Synthetic oil or not for very low mileage auto?

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EdNorton
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Synthetic oil or not for very low mileage auto?

Post by EdNorton » Fri May 17, 2019 9:04 am

I have a 1999 Miata and doing first oil change since purchase. It now has 13,000 miles, never had synthetic oil. I'll probably drive it less than 5k miles/year. Just purchased last July.
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sunny_socal
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Re: Synthetic oil or not for very low mileage auto?

Post by sunny_socal » Fri May 17, 2019 9:25 am

Synthetic. It's a better oil, you're asking about saving $20 over a year or two? Your tires will rot out from under the car and hit your wallet a lot harder than the oil change :?

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Re: Synthetic oil or not for very low mileage auto?

Post by Smoke » Fri May 17, 2019 9:27 am

Synthetic

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Re: Synthetic oil or not for very low mileage auto?

Post by MathIsMyWayr » Fri May 17, 2019 9:35 am

When I work on cars, I always use the best parts available including engine oil, filters, belts, brake pads. Big savings on labor more than justifies material costs. The difference between regular engine oil and the best synthetic is about $10 for 5 quarts.

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Re: Synthetic oil or not for very low mileage auto?

Post by SquawkIdent » Fri May 17, 2019 9:55 am

IMHO, a no brainer synthetic.

Enjoy it! :sharebeer

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Re: Synthetic oil or not for very low mileage auto?

Post by badger42 » Fri May 17, 2019 10:02 am

Synthetic and chance once a year. It'll give better protection for an infrequently driven car, and the marginal cost is minimal.

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Re: Synthetic oil or not for very low mileage auto?

Post by j0nnyg1984 » Fri May 17, 2019 10:08 am

Always. Been running Mobil 1 5-30 since I bought my truck in 2005, CPO with 6k miles. It now has 202,xxx and runs like a top.

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Re: Synthetic oil or not for very low mileage auto?

Post by tainted-meat » Fri May 17, 2019 10:14 am

Full Synthetic > Synthetic Blend > Conventional Oil

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Re: Synthetic oil or not for very low mileage auto?

Post by Teague » Fri May 17, 2019 10:14 am

Depends on the oil, but probably won't make much difference in your application. "Conventional" oils have gotten extremely good over the years. Your application is not one of extreme heat, no turbo bolted on and no track days I'm assuming. But you would want an oil that maintains its TBN, its ability to neutralize acids, since you will probably change oil based on time rather than mileage.
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Re: Synthetic oil or not for very low mileage auto?

Post by whomever » Fri May 17, 2019 10:19 am

1)I use full synthetic oil from the first change onward. But I buy new cars and plan to keep them for many years and miles.

2)You have a 20 year old car with 13k miles (where has it been!!!?). You plan to drive it 5k miles a year. If all goes well, in 17 years you'll still be under 100k miles. All will probably not go well, alas. At that point the car would be 37 years old. There is a substantial risk that sometime before then some no-longer-made part will break. IMHE, that risk is much larger than the risk of internal engine wear - crankshaft bearings, rings, etc - sidelining the car before 100k miles.

From a coldly rational economic point of view, I'd use whatever oil is cheap.

That's not to say I might not use synthetic. I tend to treat machinery like a pet, where you feel guilty buying cheap pet food. But if I was a fleet manager wearing my green eyeshade, cheap oil it would be.

(as an aside, I'd keep a very close eye on rubber parts, e.g. belts and cooling hoses. If they are original I'd change them when reasonably practible; it sux to get stranded by a failed belt or hose).

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Re: Synthetic oil or not for very low mileage auto?

Post by flyingaway » Fri May 17, 2019 10:24 am

EdNorton wrote:
Fri May 17, 2019 9:04 am
I have a 1999 Miata and doing first oil change since purchase. It now has 13,000 miles, never had synthetic oil. I'll probably drive it less than 5k miles/year. Just purchased last July.
I use synthetic oil once a year, you have to change regular oil every 3 months.

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Re: Synthetic oil or not for very low mileage auto?

Post by Teague » Fri May 17, 2019 10:52 am

flyingaway wrote:
Fri May 17, 2019 10:24 am
EdNorton wrote:
Fri May 17, 2019 9:04 am
I have a 1999 Miata and doing first oil change since purchase. It now has 13,000 miles, never had synthetic oil. I'll probably drive it less than 5k miles/year. Just purchased last July.
I use synthetic oil once a year, you have to change regular oil every 3 months.
That 3 month change notion comes from the oil change shops in order to drum up business. I have a hard time envisioning a situation where it would actually be appropriate.
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Re: Synthetic oil or not for very low mileage auto?

