Are 1 year OCIs necessary with synthetic ?

[Corvette Owner]

Are one-year oil changes really necessary with synthetic oil?

I understand why they put a "time limit" on your oil change. If you did all 1 mile trips, you would not get the oil hot enough to burn off moisture in it. But, if your driving is not this extreme and includes enough, regular, long highway driving, why change at one-year? Also, I fail to see how oil just sitting in an oil pan is bad for it, it sits in a bottle.

I get occasional used oil analysis done on my 1998 Corvette. I usually change out at 0% left on Oil Life Monitor (OLM), which is around 6,000-6,500 miles (this is conservative as GM in later years increased top OLM oil life from 10,000 miles to 15,000 miles) and my lowest TBN has been 2.5 with up to 16 months.

I use a 7500 mile OCI with Mobil 1 on all my other cars, regardless of time. I have over 100,000 miles on 2 of my other 3 cars with NO oil related problems. Some of those oil change intervals have approached 2 years.

 

[tig1]

Looks as though you are doing well with your OCI. I do 10,000 mile OCIs but in a shorter amount of time and that has worked great for me.

 

[Captain_Klink]

so long as the last trip was long off enough to drive off any condensation, should be fine. u just don't want any water contaminating the oil and getting acidic. even dino can go much longer if same rule is followed.

 

[JHZR2]

My mother does severe service 5-block commutes, coupled with occasional 150+ mile drives, and has great success with M1 in her plymouth breeze for well over 120k.

 

[Corvette Owner]

Originally Posted By: JHZR2
My mother does severe service 5-block commutes, coupled with occasional 150+ mile drives, and has great success with M1 in her plymouth breeze for well over 120k.


What OCI does she use?

 

[steve20]

I'm about to dump 1 year old syn from the bowels of my 02 Z. It's a shame, only 2200 miles and 65% oil left left it has to go--extended warranty

Steve

 

[Corvette Owner]

Originally Posted By: steve20
I'm about to dump 1 year old syn from the bowels of my 02 Z. It's a shame, only 2200 miles and 65% oil left left it has to go--extended warranty

Steve


I feel your pain, I always have switched over to synthetic oil at the first oil change in my new cars (at 3,000 miles) and then I use their OCI while warrranty is in effect. After warranty, I use 7,500 miles regardless of time.

What oil do you use? And are you talking about a 2002 Corvette ZO6 ?

 

[JHZR2]

Originally Posted By: Corvette Owner
Originally Posted By: JHZR2
My mother does severe service 5-block commutes, coupled with occasional 150+ mile drives, and has great success with M1 in her plymouth breeze for well over 120k.


What OCI does she use?


7500-10k mile OCIs, which go over calendar years. Ditto on their minivan, which is in reality highway only, but does 12-15k OCIs over calendar years. Ditto on my saab, which does 12-15k mile OCIs over calendar years, but again is highway only.

 

[steve20]

yeah the 02Z 06
I like the Amsoil full synthetic 5-30 and just the plain ole AC Delco PF 46 filter. (since it sits so often in the garage, I don't even want to think about oil flow problems)
Next year will be Pennzoil Platinum 5w30, as I have about 50 quarts of it in stock


Steve

 

[Patman]

Ever since my mom bought her 2001 VW Golf in the summer of 2004 I've been doing 2 year OCIs on it, typical mileage for 2 years was around 7000 to 7500 miles. The used oil analysis with GC 0w30 have been excellent, showing that the one year rule isn't absolutely necessary. She did a lot of short trips too.

 

[djlinux64]

The greatest problem with oils is their ability to neutralize acids and blowby that are solvated in the supernatant and slowly eat away at the metal parts once the buffer in the oil runs out. That is why if you drive your car a little bit you should not let the oil just "sit there" for extended periods of time. For example, just before you store an engine for weeks/months/years, you always drop in fresh oil for this reason.

 

[JHZR2]

however, if you use a quality, high TBN oil, and verify by UOA extended buffering capacity, I am not convinced that it is an issue.