Do you agree with my expectations?

[The Critic]

If one looks back in our UOA archive, it is quite evident that BITOGers tend to underestimate the capabilities of the oils they use. We have a tendency to run our oils for short intervals that do not truly allow for the oil to show its capabilities.

With that said, would you folks agree with me that a good conventional oil can last 5000 miles or 6-months under severe service, and 6-mo or 7500 miles under normal service?

Would 10,000 miles or 1-yr, whichever comes first, be considered a reasonable interval with a good quality synthetic oil, such as Mobil 1, Amsoil ASL/ATM, Pennzoil Platinum, or Castrol Syntec?

Lastly, would 12,000 miles or 1-yr, whichever comes first, be reasonable for Amsoil TSO/HDD, Mobil 1 Ext. Perf, or GC?

Of course, all suggested intervals are based on the assumption that the individual has a clean engine, with no dirt or coolant ingestion issues, and is using a high-capacity filter on intervals > 10,000 miles.

Thanks in advance for the comments.

[ May 27, 2006, 10:54 PM: Message edited by: The Critic ]

 

[Tree Hugger]

I run my '03 Chevy Avalanche on the OLM (Oil Life Monitor), which we have excellent reason (the original engineers) to believe is calibrated on dyno, and with 100% safety factor.
I normally get over 9,000 miles OCI.
So yes, any modern dyno can (under the right driving conditions) easily do 10,000 miles.
Your driving conditions may vary. I have a computer monitoring mine, and SL rated dyno oil could easily do 18,000 for me...
I go by the OLM for cautions sake, but I have a WIDE safety margin.

 

[sxg6]

Better safe than sorry is the way i feel. Thats why i dont run my oil as long as possible. I dont think you can make a general statement that dino can last 5k or 6mo. I'm sure a honda civic would have no problem on conventional for 5k or 6mo with severe service, but what about a subaru impreza wrx sti or mitsubishi lancer evolution? Basically I dont think you can set standard intervals for conventional or synthetic because there are far too many factors involved in oil condition.

 

[buster]

Critic, I agree 100%. Well said.

 

[va3ux]

Only Partially Agree. Here's why :

Based on the same UOA that you've looked at, it is also quite apparent that the OCI needs to be qualified based on specific engine type, and more importantly, UOA on that engine.

Everyone would love to use these general guidelines (such as you've listed) because they take all the thinking out of the process. But they could well be disatrous for some engines and driving conditions. And they will probably work just fine for others.

For example, my brother has had Honda Civics for the past 16 years. He does 90% highway driving. His most recent Civic - he does 7500 mi OCI using the cheap dino/filter service at Costco. And he has 465,000 km (285,000 mi) on that car. If I followed that program on my Chysler 2.7L V6, it would have been trashed 100,000 mi ago. My 2.7L V6 shears a synthetic 30 down to a mid 20 weight in just 4000 mi, and depletes the TBN to the point that there's no protection left. So these "ranges" or guidelines you have suggested simply would not provide reliable service in all cases. Hence, extended OCI needs to be determined empirically (with used oil analysis) to be sure that it's safe for that engine and it's driving conditions, rather than just blindly following guidelines.

In the example above I've used 2 extremes to illustrate the point. But they're real ones and there are other similar ones. In between these extremes are plenty of engines that may do fine with your suggested guidelines, perhaps with some tweaking here and there.

Phil

 

[Curious Kid]

It would appear that one must remember to bounce the OEM's recommendations for OCI's, supplimented by trends in used oil analysis (from YOUR engine used the way YOU use it). For the most part, that means that those that have posted used oil analysis are already doing what it is they can in trying to make the best case for their equipment's lifespan through testing the remaining life of the oil, but also doing a check-up on the running conditions of individual components that come into contact with the oil - analogis to a blood test.

For those that are using an engine outside it's originally intended purposes, the OE recommendations may still serve as a starting point assuming not much other than output application changes. Otherwise, further research based upon bearing surface areas, clearences and finishes, quality of filtration, oil flow rates and temps, shear and other contaminent potential, and consideration to systems capacity, etc.

There can be a vast gray area, especially when the engine management system is greatly simplified and the operating conditions being so diverse. Ironically though, atleast during what's considered the start-up phase of an engine, a lubricant's viscosity is higher than normal and in thought, could be so different from one location to the next. Yes, it is recommended that the engine be operated with some restraint to loading until temps have equalized, but I also wonder if the system design is just giving all its got, you know? It's doing what it's designed to do, faulted by lack of consideration/material properties/knowledge because such situations weren't presented or thought relavent in it's inception, and wearing is just inevitable. FWIW - In the back of my mind I hear, "It's a consumable!"

Impermenence.

 

[bruce381]

any SM 5-7K
any SM syn 7-10K
bruce

 

[HTSS_TR]

Mobil 1 in '00 MB E430 for one year, mileage is 11k to 13k miles.

Mobil 1 in '94 Lexus LS400 for one year, mileage is 12k to 15k miles

Mobil 1 in '04 Honda S2000 for one year, mileage is 5k to 6k miles.

No engine problem related to oil. Mobil 1 is a good and not too expensive synthetic oil. I like them, but if I can but other brand names synthetic for less, I will try them.

 

[eddyzima]

TheCritic, i agree with most, but i do not think regular syntec and other groupIII synthetics are real 10k oils.

 

[Steelers]

I would go 5K with any conventional oil with confidence and 10K with any Group IV synthetic. Especially if the vehicle sees mostly highway miles. Change the fuel and air filters regularly and monitor oil for correct level if its a burner. This helps recoup the cost of the synthetic oil.

 

[charbaby]

Well, Im kinda curious about my situation. This upcoming OCI will be about 5 months and 2500 miles on both my vehicles with lots of stop & go driving and little highway use except the times when I jump onto the highway just to get to another exit(2-3 miles). Both cars are using 3qts Havoline 5w30 conventional SL/GF3 and 2qts Havoline Syn 5W30 SL GF3. Does this mean that I can still travel up to or past 3000 miles and maybe 6-7 months????