Post by flyphotoguy » Fri May 17, 2019 11:24 am

I used to use synthetic when I was younger (Mobile 1). Now we just use normal oil and have it changed during the recommended mileage/time and never had any issues. Both our cars are high mileage now too ( >150K miles) but what's getting replaced are the normal wear and tear items such as brake pads, light bulbs, tires, etc. Synthetic is the better quality oil so use it if you prefer. I'm not sure if newer cars require it or what but we're buying a newer car soon and if it requires, or it's last oil change is using synthetic we will use that too going forward.

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Re: Synthetic oil or not for very low mileage auto?

Post by researcher » Fri May 17, 2019 1:48 pm

EdNorton wrote:
Fri May 17, 2019 9:04 am
I have a 1999 Miata and doing first oil change since purchase. It now has 13,000 miles, never had synthetic oil. I'll probably drive it less than 5k miles/year. Just purchased last July.
What do you mean by "it now has 13,000" miles?
- Is that the total number of miles on the odometer? If so, this is likely the lowest mileage vintage Miata in existence!
- Or is that the number of miles since the last oil change? If so, you drove WAY more miles than you should have between oil changes.

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Summit111
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Re: Synthetic oil or not for very low mileage auto?

Post by Summit111 » Fri May 17, 2019 2:26 pm

Synthetic Mobile 1 in my Tacoma with 300,500 miles, and my 4 Runner with 145,000 miles.

Summit

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Re: Synthetic oil or not for very low mileage auto?

Post by WhiteMaxima » Fri May 17, 2019 3:02 pm

if you have a turbo DI engine, stay with synthetic with low NOACK (some kind of hi temp ash rate). Penzoil (shell) 0W30 european true synthetic.

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Re: Synthetic oil or not for very low mileage auto?

Post by mmmodem » Fri May 17, 2019 3:06 pm

I used to be a courier so I've done more oil changes than a non-mechanic person would. My 2002 and 2006 Honda Civic owners manual recommended conventional oil on what usually turned out to be 10k miles or one year oil change intervals. So that's what I did and both vehicles ran perfectly. Therefore, I have no issues using conventional oil over synthetic.

I don't agree that using conventional is being cheap or you're taking a risk to save a few bucks. I liken it to a fast food burger versus a sit-down restaurant burger. One tastes better than the other but both will satisfy your hunger just the same. Using synthetic when it is not required is not cheap insurance. It's spending more money for peace of mind.

Conventional oil and engine design has made incredible strides in performance. The 3000 mile/3 month conventional oil change is no longer relevant but many will still hold onto that.

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Re: Synthetic oil or not for very low mileage auto?

Post by birdog » Fri May 17, 2019 3:14 pm

Super Tech full synthetic oil from Walmart (produced by a major unnamed supplier) costs less than a lot of conventional (non-synthetic) oils and in a blind analysis from an independent lab compared very well to Mobil-1. Mobil-1 is the official oil of NASCAR and they advertise quite a bit. The cost of their oil is higher because of this. We as consumers pay for that. If you don't want the much cheaper Super Tech, Mobil-1 is on sale quite a bit at Costco (6 qts for $27.69 in my area). If you change your oil and filter regularly, it probably doesn't matter much. If you change it at longer intervals, synthetic will hold up much better. Many newer cars require synthetic or the warranty is voided. My 2014 Chevy Tahoe and my wife's 2014 GMC Acadia both must have Dexos certified oil (which means synthetic blend or full synthetic) or else the engine is not covered under factory warranty. I had to sign a document acknowledging that when I bought both vehicles.
Last edited by birdog on Mon May 20, 2019 7:07 am, edited 1 time in total.

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Re: Synthetic oil or not for very low mileage auto?

Post by nisiprius » Fri May 17, 2019 3:19 pm

I follow the owner's manual.

My current car owner's manual specifies synthetic oil, with a specific grade code I don't remember--it's a different system from that used for conventional oils--and 10,000 mile changes, so that's what I do.

