Quest

So long as your EFI engine is in tip-top condition, with good spark plugs, strong sparks, proper timing and a functional air filter, modern EFI gasoline engines, motor oil can easily handle 5000miles OCI, or 7000kms for regular motor oil, longer if high quality syn or syn blend is being used.

Unlike carb'ed engines with mechanical sparking systems (points, or later, solid-state ignitors), EFI doesn't suffer from too much of fuel dilution. Granted, your system is on OBD-II already, computer will also monitor and adjust the idle timing for you which further helps in minimising fuel waste, and cylinder wall "washdown" due to cylinder flooding during cold start is next to nil.

3000miles OCI is only good for carb'ed cars and not suitable for modern stock EFI engines (unless you have yours stroked). Also: with ILSAC GF-4 (5 is coming sometime this year)/API SL or SM categorisation, most motor oils are no longer gp1 only (commonly referred to as "brightstock") but mostly gpII+, meaning it's highly refined GroupII base stock, sometimes with a blend of GpIII or beyond to achieve certain desirable properties). This is especially true with national brand name 5W30/5W20 where they have to be blended in order to achieve base lubricant thermal stability (resistance in boiling off).

Q.

p.s. for UOA, check out blackstone labs.

Quest

http://www.bobistheoilguy.com says $10 - $30USD.  Is there any lab doing that in Vancouver?  Don't mind to play around with the number.  

I think http://www.bobistheoilguy.com have way better inf ...
B2L2 發表於 2009-12-18 22:27

Shorter OCI isn't gonna help much for DO REMEMBER that there are additives in the oil that would require heat and pressure to bond to the moving parts (and that's why the oil industries long shy away from using the "infamous" 4-ball wear test for it does not represent the actual condition that the moving engine parts experience during operations).

Also: if you have the $$$ to do numerous UOA tests, check it out after oil change , 300kms after oil change, 1200kms after oil change, etc. and you'll see that the wear numbers (esp. iron) will start to stabilise after, say, 1200kms and will remain on that "plateau" until the tbn runs out, and/or additives depleted.

As far as colour's concerned: this is bunk (purely psychological) for oil is meant to suspend the dirt/debris and have different colour even when fresh off the bottle. To me it just means that the oil is doing it's job.

Additional reference: diesel engines are known to create a lot of soot so engine oil is responsible for carrying it away and circulate it through the filter. Oil in diesel engines get dirty in 300kms and will stay tar-black for many more thousands of kms to come.

If you want to know how your engine /engine oil is doing, do a couple of UOA with a specific brand name of oil you have been staying true to. That way, you can tell if you can still extend the oil mileage for a bit (in my case: wife's 04 camry can take the oil easily to 7000kms in both Castrol GTX, valvoline conventional or MortarMeister full syn 5W30.

Q.

Quest

Points well taken, spoonek4 and 字典仔.

Trouble is, most general public don't seem to care/know how to maintain an automobile properly, for over 90% of them neglect their cars altogether (no oil change/skipping oil change, tune up, brake, etc. even maintenance and inspection, etc.) and the rest of them tends to "overdo" it. While I would not focus on the remaining 10%, let's talk about the rest 90%, shall we?

Automobile esp. water-cooled type, requires frequent , if not long hot continuous driving in order to extend the longevity of the engine and various lubricated mechanical parts. Frequent stop-n-go driving, as well as short trips, will kill and engine (if not the other emissions components) very quickly.

Example: a friend of mine bought a used Toy paseo sometime ago, with 180,000kms on the clock but engine and emissions were in top shape (deviation around 3psi all across 4 cyls). Because he lives 0.6kms from where he works, he resort to doing frequent short trips on a daily basis and basically killed the cat and the engine in 3 yrs time afterwards. (BTW: this friend of mine works as a teacher in Killarney).

For some, it's a necessity to drive short distances due to health reasons but for others: it's better to cover longer distances or combined several short trips into 1 major one. Not only will you save on gas due to minimisation of cold starts, but also makes your engine runs longer also.

I'm glad to be among some good technical friends here to share my knowledge (incl. spoonek4 and 字典仔 and derek) so long as you don't mind me old man ranting...

Q. :drive: