Poll:100% Synthetic oil - change frequency

[Sam]

Only for people using 100% synthetic oil in their car engine.

I used to use Mobil-1 and change my oil every 10K. Now I use Mobil-1 Extended Performance and change it every 15K.

[yakers]

In wife's Mazda Miata use M-1, change the oil at 6K and the filter at 3K. Plan to keep the car a long time. The oil does not break down but it still gets dirty therefore the filter change. I interchange synthetic & semi-synthetic in the Ford Focus and change the oil at 5 or 6K. Need to change it for the warranty.

[FinanceDude]

I'm still not sold on synthetic, maybe you guys can help me understand.........

I know a LOT of mechanics that go with regular oil. They tell me that while synthetic DOES not break down as quickly as regular oil, it still gets dirty, and dirty oil causes problems in engines............

Plus, the synthetic oil I see is about twice as expensive as regular, so the cost would be the same whether I do regular oil every 3000 or synthetic every 6000??

Or maybe I am confused............. :P

[saluki9]

FD - You are correct, the oil still does get dirty. I just swap oil filters halfway through the cycle.

In my daily driver I use mobil one and change every 7K, on my toy / track car I change much more frequently. Because I'm usually running it pretty hard I swap out the mobil one every 3-4K

[brewer12345]

Semi-synthetic and every 7000 to 7500 miles in both cars. In my daily driver, that means an oil change every 3 months. In the minivan, its about every 9 months.

[FinanceDude]

Quote:

Originally Posted by saluki9 FD - You are correct, the oil still does get dirty. I just swap oil filters halfway through the cycle. In my daily driver I use mobil one and change every 7K, on my toy / track car I change much more frequently. Because I'm usually running it pretty hard I swap out the mobil one every 3-4K

How much does Mobil 1 cost per quart??

I guess I'm stubborn, I've run regular oil and changed it every 3000 miles, and have enver had an engine problem.

Or maybe I'm just stubborn...........

I remember my dad's famous words: "Change your oil, or change your engine"..............

[mathjak107]

my bmw gets 1 oil change every 15.000 miles. 8 quarts extended service synthetic

[TromboneAl]

Without draining the oil, is the oil level low enough that you can swap the filter without losing a lot of oil?

[TromboneAl]

Here's a related question: I change the oil in my pickup every 6 months or so, because the oil gets old, even though it only gets driven about 1000 miles or less in that time. I wonder if I could avoid that by using a synthetic. IOW, does the synthetic age more slowly?

Related to that, I have about 18 quarts of Chevron 5W-30 that I got on sale. It will be about a year and a half before all of that gets into the car. Do you think it will have aged too much by then?

[MasterBlaster]

Quote:

Originally Posted by TromboneAl Here's a related question: I change the oil in my pickup every 6 months or so, because the oil gets old, even though it only gets driven about 1000 miles or less in that time. I wonder if I could avoid that by using a synthetic. IOW, does the synthetic age more slowly? Related to that, I have about 18 quarts of Chevron 5W-30 that I got on sale. It will be about a year and a half before all of that gets into the car. Do you think it will have aged too much by then?

From the motorhead sites.... The consensous is that you should change the oil in your car every 12 months if it's a low milage vehicle. I do exactly that for 2 of my cars.

For oil kept in the can/bottle it should stay good for a decade or more before it degrades. It's only when it gets cooked in the motor that the chemical breakdown is significant.

To answer the original topic for those that prefer synthetic versus regular oil. None of the OEM manufacturers recommend that you extend the oil change frequency when using synthetic oil. While synthetic oil has some attractive properties in that thermal breakdown is much much less, it still has to act as a chemical solvent to mop up all of the sludge. The idea then is to keep oil in the car only if it is capable of disolving those unwanted byproducts. Therefore the change interval should not be extended. The only people who make the longer change interval claims are the oil marketers not the engine manufacturers. Think about that before you extend the change interval.

The other thing that synthetic oil is used for is to accomadate engines where the engine cannot be designed to cool properly (A new Corvette or a Viper come to mind). Because the cooling in these engines is insufficient, conventional oil would begin to cook and sludge up the engine. For this reason these engines specify that synthetic oil must be used. And that, in my mind, is not really a good thing.

[Sam]

Quote:

Originally Posted by TromboneAl Here's a related question: I change the oil in my pickup every 6 months or so, because the oil gets old, even though it only gets driven about 1000 miles or less in that time. I wonder if I could avoid that by using a synthetic. IOW, does the synthetic age more slowly?

Yes.
www.jdpower.com/articles/article.aspx?ID=208

Quote:

Originally Posted by TromboneAl Without draining the oil, is the oil level low enough that you can swap the filter without losing a lot of oil?

Most oil filters are above the oil level, so you would only lose the oil in the filter itself.

Quote:

Originally Posted by yakers In wife's Mazda Miata use M-1, change the oil at 6K and the filter at 3K.

I change the filter when I change the oil.

Quote:

Originally Posted by FinanceDude Plus, the synthetic oil I see is about twice as expensive as regular, so the cost would be the same whether I do regular oil every 3000 or synthetic every 6000??

Material cost is not an issue for me. Time (and labor) is.

[runchman]

Bmw says mine is to be changed every 15,000 miles. If the factory says so, that's good enough for me - I'll take their advice over the 'expert' in the adjacent cubicle any day.

I think the (conventional oil) every-3k mile rule is overkill and a waste of resources, but that's just me.

- John

[Texas Proud]

My car has a program that calculates the life left over.... currently about 6,000 miles with 40% left to go... the first two changes were about 6,000 with 5% left..

[Sam]

Quote:

Originally Posted by Texas Proud My car has a program that calculates the life left over.... currently about 6,000 miles with 40% left to go... the first two changes were about 6,000 with 5% left..

What car is it? What kind of oil did you use?

[TromboneAl]

Thanks, Masterblaster.

Quote:

3k mile rule is overkill

Absolutely. My Echo manual says 7.5K (or 5K if used in dusty hot places), and yet the dealer always tells you "3,000 miles."

Quote:

My car has a program that calculates the life left over....

Do you mean it measures something and displays info, or just that it has a formula for calculating when to make the next change?

[lets-retire]

My Pontiac had a program in it that supposedly calculated oil usage based on idle time acceleration, etc. than told you when to change the oil. Mine worked out to about every 5k miles. Of course I got rid of that car because it was always at the dealership for warranty work.

[dumpster56]

Consumer reports did a big study on motor oils on NYC taxis.

Get this 7500 is FINE to change the oil!! The 3000 change is not in any maintenace manuel , none. Heck some autos have a 10k oil change time frame.

The 3000 oil change is a marketing tool.

[Khan]

I don't know what kind of oil they put in the car (probably regular).

Get it changed once a year, which is less than 1600 miles.

[Texas Proud]

Quote:

Originally Posted by Sam What car is it? What kind of oil did you use?

Acura TL... just some formula that keep track of how often you start the car, RPMs etc etc... don't know the whole program (heck, don't know if it is published)... but some people on the TL forum gets a message in 4 to 5K miles with lots of city driving... this is my weekend car and I usually drive more highway...

I use regular oil... what they put in at the dealership... tell you the truth, I have not asked...

[Sam]

That makes sense. Even with regular oil, 6000 miles is about right.