My previous car owner's manual specified a conventional oil and 5,000 mile changes, so that's what I did.
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Re: Synthetic oil or not for very low mileage auto?

Post by midareff » Fri May 17, 2019 3:20 pm

Mobil 1 full synthetic..... using the best oil in a car is the cheapest thing you can do in the long run.

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Re: Synthetic oil or not for very low mileage auto?

Post by neilpilot » Fri May 17, 2019 3:34 pm

WhiteMaxima wrote:
Fri May 17, 2019 3:02 pm
if you have a turbo DI engine, stay with synthetic with low NOACK (some kind of hi temp ash rate). Penzoil (shell) 0W30 european true synthetic.
Wow, I had no idea there was anything like a turbo diesel Miata

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Re: Synthetic oil or not for very low mileage auto?

Post by WhiteMaxima » Fri May 17, 2019 3:36 pm

neilpilot wrote:
Fri May 17, 2019 3:34 pm
WhiteMaxima wrote:
Fri May 17, 2019 3:02 pm
if you have a turbo DI engine, stay with synthetic with low NOACK (some kind of hi temp ash rate). Penzoil (shell) 0W30 european true synthetic.
Wow, I had no idea there was anything like a turbo diesel Miata
gas direct inject (GDI). Mazda name it skyactive. Mazda's plug-free homogenous charged gas direct inject engine is under developement (very similar like diesel direct inject). The thermal effeciency is above 50%.

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EdNorton
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Re: Synthetic oil or not for very low mileage auto?

Post by EdNorton » Fri May 17, 2019 3:52 pm

researcher wrote:
Fri May 17, 2019 1:48 pm
EdNorton wrote:
Fri May 17, 2019 9:04 am
I have a 1999 Miata and doing first oil change since purchase. It now has 13,000 miles, never had synthetic oil. I'll probably drive it less than 5k miles/year. Just purchased last July.
What do you mean by "it now has 13,000" miles?
- Is that the total number of miles on the odometer? If so, this is likely the lowest mileage vintage Miata in existence!
- Or is that the number of miles since the last oil change? If so, you drove WAY more miles than you should have between oil changes.
I purchased the car with 10,400 miles, from the original owners widow. Last oil change was 10,250 per window sticker. Replaced the original tires and haven't done anything else. Car runs beautifully. Not the fastest car, but it's more fun to drive a slow car fast, than a fast car slow.
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Re: Synthetic oil or not for very low mileage auto?

Post by WhiteMaxima » Fri May 17, 2019 4:03 pm

1999 Miata? It is a NA engine, probably require only 10W30 dino oil. There are many use high mileage oil because the gasket and valve seal are aging.

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Re: Synthetic oil or not for very low mileage auto?

Post by Teague » Fri May 17, 2019 4:03 pm

WhiteMaxima wrote:
Fri May 17, 2019 3:02 pm
if you have a turbo DI engine, stay with synthetic with low NOACK (some kind of hi temp ash rate). Penzoil (shell) 0W30 european true synthetic.
Agreed, turbo DI engines have some specific oil requirements that should be followed. The NOACK thing is a measure of volatility, and important to prevent "super-detonation" as I understand it. But was it even possible to have that kind of motor in his 1999 MX-5?
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EdNorton
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Re: Synthetic oil or not for very low mileage auto?

Post by EdNorton » Fri May 17, 2019 4:06 pm

WhiteMaxima wrote:
Fri May 17, 2019 4:03 pm
1999 Miata? It is a NA engine, probably require only 10W30 dino oil. There are many use high mileage oil because the gasket and valve seal are aging.
The 1999 has a NB engine, first year for the NB.
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Re: Synthetic oil or not for very low mileage auto?

Post by MichCPA » Fri May 17, 2019 4:14 pm

Teague wrote:
Fri May 17, 2019 10:52 am
flyingaway wrote:
Fri May 17, 2019 10:24 am
EdNorton wrote:
Fri May 17, 2019 9:04 am
I have a 1999 Miata and doing first oil change since purchase. It now has 13,000 miles, never had synthetic oil. I'll probably drive it less than 5k miles/year. Just purchased last July.
I use synthetic oil once a year, you have to change regular oil every 3 months.
That 3 month change notion comes from the oil change shops in order to drum up business. I have a hard time envisioning a situation where it would actually be appropriate.
But if you are going double the recommended time length, it is still 6 months vs 1 year and synthetic would win out. The time requirement on motor oil is totally legit. Even if you are doing 5k miles per year, you really shouldn't go 18 months between changes. Even independent sources wouldn't suggest going over 6 months on conventional.

https://www.consumerreports.org/car-mai ... -your-car/

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Re: Synthetic oil or not for very low mileage auto?

