Engine Oil : Conventional VS Full Synthetic for a car driven for short distances

[Chung Myung]

Which would be the better option for a Toyota Corolla 141 (2008) that has been driven using exclusively conventional engine oil by the previous owner?

The mileage is 64,XXX kms, purchased from the owner who bought it brand new so the mileage is accurate.

Max distance the new owner would be driving is 250-300Kms a month, that too short distances.

What would be the better option for the new owner, continue using conventional oil ( Castrol 10W30) and change it every 6 months or switch to full synthetic (Mobil 5W30) and change it every 12 months? (As the car won't be driven 5000kms even in an year)

The new owner prefers to use synthetic because the car is very noticeably quieter when accelerating with synthetic oil compared to conventional but wonders if it's pointless and if it could even be detrimental compared to using conventional oil because of the longer service interval.

Thank you in advance.

Edited December 12, 2024 by Chung Myung

[iRage]

8 hours ago, Chung Myung said:

Which would be the better option for a Toyota Corolla 141 (2008) that has been driven using exclusively conventional engine oil by the previous owner?

The mileage is 64,XXX kms, purchased from the owner who bought it brand new so the mileage is accurate.

Max distance the new owner would be driving is 250-300Kms a month, that too short distances.

What would be the better option for the new owner, continue using conventional oil ( Castrol 10W30) and change it every 6 months or switch to full synthetic (Mobil 5W30) and change it every 12 months? (As the car won't be driven 5000kms even in an year)

The new owner prefers to use synthetic because the car is very noticeably quieter when accelerating with synthetic oil compared to conventional but wonders if it's pointless and if it could even be detrimental compared to using conventional oil because of the longer service interval.

Thank you in advance.

Okay...so...the viscosity of the oil and the frequency of change would depend more on the condition of the car and your usage and the conditions the car is being used in.

Although you don't rack up (and the car hasn't racked up) that many miles it still constitutes as "harsh" use according to the manufacturer's guidelines. It is because the car is mostly left parked and most of the rides can potentially be short rides (which doesn't give much time for the engine to bring the oil up to optimal operating temperature).

Now..here is the subjective part and if you talk to 10 different people you will get 20 different opinions.

Viscosity: What is the condition of your engine ? Do you have a loss in compression, engine running rough ? These factors will influence one to go to a higher or lower viscosity. 

If 10W30 seem to be okay for the car this far,I would say keep using it. See how the car acts with it and later decide if you want to change the viscosity.

Mineral vs Synthetic: Remember...a good mineral oil is better than a cheap off branded synthetic oil. So keeping that in mind and you do get the usual reputed synthetics..

Synthetic oils tend to hold its composition better than mineral oils. For example, a synthetic oil might hold its composition far better than a mineral oil when driving long distances in high-heat environments, thus absorbing engine heat and lubricating better (for longer) than a mineral oil would. Similarly a synthetic oil would be better at tolerating rapidly changing operating conditions as well (like weather). Considering you won't be using the car that much, and the car will possibly be driven short distances, I would say you should consider synthetic (or very least a semi-synthetic) oil. If you leave the car parked for a long period of time it would far resilient to breaking down and even in short runs a synthetic oil would be able to absorb heat and lubricate far better and lower op-temps than a mineral oil (usually). Can a mineral oil do (the latter) the same ? Well, yes, the high-grade ones are as expensive as synthetic oils. As for not breaking down easily...well...I would say the synthetics still have an edge here (making a mineral oil have the same property is pretty much making a synthetic oil). You don't get such high-grade oils in the market anymore as they once used to because you might as well go buy a synthetic.

So....perhaps 10W30 Synthetic would be the way to go if you are open to extending your service cycle. I wouldn't necessarily recommend 12 months but at least look at something in between. 

I think the near 12-month synthetic vs. near 6-month mineral choice may be dictated by cost as well (?). There is nothing wrong with a good mineral oil and regular oil changes (just that the synthetic may offer a slight benefit as mentioned above). I don't know how eco conscious you are but you may even take in to account the impact of frequent oil disposals as well.

 

[Chung Myung]

 

Thank you for the detailed reply 🙏

 

35 minutes ago, iRage said:

Okay...so...the viscosity of the oil and the frequency of change would depend more on the condition of the car and your usage and the conditions the car is being used in.

