Should synthetic be changed after one year regardless of mileage?

[kosoku]

Hi all, I'm sure this has been asked before but I'm on my mobile and the search didn't find any relevant results. I have two cars that are weekend cruise / occasional autocross or drag race use and I use full synthetic in both. I put maybe 3,000 miles on the cars each year. Would the additives break down after a year requiring that I change the oil? I normally do 5,000-8,000 mile intervals on my daily drivers. I keep seeing Amsoil and others advertise oils as good for a gazillion miles or one year, whichever comes first.

 

[Bamaro]

No!

 

[zrxkawboy]

After 1 year, I'd do a UOA on each of them. Anything else is just guessing. If they have plenty of life left in the oil, then go 1.5-2 years. There's a lot of variation in "full synthetic" oils, and some engines are much harder on oil than others. You really need to get the UOA done to know where you're at.

 

[JHZR2]

One year is pretty old and obsolete as a generic rule of thumb. Two years IMO is a good rule of thumb. UOA is an important element of the whole story, as some engines can be very easy on oils, while high fuel, diluters might be prudent to do once a year or sooner.

 

[D1dad]

I do but I'm ocd on oil changes. I have a 2000 super duty that I bought new, 174k on a 7.3. I rarely ever put 3k a year on it anymore and it breaks my heart to watch 15 quarts of synthetic blend drain out of that thing every November. I really should sell the truck as I don't need it, but I can't bring myself to do it.

 

[SVTCobra]

https://www.bobistheoilguy.com/foru...-with-filter-pics-and-magnet#Post5064889 UOA of my pickup with 12k miles and 20 months of time. Used full synthetic oil and results are okay. I have had longer time intervals than that, so I'd say run it till you hit your mileage.

 

[Bluestream]

My BMW is pushing 4 years on T6 5W40 with about 1500KM use. Motor oil changes are usually scheduled based on the time in service or the distance that the vehicle has traveled. These are rough indications of the real factors that control when an oil change is appropriate, which include how long the oil has been run at elevated temperatures, how many heating cycles the engine has been through, and how hard the engine has worked. The vehicle distance is intended to estimate the time at high temperature, while the time in service is supposed to correlate with the number of vehicle trips and capture the number of heating cycles. Oil does not degrade significantly just sitting in a cold engine. On the other hand, if a car is driven just for very short distances, the oil is not allowed to fully heat-up, and contaminants such as water accumulates in the oil, due to lack of sufficient heat to boil off the water. Oil of this nature, just sitting in an engine, can cause problems.

 

[CT8]

Originally Posted by zrxkawboy

After 1 year, I'd do a UOA on each of them. Anything else is just guessing. If they have plenty of life left in the oil, then go 1.5-2 years. There's a lot of variation in "full synthetic" oils, and some engines are much harder on oil than others. You really need to get the UOA done to know where you're at.

You would spend the $$$ for a uoa instead of changing the oil?

 

[Triple_Se7en]

You can go two years, provided you are not idling long spells and drive a TGDI / GDI. Be wary of fuel dilution. Also, your location offers more stable temps overall, versus-that of living in the Midwest or Northern Plains.

 

[ka9mnx]

Originally Posted by CT8

You would spend the $$$ for a uoa instead of changing the oil?

Yea, what's with that? Normally I would say NO but since you occasionally autocross and drag race I would have to say YES. I can go several years without oil changes but I rarely do over 2k on each vehicle.

 

[Gebo]

I only go 1 year on an oil. My Mom's car goes about 1k/year but it still gets fresh oil every April. Church van gets about 3k/year but it gets fresh oil every April. Am I lacking brain cells? Yeah, probably from those "extra" oil changes I do without gloves. At this point in my life, I can afford an extra $50/year/car for an oil change. Heck, I run synthetic in my mowers and change their oil every spring. I know, stupid is as stupid does....

 

[ARB1977]

My mother in law has a 95 bmw with 17K miles that sits. Who knows when the last oil change was done. Last time I chaecked it it was brand new looking.

 

[zrxkawboy]

Originally Posted by CT8

You would spend the $$$ for a uoa instead of changing the oil?