Post by Teague » Fri May 17, 2019 5:28 pm

^Yes, condensation is a reason to change the oil as often as the manufacturer recommends. Usually that's one year or X number of miles, whichever is first, or whenever the electronic oil monitor says so. Condensation promotes the formation of acids, which are not good for metal parts. Motor oil contains buffers to neutralize acids, the activity of which are measured as "TBN' - total base number. This is why I had suggested OP choose an oil that will maintain its TBN well, as the OP is unlikely to hit the mileage limit before the time limit. If Mazda says change the oil at least every 6 months then OP should do that, but I doubt that's what the manual says.

I assign little authority to opinions from Consumer Reports' "chief mechanic" vs. my owner's manual which had significant input from the very engineers who designed the engine.
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Re: Synthetic oil or not for very low mileage auto?

Post by bottlecap » Fri May 17, 2019 7:34 pm

I'll be the voice of dissent. Stick with conventional.

Old seals shrink. I presume this is due to age, not mileage. We're not talking tires here.

In my experience, putting synthetic in old vehicles causes leaks. Not a big deal, if you don't care about your garage floor.

If you do, stick with conventional. Leave the synthetic for your new vehicles.

JT

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Re: Synthetic oil or not for very low mileage auto?

Post by finite_difference » Fri May 17, 2019 8:08 pm

badger42 wrote:
Fri May 17, 2019 10:02 am
Synthetic and chance once a year. It'll give better protection for an infrequently driven car, and the marginal cost is minimal.
+1.
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Re: Synthetic oil or not for very low mileage auto?

Post by sunny_socal » Sat May 18, 2019 6:40 am

bottlecap wrote:
Fri May 17, 2019 7:34 pm
I'll be the voice of dissent. Stick with conventional.

Old seals shrink. I presume this is due to age, not mileage. We're not talking tires here.

In my experience, putting synthetic in old vehicles causes leaks.
Not a big deal, if you don't care about your garage floor.

If you do, stick with conventional. Leave the synthetic for your new vehicles.

JT
That sounds like internet lore. I've been changing my own oil for 30 years and have used regular and synthetic. My cars did not know the difference nor did they leak.

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Re: Synthetic oil or not for very low mileage auto?

Post by strafe » Sat May 18, 2019 6:59 am

Mobil1 full synthetic costs $13 total for a 5 quart jug ($23 at Walmart minus $10 online/mail-in rebate that runs most of the year). Pennzoil Platinum often has similar rebates and pricing.

The added cost of synthetic oil, if any, is minimal compared to conventional oil.

I don't think the decision is worth the time you've put into this.

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Re: Synthetic oil or not for very low mileage auto?

Post by jabberwockOG » Sat May 18, 2019 7:12 am

strafe wrote:
Sat May 18, 2019 6:59 am
Mobil1 full synthetic costs $13 total for a 5 quart jug ($23 at Walmart minus $10 online/mail-in rebate that runs most of the year). Pennzoil Platinum often has similar rebates and pricing.

The added cost of synthetic oil, if any, is minimal compared to conventional oil.

I don't think the decision is worth the time you've put into this.
This 100%. Absolutely no reason to run dino oil if you shop smart.

Buy engine oil twice a year when it is on sale and there is a rebate in effect. We have two cars don't drive much in our small town so at this point I do once a year oil changes. Recently Amazon had Penzoil Platinum 5w-30 High Mileage 5 quart jug for $22.68 delivered, and there is a $10 rebate (limit 2 rebates so I bought 2). Cost after rebate was $25.36 for 10 quarts delivered for high quality full synthetic oil.

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Re: Synthetic oil or not for very low mileage auto?

Post by GMCZ71 » Sat May 18, 2019 9:30 am

As long as the engine has quality clean oil and a new filter at required intervals it will out last other parts on the car.
John

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Re: Synthetic oil or not for very low mileage auto?

