About oil change once a year

[Boomerang]

Hi All,

Most synthetic oils wants to change once a year, even though the miles are not that much. Any reason? Is it because of the condensation issue? For eg: Amosil XL wants to change it at 6 months/10k miles.

In my case i use Amsoil XM 0W20 in Honda Odyssey at at 4700 miles, it shows 15% life in OLM. This oil is rated for 6 months / 10k miles. Can i just change the filter and go on for another 5k? Its about 5.5 months on this oil. Oil does not look dark at all. I guess OLM is tuned for dyno 5W20 oil (2010 Odyssey).

Also in my 2000 bmw Z3 2.5, i used the 5W40 Amsoil (the most expensive one). It is almost a year and i drove only 5K miles on it. The OLM on car shows lots of life left, but oil is one year old and Amsoil says life is one year for this oil. Oil still looks ok. Not dark or black.

I searched for this and could not find any clear explanation.

Thanks

 

[Kestas]

I believe the oil manufacturers use this recommendation because of condensation issues. I never consider time when changing oil -- just miles. The only exception is if I know I'm short-tripping a car, especially in the wintertime.

 

[JC1]

Why not try running the oil in the Odyssey for 7500 miles and then get a UOA to see how it holds up? Does the Odyssey have the VCM?

 

[Boomerang]

No.. it does not have VCM. No no shutting down of cylinders.

I doubt it will go up to 7500 miles before the OLM start going -ve side. Since out of warranty, i guess it should be ok. Will take another 3 months minimum to hit 7500 miles. I guess i can just change the filter (using Honda filter) and reset the OLM and go till 7500 miles and see how it goes? It runs lots of short trips.. Picking up kids from school, shopping etc within 5 mile radius.

BMW, drives 15 miles one way and 30 miles a day in total.

 

[CharlieBauer]

Time based intervals are there to cover the worst case scenarios of usage, especially colder climates and short trips.

Your usage may not fit that scenario. Being in Texas will certainly help.

The best way to figure it out is to get a UOA, which is what I did to make me comfortable when exceeding manufacturer recommendations. My short trips have an effect but in California the effect is nowhere near as bad.

On the Honda, get a UOA done when the OLM is close to zero. On the BMW, I think you can go further than a year but I wouldn't wait until the OLM is near zero to get a UOA. Maybe get the UOA when there is 30% life left (you might need to extrapolate that if the OLM turns over suddenly due to time interval).

If possible sample rather than drain.

For the UOA, make sure you get a TBN, ideally oxidation as well.

 

[SilverSnake]

Boomerang: I have posted this article before and it has been ridiculed by many on this forum as oil industry garbage and part of the big conspiracy to get us all to change our oil more frequently than necessary. I do not agree and find the article to be an excellent summary of the issues involved. I am posting the entire article since I cannot find the link on the net anymore. I hope you find it useful.

Amsoil Article: Chemical Reactions Occur in Motor Oil, Even When Not In Use
By Dan Peterson, Vice President, Technical Development, Amsoil, May 2012


http://www.1st-in-synthetics.com/Tech/Chemical_Reactions_Occur_In_Motor_Oil_Even_When_Not_In_Use.htm

 

[Boomerang]

Thanks.. will wait and when it reaches like 5%, will send it for testing.

BMW, i think i will wait till it reaches like 7500 miles and see how it goes.

Both vehicles are not burning any oil. So never had to add any oil. One is at ~74k and other at ~135k.

 

[FermeLaPorte]

I consider miles, not time.

Oil manufacturers do testing. They do know their bits. But also, they will advertise the results that benefit them on marketing.

Whatever the case, you know your cars and so you can decide what's best for them.

 

[NormanBuntz]

Originally Posted By: Boomerang
No.. it does not have VCM. No no shutting down of cylinders.

I doubt it will go up to 7500 miles before the OLM start going -ve side. Since out of warranty, i guess it should be ok. Will take another 3 months minimum to hit 7500 miles. I guess i can just change the filter (using Honda filter) and reset the OLM and go till 7500 miles and see how it goes? It runs lots of short trips.. Picking up kids from school, shopping etc within 5 mile radius.

BMW, drives 15 miles one way and 30 miles a day in total.


One thing you could do that makes sense is follow the Honda OLM for the time to change the oil, but use a Fram Ultra for two or up to three intervals. It's now rated for 20,000 miles.