Yes. If you establish a safe OCI (for example, 2 years, let's say), you can continue to do that without paying for a UOA each time. If you just blindly change the oil each year, all those extra changes using synthetic oil could be expensive (especially if the OP uses boutique oil). IOW, a one- or two-time expense to establish a good OCI vs an ongoing and likely unnecessary expense.

 

[demarpaint]

Originally Posted by JHZR2

One year is pretty old and obsolete as a generic rule of thumb. Two years IMO is a good rule of thumb. UOA is an important element of the whole story, as some engines can be very easy on oils, while high fuel, diluters might be prudent to do once a year or sooner.

Exactly. And avoid blanket statements like Dino oil can go x miles/years, and Synthetic oil can go x+y miles/years. Run your oil a year, extract some oil from the dipstick tube and send it off for analysis, base your OCI on that.

 

[spk2000]

When was the last time you saw a car engine destroyed by changing the oil a little late. Only time I see them destroyed is running out of oil. Oil doesn't just go bad that fast siting in an engine but it can help if it's garage stored and not subject to hot and cold climate changes.

 

[Pinoak]

Originally Posted by Gebo

I only go 1 year on an oil. My Mom's car goes about 1k/year but it still gets fresh oil every April. Church van gets about 3k/year but it gets fresh oil every April. Am I lacking brain cells? Yeah, probably from those "extra" oil changes I do without gloves. At this point in my life, I can afford an extra $50/year/car for an oil change. Heck, I run synthetic in my mowers and change their oil every spring. I know, stupid is as stupid does....

Most important is your taking care of these vehicles and machines. In the end, if y'all keep your vehicles and machines for the duration of their lives, it easily adds up in your favor do to longevity and less mechanical issues. It might be good oil your dumping but with such little miles of use in the vehicles I assume the miles are accumulations of many short trips. In that case the oil might be highly spiked with fuel by the time you change it, therefore it would be necessary. The only way to know for sure is to run uoas. That would probably be as much or more than the cost of oil change anyway.

 

[alarmguy]

Originally Posted by kosoku

Hi all, I'm sure this has been asked before but I'm on my mobile and the search didn't find any relevant results. I have two cars that are weekend cruise / occasional autocross or drag race use and I use full synthetic in both. I put maybe 3,000 miles on the cars each year. Would the additives break down after a year requiring that I change the oil? I normally do 5,000-8,000 mile intervals on my daily drivers. I keep seeing Amsoil and others advertise oils as good for a gazillion miles or one year, whichever comes first.

Im not sure why you wouldnt change the oil. Whether or not additives break down, which I doubt they would in just one year. I dont understand the big deal of changing the oil.

 

[NO2]

If your car warranty requires annual changes I would do so. Otherwise just wait until you've reached your mileage or follow the OLM .

 

[Hall]

Originally Posted by zrxkawboy

Originally Posted by CT8

You would spend the $$$ for a uoa instead of changing the oil?

Yes. If you establish a safe OCI (for example, 2 years, let's say), you can continue to do that without paying for a UOA each time. If you just blindly change the oil each year, all those extra changes using synthetic oil could be expensive (especially if the OP uses boutique oil). IOW, a one- or two-time expense to establish a good OCI vs an ongoing and likely unnecessary expense.

By your logic, one can do 1-2 oil analyses to determine their interval, but for how long ? Conditions change - engine wear, oil formulation, and so on. If you're going to spend $25-30 to analyze the oil, that's just silly. Spend that same money and just change the oil !

 

[demarpaint]

Originally Posted by hallstevenson

Originally Posted by zrxkawboy

Originally Posted by CT8

You would spend the $$$ for a uoa instead of changing the oil?

Yes. If you establish a safe OCI (for example, 2 years, let's say), you can continue to do that without paying for a UOA each time. If you just blindly change the oil each year, all those extra changes using synthetic oil could be expensive (especially if the OP uses boutique oil). IOW, a one- or two-time expense to establish a good OCI vs an ongoing and likely unnecessary expense.

By your logic, one can do 1-2 oil analyses to determine their interval, but for how long ? Conditions change - engine wear, oil formulation, and so on. If you're going to spend $25-30 to analyze the oil, that's just silly. Spend that same money and just change the oil !

You bring up a good point, and that was my logic until I was able to buy Wix oil analysis kits for under $10, TBN included. Now it is a little higher but well below $25. Anyway my driving conditions remain the same so the data has proven to be cost effective and useful.