetic oil to a motor that hasnt used it yet after it gets to 75,000 or else it will get blowby... personanly i think it may depend on the car if the car was engineered with better materials itll be fine after that mileage to use it for the first time ...one thing i know for sure is i switched my mothers oil to full synthetic on her 94 ford mini van and it had 140k on it . well it never had blow by b4 i did that.after i switched it it used a quart every few weeks! u may not want to take a chance like i did ...
Link to comment
Share on other sites

I had a teacher at my school run oil for 80,000 miles. He changed the filter every 6000 miles and added the necessary oil. Every other oil filter he had an oil analysis done and the oil was still good even at his 80000 miles. He is an engineer and wanted to see how long the oil was good for pretty wild stuff.
Link to comment
Share on other sites

Guest racinbird

I love the syn-dino debates!! smile.gif The basic thing to remember is that the oil may not break down, but you still get dirt/debris/contamenits(sp) in the oil. The harder you drive a car the more blow by you will get, short trips around in cold weather, all bad for oils.

 

I would rather just change the oil then chance running that through the engine. Not to mention I drive the Z hard and the truck pulls the boat around all summer so, I feel that 3-4 thousand miles is about right. You will get too many different opions on this topic, just check around other forums

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...