How often must I change my cars synthetic oil if I drive only 5000 miles a year?

Question

I am confused as to how often I should change my synthetic car oil since I only drive 5000 miles a year or less. Does this mean I can change the synthetic only once a year because of the low mileage, or does synthetic oil break down with time, even if it has only been driven 3000 to 5000 per year? Any tips would be helpful here because not even a service dealer will give me a straight answer on this. Help! I want to keep my 1999 Toyota with 32000 miles on running for many more years!! I can't afford a new one yet!!....So, under the circumstances above..just how often SHOULD I change my synthetic oil? Thanks for your help here. I really appreciate your views.

Answer 1

This is a gray zone.  The oil companies say

"3000 miles or 3 months".  But what if I only have 100 miles on my classic cobra every 3 months?

On Mobil1 website (or was it Valvoline website...) they say that old classic cars not driven much should still get AT LEAST 1 oil change per year.

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I am in your shoe.  And I don't drive that much. And given the synthetic oil have much better oil additive to stabilize them I only change them once a year.

But the reality is that I should really change it AT LEAST once 6 months - because dirty oil (even with few thousand miles) get acidic and can cause the engine parts to rust / corrode.

This is one of my few dirty secret.  I know better and yet...

good luck....

P.S.  Synthetic oil is basically very pure oil.  And the major difference is that they DON'T break down (not due to time nor from temp).  Actually it is the impurities in conventional oil that breaks down.   But they still get dirty and the "blow by" makes them acidic over time.  That is the ONLY reason why then can't be filtered and used forever.  And even with better pH stabilizers added, they will eventually cause the engine to corrode if not changed out.

Answer 2

Considering your low operating costs due to extremely low mileage, I'd change it every six months. Could be considered excessive, but if it's not stored in a controlled environment, you may have some moisture problems. Cheap insurance.

Answer 3

It is personal perferance.  I would change it once a year along with oil filter.  I used to change it twice a year but does not have enough mileage on it, so once a year is good.  I am using Mobil 1.

Answer 4

I`m sure you`re fine with changing it once a year with that low of mileage...Probably also with regular oil too as ..well read this, and check out the link below too!

Advantages of Synthetic

Synthetic oil was originally developed for high performance racing engines. Mobil tried to popularize synthetic oil for passenger vehicles back in the early 1970's. At the time, Mobil was promoting 20K or 25K oil changes with synthetic, but they soon backed down from this. Synthetic oil is a good choice if you have a vehicle with a high performance engine (in fact synthetic is required for many of these engines). It is also a good choice if your vehicle is operated in extremely cold climates. It has higher resistance to breakdown caused by heat and it flows better in extreme cold. Unfortunately for the synthetic oil industry there is virtually no advantage to using synthetic oil in a non-high performance engine that is operated in moderate climates. You probably could go a bit longer between oil changes with a synthetic, i.e. following the normal service schedule even if you fall into the severe service category, but I wouldn't advise this. In short, synthetic may give you the peace of mind of knowing that you are using an oil that is far better than necessary for your vehicle, but it won't reduce wear or extend the life of the engine. The mistake some people make it to wrongly extrapolate these benefits onto normal engines operated in mild climates, with the ultimate lack of any knowledge being manifested with statements such as "synthetics provide 'Peace of Mind,' or 'Cheap Insurance,'" or other such nonsense.

Extended Change Intervals

Most manufacturers of synthetic oil advise users to not exceed the manufacturer's recommended oil change interval. Part of this is self interest (they don't want to be liable for any damage) but the real reason is that synthetic oil, while it does have certain advantages, still becomes contaminated.

Be extremely wary of synthetic oil companies that offer to pay for your repairs if it is determined that their oil and their extended change interval recommendation caused the problem. Think for a moment of the incredible hassle you would have to go through to prove responsibility for an engine problem. Who would pay your legal bills? Who would pay for replacement transportation during the battle? The more bizarre the warranty the poorer the product is a good rule of thumb.

API Certification, Phosphorus & ZDDP

Never use a non-API certified synthetic oil (there are many of these on the market). The problem with the non-API certified synthetics is that they contain too much phosphorus (in the form of the additive ZDDP (Zinc Dialkyl Dithiophosphates)). The API has limited the amount of phosphorus because phosphorus shortens the life of the catalytic converter. These oils are fine for snowmobiles, motorcycles, and older cars that don't have a catalytic converter, and the extra ZDDP does provide additional wear protection. Unfortunately, the marketers of some the non-certified oils do not explicitly and honestly state the reason for the lack of API certification. You can check the status of API certification on the API web site. Be certain to go not just by the manufacturer name but by the actual product as well. This is because a manufacturer will sometimes have both certified and non-certified products. Suffice it to say that Mobil 1, Royal Purple, Castrol, & Havoline all make synthetic oils that are API certified and that can be purchased at auto parts stores and other retail outlets. Amsoil has one product line, XL-7500 that is API certified, but it's other lines contain too much ZDDP to be certified and should not be used in vehicles with catalytic converters.

Answer 5

i use synthetic oil,and i only change mine once year,that's all you need to change it if you don't drive over 5 k a year,i only use my one truck once in a great while so by using synthetic oil in it i only have to change about once a year,you can drive up to 8 thousand miles on synthetic oil and not harm a thing,it was made to go the distance,i use mobil one ,and have never had any problems from it as of yet,good luck.