Although you don't rack up (and the car hasn't racked up) that many miles it still constitutes as "harsh" use according to the manufacturer's guidelines. It is because the car is mostly left parked and most of the rides can potentially be short rides (which doesn't give much time for the engine to bring the oil up to optimal operating temperature).

Now..here is the subjective part and if you talk to 10 different people you will get 20 different opinions.

Viscosity: What is the condition of your engine ? Do you have a loss in compression, engine running rough ? These factors will influence one to go to a higher or lower viscosity.

 

No, as far as I can see/hear the engine runs smooth. Previous owner reported no oil burn.

There was a slight ticking noise (lifters? valves?) when accelerating between 2000-3000RPM (previous owner hadn't even noticed so the sound could've been there since the car was brand new) which went away after the first oil change done by the new owner with Mobil 1 Advanced Full Synthetic 5W30.

 

40 minutes ago, iRage said:

Mineral vs Synthetic: Remember...a good mineral oil is better than a cheap off branded synthetic oil. So keeping that in mind and you do get the usual reputed synthetics..

 

Yes, going forward it'd be either Mobil or Liqui Moly (if went the synthetic route), purchased directly from the authorized agent (McLarens or Semini Motors)

 

44 minutes ago, iRage said:

So....perhaps 10W30 Synthetic would be the way to go if you are open to extending your service cycle. I wouldn't necessarily recommend 12 months but at least look at something in between. 

I think the near 12-month synthetic vs. near 6-month mineral choice may be dictated by cost as well (?). There is nothing wrong with a good mineral oil and regular oil changes (just that the synthetic may offer a slight benefit as mentioned above). I don't know how eco conscious you are but you may even take in to account the impact of frequent oil disposals as well.

 

 

The cost is about the same if oil gets changed twice a year with conventional oil or once a year with synthetic.

 

48 minutes ago, iRage said:

I don't know how eco conscious you are but you may even take in to account the impact of frequent oil disposals as well.

 

 

Well let's just say if it is a choice between engine longevity and environmental conservation the clear choice would be the first 😅

But I reckon squeezing as many kms as possible from an engine helps the environment too considering the environmental impact of manufacturing new engines 😁

[iRage]

Hope the car gives you many miles of smiles

You should start a thread about your car with pictures. We love seeing pictures of cars no matter what it is and hearing about the owner's life with the car <despite what many think..car enthusiasm is as much about the people as it is about the car).

Sounds like you got a clean E140 considering the owner knew what was going on...

Being a 2008 is it an export model built in Japan or was it after the time production was shifted to Thailand ?

[Chung Myung]

1 minute ago, iRage said:

Hope the car gives you many miles of smiles

You should start a thread about your car with pictures. We love seeing pictures of cars no matter what it is and hearing about the owner's life with the car <despite what many think..car enthusiasm is as much about the people as it is about the car).

Sounds like you got a clean E140 considering the owner knew what was going on...

Being a 2008 is it an export model built in Japan or was it after the time production was shifted to Thailand ?

It's not mine actually, it's my brother's but I'll post a few pictures if he's okay with it 👍

So... the best recommendation would be synthetic oil from a reputed brand changed every 9ish months, right?

if you were the owner, would you change to 12-month synthetic 5W30 oil changes or stick with 6-month conventional 10W30 changes? ( imagine those 2 are the only options you've got and both oils are from a reputed brand )

[iRage]

30 minutes ago, Chung Myung said:

if you were the owner, would you change to 12-month synthetic 5W30 oil changes or stick with 6-month conventional 10W30 changes?

Funny you should ask....I have two cars in Japan used quite rarely. Both are on 10 month or so service cycles on average. Both cars get 6 month inspections at the dealer and depending on the findings there it is determined if the oil needs to be changed then or can wait till the next scheduled oil change appointment or inspection appointment. The older car (black) is on a mineral oil (they call it a synthetic blend but it is mineral...using for some of its characteristics) and the other is on full synthetic.

What oil to use is very subjective....assuming the car is in good shape and sticking to my current driving pattern (early morning low-traffic drives three times a week and post-rush hour drives 2 days a week and the usual run around Colombo on weekends, each weekday run is about 12km)....and cost is not an issue then I would go with a synthetic option and stick with a 8 to 10 month change.