Post by TBillT » Sat May 18, 2019 9:55 am

Synthetic is not really synthetic anymore.
Years ago Mobil lost a court case where the lawyers in their wisdom decided Castrol had the right to call "synthetic" certain higher quality refined oils. So you have to try really hard to buy special stuff like maybe Royal Purple to get what we used to call "true" synthetic...my understanding anyways.

In any case, the guidance would be to follow the directions on the oil bottle and website (such as Mobil-1 has much guidance online). If the oil says not applicable for refills on your older car, by all means follow the directions. But I think they probably say it is OK.

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Re: Synthetic oil or not for very low mileage auto?

Post by WestUniversity » Sat May 18, 2019 11:36 am

Another vote for synthetic...

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Re: Synthetic oil or not for very low mileage auto?

Post by RootSki » Sun May 19, 2019 10:00 am

What oil type is specified in the vehicle’s service/owners manual?

That’s what I would use.

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Re: Synthetic oil or not for very low mileage auto?

Post by KoolAid » Sun May 19, 2019 12:19 pm

jabberwockOG wrote:
Sat May 18, 2019 7:12 am

This 100%. Absolutely no reason to run dino oil if you shop smart.

Buy engine oil twice a year when it is on sale and there is a rebate in effect.
[ quote fixed by admin LadyGeek]

You know, you just saved me $24. I searched for Mobil1 rebates and there is a current rebate in effect. I bought it a month ago, but this brings the price of one 5qt Full syn bottle down to about $10 from walmart... How can you beat that?!

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Re: Synthetic oil or not for very low mileage auto?

Post by JPH » Sun May 19, 2019 1:18 pm

What’s the best oil to use?
Ah, the million dollar question. We are an independent lab, so we don’t make recommendations. It has been our experience that oil is oil, and either petroleum or synthetic-based oil will work well for just about any engine.

Come on, you’re holding out on me. I should use synthetic, right?
Buddy, you should use whatever you want. Synthetic oil won’t guarantee a longer engine life any more than my eating organic food will guarantee I’ll live until I’m 90. We here at Blackstone generally use regular petroleum-based oil because honestly, it works just as well for us.
This copied from the FAQ page at Blackstone Laboratories
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Re: Synthetic oil or not for very low mileage auto?

Post by whodidntante » Sun May 19, 2019 1:32 pm

Like Nisi said, if the car manufacturer recommends synthetic, use it. They probably have a reason. I would also change it according to the recommendations in the manual. A lot of arguments over oil could be solved by reading the brief and easy to understand pertinent pages in the owner's manual. That gives a well informed lower bound for what you should be doing. You're free to change it every day with the most expensive oil you can find if you like burning money.

Synthetic oil degrades slower than conventional oil and has much better low-temperature flow near the end of the drain interval. Since I live in a horrible northern state where it gets water freezes before it can hit the ground cold, I use synthetic these days. But the truth is that the last engine I owned that significantly degraded due to engine wear was a 1977 F-100 that had rolled the odometer three times on conventional oil, and my Lincoln Town Car with conventional oil was still just fine at 230,000 miles. So I probably waste money by buying synthetic oil.

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Re: Synthetic oil or not for very low mileage auto?

Post by Teague » Sun May 19, 2019 1:36 pm

JPH wrote:
Sun May 19, 2019 1:18 pm
What’s the best oil to use?
Ah, the million dollar question. We are an independent lab, so we don’t make recommendations. It has been our experience that oil is oil, and either petroleum or synthetic-based oil will work well for just about any engine.

Come on, you’re holding out on me. I should use synthetic, right?
Buddy, you should use whatever you want. Synthetic oil won’t guarantee a longer engine life any more than my eating organic food will guarantee I’ll live until I’m 90. We here at Blackstone generally use regular petroleum-based oil because honestly, it works just as well for us.
This copied from the FAQ page at Blackstone Laboratories
https://www.blackstone-labs.com/?sessio ... y%29%29%2F
All well and good, but this is the Internet, and expert opinion carries no special weight in these parts. Besides, a miniature NASCAR driver on TV and my trusted labradoodle both recommend synthetic. :D
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Re: Synthetic oil or not for very low mileage auto?

Post by inbox788 » Sun May 19, 2019 5:25 pm

whodidntante wrote:
Sun May 19, 2019 1:32 pm
Like Nisi said, if the car manufacturer recommends synthetic, use it. They probably have a reason. I would also change it according to the recommendations in the manual. A lot of arguments over oil could be solved by reading the brief and easy to understand pertinent pages in the owner's manual. That gives a well informed lower bound for what you should be doing. You're free to change it every day with the most expensive oil you can find if you like burning money.

