Full synthetic change interval for low use vehicles

[DeltaWing]

How long does Mobil 1 full synthetic really last in a car if the car is only driven about 1000 miles in a year? Mobil1's website is claiming 1 yr intervals for oil changes or 20,000 miles. I could understand changing the oil around 20,000 miles but if the car is only driven for a 1,000 miles a year, isn't it just a waste to change it every 1,000 miles?

I'm hoping an oil engineer can answer this question explaining the chemical reactions that occur as the oil breaks down. The Mobil1 website says the oil has a shelf life of 5 yrs. If this is so, I don't see chemically why the oil needs to be changed as often as yearly for a 1,000 mile/yr duty cycle.

 

[Warstud]

IMO...The only reason to use a Syn Oil is to use it on a daily driver for a longer OCI or very cold climates. In your case use a cheap conventional oil.

 

[Quattro Pete]

Welcome to my world... FCA tells me to change oil (synthetic) every 6 months or 6K miles, regardless which comes first. The car sits in the garage during winter, so I'll probably have less than 200 miles on the oil come next oil change. Gotta pay to play, I guess.

 

[Triple_Se7en]

Originally Posted by DeltaWing
How long does Mobil 1 full synthetic really last in a car if the car is only driven about 1000 miles in a year? Mobil1's website is claiming 1 yr intervals for oil changes or 20,000 miles. I could understand changing the oil around 20,000 miles but if the car is only driven for a 1,000 miles a year, isn't it just a waste to change it every 1,000 miles?

I'm hoping an oil engineer can answer this question explaining the chemical reactions that occur as the oil breaks down. The Mobil1 website says the oil has a shelf life of 5 yrs. If this is so, I don't see chemically why the oil needs to be changed as often as yearly for a 1,000 mile/yr duty cycle.

Welcome to BITOG
You don't mention your state location or how the vehicle is driven..... city/mix or highway. Don't mention what vehicle - what engine - what year of the vehicle.
How about giving us a little more info.
Enjoy your stay here and hope it lasts for many years.

 

[JC1]

Originally Posted by Warstud
IMO...The only reason to use a Syn Oil is to use it on a daily driver for a longer OCI or very cold climates. In your case use a cheap conventional oil.



+1. No need for more expensive synthetic IMO.

 

[y_p_w]

Originally Posted by Quattro Pete
Welcome to my world... FCA tells me to change oil (synthetic) every 6 months or 6K miles, regardless which comes first. The car sits in the garage during winter, so I'll probably have less than 200 miles on the oil come next oil change. Gotta pay to play, I guess.

And of course as a new vehicle it could have been sitting on a lot for months but they typically recommend time limits based on the date it was delivered to the buyer.

 

[y_p_w]

Originally Posted by Warstud
IMO...The only reason to use a Syn Oil is to use it on a daily driver for a longer OCI or very cold climates. In your case use a cheap conventional oil.

Depends on the car. A lot of cars these days have manufacturer's recommendations for 0W-20 or some standard like dexos. Also - the definition of "synthetic", "semi-synthetic", and "conventional" are really convoluted since oil standards have changed and because "conventional" motor oil may require Group II and some Group III base oil in order to meet the latest requirements.

 

[GZRider]

If you are have the new car warranty or power-train warranty still in effect then you probably want to change the oil at the longest allowed OCI in the manual. If you are out of warranty, there is nothing wrong with leaving Mobil1 in for 2-3 years if you only drive 1000 miles a year, unless the car has coolant loss or severe fuel dilution or something like that. Then you would still want to change it annually even with the low miles.

 

[69GTX]

There's really no reason a 1,000 mile per year car can't go 3-5 yrs on the same quality synthetic oil coupled with a quality synthetic filter claiming 15K-20K mile life. Rust would be the biggest issue on the filter housing. I'm in the same boat with 1,000 miles per year. UOA's done on such cars after 2-5 yrs consistently show nice results, with high TBN's, and plenty of oil life left. Yet, the mfg's are stuck on 1 yr max due to liabilities and the fact that they can't monitor how you put those 1,000 miles on the car. If you drive to the grocery store every day for a 3 mile round trip. That needs a minimum of an annual oil change imo....or a UOA to prove it's safe to go 1 yr or beyond. But if you drive the car 15-20 miles or more on every trip....that quality synthetic oil will last years. On the flip side, the oil only costs me $15 for Mobil 1....so why not just change it every year and be 100% safe?

