Article-- The adage that you should change your car's oil every 3,000 miles, or 4,800 kilometres, is outdated, and even 5,000 miles may be too often.

Nissan Mentioned

http://www.ctv.ca/servlet/ArticleNews/story/CTVNews/20070322/automakers_oilchanges_070322/20070322?hub=SciTech

 

Alot of people in here know this, but most people just have it beat into their brain-EVERY 3000 mi. Quick Change centers and Big Oil won't like this much.
Good to see this.

 

well the manual for the 4th gen ( i have a 97) states every 6000 Kms for engine oil and filter changes, but the car is old so i do it every 5000 Kms

 

That is overkill and a waste of money. The VQ has an aluminum block and is not a sludge monster.

The car being old has nothing to do with requiring more frequent oil changes.

 

but arent most conventional oil filters only good for about 3k?

 

Inexpensive filters are made from cheap components and have limited filtering capacity. These filters should probably be changed every 3,000 miles or so. Premium filters such as Wix, Pure-One, etc can be used for the full length of the OEM's recommended oil change interval. Super premium filters such as the AMSOIL Ea filters are more efficient; they have higher capacity; and they can be used for even longer periods.

 

What bout the Nissan oil filters?

 

The Nissan filter would fall under the premium category and would be good for 5k-7.5k miles.

 

MY 91 Honda had 12000 km oil change intervals recommend in the manual. I chicken out and changed it every 6 though..

 

You must like to waste money.

 

This article is for new cars. What's the relation to ours?

Not that I'm debating that 3k is too little with a good oil and filter, but....

 

The VQ is still very much a modern engine and not a sludge bucket. You could safely follow the current recommendations for a VQ35.

 

which Nissan filter are you referring to? Some of Nissan's filters have been opened up and they're just as bad as the low quality FRAM filters.

 

Modern in what sense? People say that a lot, but they're usually referring to power, power delivery, weight, size, smoothness, and finishing of certain internals. I take it you know some other things about its design that make it particularly kind on oil? I'd like to hear them, because the VQ35 is not a particularly low-wear engine, doesn't have a very big sump, and does have an above-average tendency to burn oil.

 

All 2008 Fords are now 7k oil change intervals.

 

I use Mobil 1 oil and Mobil 1 filters and change the oil every 4,000 miles. For the cost of oil, the peace of mind is worth it.

 

You could surely go longer than 4000 on that combo..

 

You should be doubling that change interval...

 

I must add that 4000 miles on Mobil1 oil is a total waste of monies... Why such a waste?

 

Mobil 1 filter and German Castrol fully synthetic....what do you guys think, probably 8-10k? This is the setup i put in about 2k ago.

 

That sounds good...

 

GC, 8k should be good, M1 can go longer

 

How's that? I thought GC was way more stable...

 

It's almost impossible to say what is too long or too short for oil change intervals without performing oil analyses (with TBN) on at least 2 OCIs so as to calibrate things. and you really need to stick with the same oil to be accurate about it. only then will you know if your oil will go 5k, 6k, or 10k+. it depends on many things, most notably your driving style/conditions and the health of the engine. and only oil analysis will tell you how your situation/habits are affecting the oil's service life.

here's an interesting case -- I have an '01 mercedes S500 with the sophisticated MB FSS oil life computer. the FSS always tells me the oil will go about 12k miles. but multiple oil analyses confirm that 8k is about the most I can get out of Mobil 1 0W40. by that time the additives are almost completely depleted (I believe I have a PCV issue that the car's computer doesn't know about). Lesson -- don't push OCIs out too long without confirming the oil's performance with oil analysis, even if you're using the most expensive synthetic on the market.

another case -- GC in my fiancee's 99 Accord will only go ~5-6k miles. she is a leadfoot that drives 100% stop/go city driving in chicago, and it punishes the oil.

 

My dad is convinced my accord engine is going to blow because I change it every 5k. Mobil1 Synthetic? I could probably go for 10k.

 

what other indicators besides oil analysis can tell me how long the oil life span is in my engine ? (using castrol GTX 5 or 10 w - 30 depending on the season)

 

Easily...older people are the worst ones to try and convince

 

a quick, easy & free test is to put a few drops of hot oil from the dipstick onto an old business card or 3X5 card stock and let it soak in for a couple days. the resulting "oil blotter" pattern will give you an indication of the oil's condition.

reading these blotter patterns is quite subjective, however, so I would not substitute them for the numerical results of oil analysis. and oil blotters don't tell you how much wear metal is in your oil, fuel dilution, etc etc. I use blotters as an indication of when to pull an oil sample for analysis.

you can also buy actual oil blotter test strips (called acustrip) from a company online. but for my purposes an old business card works just fine.

here's a few blotter patterns from my cars:

1) 4800 miles on GC 0W30 in my 1999 VQ. I did not get a TBN on this oil, but I can tell you it was still good for another 1-2k miles or so, b/c the outer edge of the pattern is a smooth circle that blends in evenly with the area beyond - this tells me the dispersants in the oil are still active. the only thing that stands out is the dark center, which represents oxidation and insolubles not trapped by the filter (small particles will go right through any filter). most engines display a dark center like this, and it is not a problem so long as it is not sticky/gooey (which is a sign of sludge). the oil analysis for this oil was superb - very low wear and low insolubles. lab said to keep it in for another 3k.



2) this one is Mobil 1 0W40 w/ 7k miles from my mercedes S500. note the well defined & jagged outer edge -- this tells me the dispersants are spent and the oil can no longer keep the insolubles in suspension. not surprisingly, the TBN for this oil was 1.6 -- which basically means there is very little active detergency/dispersancy left in the oil and it should be changed soon. most experts will tell you to change your oil when TBN falls below 2. There is also a property called TAN which measures acidity, and can be used in conjunction with TBN for a more accurate indicator, but I don't think it's worth the extra 10 bucks for TAN test. TBN is good enough IMO.
The oil anlysis for this oil was stellar. almost no wear metals and very low insolubles. but the TBN was also quite low, so the oil was spent. had I left it in until 12k miles (like the car's computer said) it would've turned acidic and begun to eat away at the bearings, cylinders, etc. -- I'll not allow that in my mercedes. and the lab said to change it soon.




3) finally, 5k miles on GC on my fiancee's 99 Accord. as you can see, the outer edge is starting to show a jagged structure, and there is some internal ring structure that indicates the disperants are close to being used up. the TBN for this oil was 2.4, which is fairly low considering the mileage and the quality of the oil. I can only attribute this to hard city driving. the oil analysis for this oil was just OK - not great. and not nearly as good as it was with 4k miles on Havoline 5W30. strange that a dino oil would protect better than high end GC. perhaps the honda 2.3L engine does not like a thicker oil.

 

Whoa... Neat trick!

 

GC is awesome, i love it, and use it when i can get it, but last i saw on BITOG they still say its best out at 7-9k miles, whereas M1 can go slightly longer, the additives just dont hang around as long i think.

 

AMSOil that name makes me sick, some out of no where company claims to have the best oil in the world but I've never seen in independant test to show for it, the name even makes me cringe.

 

WoW Thanks sky jumper i did not expect such a detailed explanation, but thats always welcome with me.

i will do this soon seeing how i am coming up on an oil change within the next 2000 KM

 

Ah okay. Interesting.

 

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