Synthetic oil degrades slower than conventional oil and has much better low-temperature flow near the end of the drain interval. Since I live in a horrible northern state where it gets water freezes before it can hit the ground cold, I use synthetic these days. But the truth is that the last engine I owned that significantly degraded due to engine wear was a 1977 F-100 that had rolled the odometer three times on conventional oil, and my Lincoln Town Car with conventional oil was still just fine at 230,000 miles. So I probably waste money by buying synthetic oil.
These very extreme situations are challenging to deal with. 300k+ and 230k is a lot of miles, though annually over the decades, maybe not so much. So long as the engine was properly lubricated, engine wear shouldn't have been much of an issue.

I generally go by the manual, but we're dealing with extremely LOW mileage here, on the order of 500 miles/years!?! OP is driving 5-10X as much as the original owner, and is still low annual mileage.

I do believe that synthetic oil degrades less and performs better aged, but have little actual real life data and evidence for that. And I live in a climate where low temperature isn't an issue. Still, if a car manufacturer recommends 1 year/5k miles as lower bound, and I'm only driving 500 miles, I don't worry about 18 or 24 months and driving it 1000 miles using any kind of motor oil. And using synthetic in this situation makes me worry even less. If OP is putting 3-5k/year, annual oil changes with synthetic would be more than enough from a lubrication standpoint IMO. If synthetic oil happens to be associated with oil leaks, going with a high mileage or thicker oil or back to conventional oil often seems to seal things up again.

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Re: Synthetic oil or not for very low mileage auto?

Post by whodidntante » Sun May 19, 2019 7:17 pm

inbox788 wrote:
Sun May 19, 2019 5:25 pm
whodidntante wrote:
Sun May 19, 2019 1:32 pm
Like Nisi said, if the car manufacturer recommends synthetic, use it. They probably have a reason. I would also change it according to the recommendations in the manual. A lot of arguments over oil could be solved by reading the brief and easy to understand pertinent pages in the owner's manual. That gives a well informed lower bound for what you should be doing. You're free to change it every day with the most expensive oil you can find if you like burning money.

Synthetic oil degrades slower than conventional oil and has much better low-temperature flow near the end of the drain interval. Since I live in a horrible northern state where it gets water freezes before it can hit the ground cold, I use synthetic these days. But the truth is that the last engine I owned that significantly degraded due to engine wear was a 1977 F-100 that had rolled the odometer three times on conventional oil, and my Lincoln Town Car with conventional oil was still just fine at 230,000 miles. So I probably waste money by buying synthetic oil.
These very extreme situations are challenging to deal with. 300k+ and 230k is a lot of miles, though annually over the decades, maybe not so much. So long as the engine was properly lubricated, engine wear shouldn't have been much of an issue.

I generally go by the manual, but we're dealing with extremely LOW mileage here, on the order of 500 miles/years!?! OP is driving 5-10X as much as the original owner, and is still low annual mileage.

I do believe that synthetic oil degrades less and performs better aged, but have little actual real life data and evidence for that. And I live in a climate where low temperature isn't an issue. Still, if a car manufacturer recommends 1 year/5k miles as lower bound, and I'm only driving 500 miles, I don't worry about 18 or 24 months and driving it 1000 miles using any kind of motor oil. And using synthetic in this situation makes me worry even less. If OP is putting 3-5k/year, annual oil changes with synthetic would be more than enough from a lubrication standpoint IMO. If synthetic oil happens to be associated with oil leaks, going with a high mileage or thicker oil or back to conventional oil often seems to seal things up again.
There are a few videos on youtube where people test synthetic and conventional oil cold flow after a drain, or after heating the oil in a controlled way. Here's one.

https://m.youtube.com/watch?v=a9DWGtXpYUc

researcher
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Re: Synthetic oil or not for very low mileage auto?

Post by researcher » Sun May 19, 2019 7:27 pm

jabberwockOG wrote:
Sat May 18, 2019 7:12 am
Recently Amazon had Penzoil Platinum 5w-30 High Mileage 5 quart jug for $22.68 delivered, and there is a $10 rebate (limit 2 rebates so I bought 2). Cost after rebate was $25.36 for 10 quarts delivered for high quality full synthetic oil.
Thanks for the tip.