 

[Graham Piccinini]

So this is a bit extreme, but... here is what happens to oil when it sits in the engine for too long, regardless of miles. Steady diet of Castrol synthetics, but for 5+ years engine was just sitting. Engine is in good condition, for a 1990s BMW at least. But oil pan and oil filter cup are filled with this gunk because the oil was just sitting there, and over time oil lost its properties. None of this is present anywhere else, but the pan and oil filter cup. Do not leave contaminated used oil in the engine for too long, change every 1, or Max 2 years.

 

[Errtt]

Wife's RX330 gets once a year oil change. She drives very little. Less than 1k on the clock a year. So I'll take it out a couple times for a freeway/highway run. Currently running synthetic. Just done an oil/filter change a little more than a month ago and the drained oil looked nearly new out of the jug.
Her previous vehicle I used conventional oil. Same driving conditions and it also looked like new draining after a year use. Had before thought of doing 2 year oil/filter change, but couldn't pull myself to doing that.
Could not tell any condensation milked the oil but never done a UOA. No milky under the fill cap.
I guess I'll continue once a year oil change for her until any visual sign says otherwise. I do 5k myself and that happens average every 2-1/2 months.

Back in the day (military) we used to drip some oil off the dipstick onto foil. Then moved a lighter flame under it.
If it smoked before it crackles the oil, all good. If it crackles before smoke, assume some condensation.
Spit in it and check again he says

 

[SilverSnake]

Originally Posted By: Vlad_the_Russian
So this is a bit extreme, but... here is what happens to oil when it sits in the engine for too long, regardless of miles. Steady diet of Castrol Edge, but for 5+ years engine was just sitting. Engine is in good condition, for a 1990s BMW at least. But oil pan and oil filter cup are filled with this gunk because the oil was just sitting there, and over time oil lost its properties. None of this is present anywhere else, but the pan and oil filter cup.


Yeah but just look at all the money the owner saved on oil changes.

 

[BrocLuno]

OK, TX weather is somewhat like Cali weather. Winters are mild and heat is the big issue. I've run premium oils in seldom driven trucks for 5 years at a whack. All fine. Never had that kind of gunk as shown above. Pulled valve covers to replace leaky gaskets, clean as a pin.

Run it as long as you are comfortable and then send a sample. You'll know. Then base your change schedule on that

 

[Ducked]

Time is a key ingredient in a good curry, but I'd bet it isn't the only key ingredient in that Russian chocolate milk shake. Something else going on there.

If I had to guess, I'd guess glycol contamination of the oil prior to being parked up.

 

[OVERKILL]

Originally Posted By: Ducked
Time is a key ingredient in a good curry, but I'd bet it isn't the only key ingredient in that Russian chocolate milk shake. Something else going on there.


I agree. I left the oil in a few SBF's for at least that long, never got that as a result.

 

[Ducked]

Originally Posted By: OVERKILL
Originally Posted By: Ducked
Time is a key ingredient in a good curry, but I'd bet it isn't the only key ingredient in that Russian chocolate milk shake. Something else going on there.


I agree. I left the oil in a few SBF's for at least that long, never got that as a result.


SBF? Tried looking it up, but closest I got was Simulated Body Fluid.

 

[OVERKILL]

Originally Posted By: Ducked
Originally Posted By: OVERKILL
Originally Posted By: Ducked
Time is a key ingredient in a good curry, but I'd bet it isn't the only key ingredient in that Russian chocolate milk shake. Something else going on there.


I agree. I left the oil in a few SBF's for at least that long, never got that as a result.


SBF? Tried looking it up, but closest I got was Simulated Body Fluid.


Small Block Ford

 

[Ducked]

Ah yes. A North American would'nt have forgotten that.

 

[OVERKILL]

Originally Posted By: Ducked
Ah yes. A North American would'nt have forgotten that.

 

[SR5]

Originally Posted By: OVERKILL
Originally Posted By: Ducked
Time is a key ingredient in a good curry, but I'd bet it isn't the only key ingredient in that Russian chocolate milk shake. Something else going on there.


I agree. I left the oil in a few SBF's for at least that long, never got that as a result.


+2 something else is also happening in those pictures if you ask me. I ran Castrol Edge 10W60 in my motorcycles, changing every 10,000 KM. Sometimes that was 6 months other times that was two years. Worked fine for me.

But I will admit, that when I rode the bike it was for sport, so long and fast rides in a hot climate. No short tripping or condensation issues.