 

[Audios]

Id say 2 years safely, if youre worried, try an analysis after a year and see what its showing. My M cars only see about 1000-1500 miles per year, I have been changing it yearly, but considering a longer interval if this run comes back OK.

 

[y_p_w]

I'd be curious how oil-life monitors have treated this in low-use vehicles. I believe that most motor oils handle short trips better, and electronic engine management means there aren't as many issues with fuel dilution or condensation like there used to bel

 

[Quattro Pete]

Originally Posted by y_p_w
I'd be curious how oil-life monitors have treated this in low-use vehicles.
There is typically a standard time limit on many OLMs that triggers after 1 year, regardless of miles.

 

[LazyDog]

On a normal engine with out VVT/ Variable Valve Timing that works out of oil pressure, clean oil leads to a happy engine.

What about timing chains, some engines are real picky here too GM 3.6 and 4.2L.

I would just change it yaerly and be done!

 

[Quattro Pete]

Originally Posted by Audios
Id say 2 years safely, if youre worried, try an analysis after a year and see what its showing. My M cars only see about 1000-1500 miles per year, I have been changing it yearly, but considering a longer interval if this run comes back OK.
On that point, I did a UOA on my short tripping 530i once after 1.5 years (2 winters), and did not like the results - TAN was already exceeding TBN, but maybe it wasn't yet causing any harm to the engine. Metals were somewhat high, but not sure that in itself would be a condemning factor. Anyway, I decided to cut back and stick to annual oil changes after that.

 

[ecotourist]

Originally Posted by y_p_w
I'd be curious how oil-life monitors have treated this in low-use vehicles.

Originally Posted by Quattro Pete
Originally Posted by y_p_w
I'd be curious how oil-life monitors have treated this in low-use vehicles.
There is typically a standard time limit on many OLMs that triggers after 1 year, regardless of miles.

The oil monitor for my BMW recommends very long intervals. When I was driving it reasonable amounts, the shop foreman at the dealership suggested doing an oil change half way through the interval without touching the monitor. That keeps the engine nice and clean and at the same time keeps an appropriate track of other maintenance requirements.

I now put low miles on my 2000 BMW so I change the oil several times (over a few years) before I trip the monitor.

 

[philipp10]

I just cannot understand the idea of changing perfectly fine oil because of time. Heck bring your used oil to me, I'll happily re-use it....lol. And Quattro Pete....seriously, your going to change oil after sitting in the garage and at 200 miles? The car manufacturers are way out of line on this....

 

[Quattro Pete]

Originally Posted by ecotourist
The oil monitor for my BMW recommends very long intervals.
Your car and mine use the old total fuel consumption based OLM. In my 530i, it is programmed to burn through 2375 liters of fuel before it triggers. Depending on how you drive and what fuel economy you achieve, this could mean as much as 20,000 miles between oil changes, sometimes.

The OLM in newer BMWs is limited to 10K miles / 1 year max, IIRC.

 

[Quattro Pete]

Originally Posted by philipp10
And Quattro Pete....seriously, your going to change oil after sitting in the garage and at 200 miles?
I am, while the car is still under warranty.

 

[69GTX]

Originally Posted by Quattro Pete
Originally Posted by Audios
Id say 2 years safely, if youre worried, try an analysis after a year and see what its showing. My M cars only see about 1000-1500 miles per year, I have been changing it yearly, but considering a longer interval if this run comes back OK.
On that point, I did a UOA on my short tripping 530i once after 1.5 years (2 winters), and did not like the results - TAN was already exceeding TBN, but maybe it wasn't yet causing any harm to the engine. Metals were somewhat high, but not sure that in itself would be a condemning factor. Anyway, I decided to cut back and stick to annual oil changes after that.


For short trippers....yes, change it at least annually. For those of us that don't short trip ever on their 1000 mi/yr "toys" or back up cars, a longer interval is probably fine. My car never goes back into the garage on any single trip until logging 15 consecutive miles.

 

[s2krunner]

My Ford Ranger only sees 500 miles a month but ton ton of short trips. Im changing that every 6 momths.

I just sent out my old oil thats 2000 miles & 5 months over winter. I will post on UOA section when it comes back!