I just ordered two 5-qt jugs from Walmart.com for $22.58 each.
As an added bonus, they come with 2 free rolls of Scott shop towels!

I'll submit my $20 rebate on Tuesday when the oil arrives.

https://www.walmart.com/nco/Pennzoil-0W ... e/47217500

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Re: Synthetic oil or not for very low mileage auto?

Post by Wakefield1 » Sun May 19, 2019 7:57 pm

sunny_socal wrote:
Sat May 18, 2019 6:40 am
bottlecap wrote:
Fri May 17, 2019 7:34 pm
I'll be the voice of dissent. Stick with conventional.

Old seals shrink. I presume this is due to age, not mileage. We're not talking tires here.

In my experience, putting synthetic in old vehicles causes leaks.
Not a big deal, if you don't care about your garage floor.

If you do, stick with conventional. Leave the synthetic for your new vehicles.

JT
That sounds like internet lore. I've been changing my own oil for 30 years and have used regular and synthetic. My cars did not know the difference nor did they leak.
Very early synthetic oils were said to cause leaks,perhaps because of different seal swell characteristics than old style oil. But supposedly that has been worked out.
There is a Valvoline oil line,comes in both non synthetic and synthetic,that is supposed to have increased seal swell ingredient to reduce the tendency to leak. I think is branded "MaxLife High Mileage" .

Wakefield1
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Re: Synthetic oil or not for very low mileage auto?

Post by Wakefield1 » Sun May 19, 2019 8:06 pm

Synthetic oil (or higher quality conventional oil labeled as synthetic) is said to offer more protection from deposits of varnish like matter on interior engine surfaces,which could be a plus for engines with extremely small passages for metering oil pressure to hydraulic limited angle motors used to advance and retard cam timing on complex variable valve timed engines such as Fords with "phasers" on the camshafts (limited angle motor rotates cam a few degrees either way from its driven end)

inbox788
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Re: Synthetic oil or not for very low mileage auto?

Post by inbox788 » Sun May 19, 2019 9:19 pm

whodidntante wrote:
Sun May 19, 2019 7:17 pm
There are a few videos on youtube where people test synthetic and conventional oil cold flow after a drain, or after heating the oil in a controlled way. Here's one.

https://m.youtube.com/watch?v=a9DWGtXpYUc
Yes, I've seen those comparisons, and the comparisons are impressive, but I'm not sure how that translates to an engine that's going getting driven a few thousand or less miles a year. Or what that means to extending your oil change interval if you're driving a lot. The only conclusion I make is that you're doing less damage with the better oil, but is it a significant difference in an actual engine? It could mean the difference between 500k vs 1M miles, but not practically speaking for regular drivers and less so for very low mileage drivers.

I've toyed with the idea of oil analysis, but even if 2 year old oil check out, would I feel confident letting it go another year or 2, and then what, do another analysis? I wouldn't be surprised if a hardly driven car had oil analysis come back after 4 years showing the oil was still like new, and if that were the data, would you leave it in for another 2 years? Because the cost of the analysis is nearly the same as an oil change, it's simpler to just change the oil and not worry about it.

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whodidntante
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Re: Synthetic oil or not for very low mileage auto?

Post by whodidntante » Sun May 19, 2019 9:33 pm

inbox788 wrote:
Sun May 19, 2019 9:19 pm

Yes, I've seen those comparisons, and the comparisons are impressive, but I'm not sure how that translates to an engine that's going getting driven a few thousand or less miles a year. Or what that means to extending your oil change interval if you're driving a lot. The only conclusion I make is that you're doing less damage with the better oil, but is it a significant difference in an actual engine? It could mean the difference between 500k vs 1M miles, but not practically speaking for regular drivers and less so for very low mileage drivers.
I think it's clear that synthetic does better flow better than conventional oil at the end of a reasonable oil drain interval, with actual driving. But I agree that the improved flow may not matter much in real engines.

For an engine that is seldom driven, I would take a wild guess that water accumulation is an issue in the engine and in the oil, that some surfaces could go dry and be more likely to corrode as all the oil drains away. The engine could suffer internal corrosion that eventually would put an end to it. Using the engine more often and keep fresh oil in the engine would go a long way towards keeping the engine viable (again just guessing). But I don't think synthetic oil would help at all.

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