Better oil service for the same money, 1 change of Synth or 2 of SM Conventional?

[Auto-Union]

I know it's a beaten topic, but I'd like to revisit it.
A few items are now to be considered and a few are not to be taken into account. I think we should consider that we really don't know what we are getting with synth as far as service life, that is API specs are the same for conventional and synth. There are GM and ACEA and mfg specs that sorta require synth to meet, but they don't compare DIRECTLY to conventional, that is to say Spec 1X, 2X, 3x does not mean oil lasts 2 times, 3 times longer, etc.

Let's assume that synth price is exactly 2x the conventional price. A jug of Havoline is $9, GTX and others $10. Synths come in about $20 or more.
Lets also assume we have no filter change if we do 2 conventional changes over the interval, as we would just use one filter with the synthetic.
Can we say too that cold climate is not an issue, as well as hot-running turbos that cook oil. Just plain engines and plain oil in plain climates.
Finally, assume no labour costs as no one here really minds draining (and recycling) a fill of oil. It can be done in 2-5 minutes if rushed.

So, the final form of the question is:

What is a better oil service, 2 changes of SM conventional for the same $20 as one change of synth. Let's say 5000-6000 miles verses 10,000, 12,000 for synth, depending on driving cycles.

I pretty much have formed an opinion, but will not interject it, yet.

 

[DJStillman]

I did not realize people were going 10-12000 miles without a filter change. I could've sworn that they changed it at 5-6000 miles...

I know I would not go that long on a plain spin on filter...

Maybe a bypass setup...?

 

[AstroVic]

It's probably six in one hand and half a dozen in the other.

I'd lean more toward 4,000 to 5,000 mile OCIs on the dino juice, and 8,000 to 10,000 OCIs on the synthetic stuff for a more realistic comparison.

I think it's safe to say that it really comes down to how often you want to be changing your oil and filter, as well as your specific budget-consciousness for that particular car.

All three of my cars have high mileage and so it's hard for me to justify the cost of synthetic, especially since any one of them could be lost at any given moment in a wreck, a major (expensive) repair, etc. I guess I kind of consider them throw-away cars, although I don't necessarily treat them as such. Also, I don't mind changing the oil/filter on them in the convenience of my garage, and it gives me a chance to take a look at the other maintenance items while I'm at it.

If I had a newer (more expensive) car, I'd probably use synthetic oil and change it every 5,000 to 7,500 miles - depending on the driving conditions.

 

[BlueWorld]

Not to throw off things with another option, but with a self served GC OCI costing half of what a tank of gas is costing, I see no reason not to change GC every 5K.

 

[toocrazy2yoo]

I do..

Can't GET THE STUFF!!!

 

[oilboy123]

I lean to the synthetic side. I run Amsoil and the last change was 10 months and about 5000 miles.

I will probably run in the one year range now, as long as I don't run past about 14-15000 miles. In the past I have changed out at 9000 miles 6mth time frame.

My dads vehicles will get 1 yr changes.

Another factor is less trips to recycle or less recycled oil and filts to have laying around to deal with. I don't mind changing oil, but don't like to bring the stuff in to the recycle.

Twice the labor for the same amount of miles! I don't think so..........to each their own...

 

[Auto-Union]

Ugh. I'm getting answers to the questions I excluded. No labour assumed. No price correlation, except that Synth is twice as much money and you run it twice as far. Guys who run 12k-15k on AMSoil or M1 EP can be countered by running conventional oil 6000-7500 miles and beyond. The question is not how far to run or how long to do a a filter change, but which is better, synth at 2x the cost and 2x the interval or conventional at one-half the price and interval on a single filter, no labour. FTR Honda filters go 20k and are the size of a lemon.

btw- I drive 30k a year now and service quite a few family and friend's cars, saving money on OC is signifigant and I don't mind doing the work. (I own an extractor if I get lazy)

 

[Auto-Union]

Not to break my own rule of answering the question directly, but rather to suggest a way of looking at it. I ask what would be better for the engine, cleanliness and wear, if that can really be measured. Now, I suggest that looking at the service MILES that can be achieved with 2 changes of good "conventional"...like Motorcraft 5w-20, Havoline 5w-30, GTX...whatever, at $2 a pop ($10/5q jug) or Synth that is sold by the jug, like $20 which includes PP, M1, Syntec, et al.

I say 10k is a breeze on SM conventional, so compare synth at 20k miles???? See where I'm getting? Conventional is a far better option at whatever interval you choose as long as you compare it to Synth at 2x the cost and 2x the interval.

 

[HTSS_TR]

No filter change between 2 conventional oil changes over the same interval may leave about 1/2 quart of old oil in the old filter. Because of this, I would go with synthetic oil for 12k miles or 1 year whichever is first, that is what I am doing for my '00 E430 and '94 LS400.

 

[Clyde65]

I would rather do two changes with a blend as opposed to one change with full synthetic at twice the interval. Maxlife 3 times a year with AC Delco PF47's.

 

[The Critic]

I'd choose conventional oil with more frequent changes. This way, contaminants are removed on a more frequent basis.

 

[AstroVic]

quote:

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Originally posted by The Critic:
I'd choose conventional oil with more frequent changes. This way, contaminants are removed on a more frequent basis.

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I'd agree with that, too.

 

[jorton]

I, three.

If I could afford it I would change with synthetic 3 times a year.

Another thing to calculate in the original question is UOA. BIOG used to recommend UOA for extended drains, so that brings the cost to more than double for synthetic.

 

[TooSlick]

I'd say it depends on the quality of the synthetic you're using, which varies widely....

TS

 

[Pablo]

quote:

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I'd choose conventional oil with more frequent changes. This way, contaminants are removed on a more frequent basis.

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Can we have backing evidence please? Statistical data that say 10K or 12K on a good synthetic will allow some deleterious build up of contaminants?

I thought this myth died several years ago.

I will contend that UOA's prove this contaminant idea a blind alley of oil evolution.

 

[fred0803]

Never surprised with the type of questions asked. You know that asking this question will give a varieties of "opinions" and nothing more.
Do what you want to do. There is not a clear answer to that and you knew it before you asked it.

 

[icruse]

I would say it is a wash. The regular oil will not hold up as long as a quality synthetic and (to each his own) it is kind of frivolous to change synthetic oil too soon.
So whatever suits your own preference (and peace of mind) will work just fine, as long as it is done with a good consistent change interval.
I live in northern Minnesota, but since you said to leave the cold weather out, I won't go there.

Good Day,
Steven

 

[friendly_jacek]

It is not a wash if one looks at the enviromental impact. People in US may not care but Europe went the synthetic/12 months/10,000 miles (or more) route for the enviromental reasons. Used oil is considered waste and has to recycled. Not 100% can be recycled though as some oil is pitched inside filters, spilled, etc.

 

[JAG]

I think there could be less wear over twice the interval with synthetic than over the two intervals (same total mileage) with dino IF the synthetic is a good one. There certainly would be less crankcase oil evaporation with the synthetic which ends up in the PCV system and back into the cylinders to be burned. The rings should stay cleaner with the synthetic because of less cylinder wall burnoff as well. The synthetic should run slightly cooler due to higher thermal conductivity and give a little more power. The only advantage I see with dino and changing it twice as often is having an average of half the amount of dirt in the oil with dino vs synthetic, but I think this advantage is outweighed by the other factors.

This all hinges on picking the right synthetic and they aren't all equal.

 

[Triple_Se7en]

quote:

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Originally posted by Auto-Union:
I know it's a beaten topic, but I'd like to revisit it.
A few items are now to be considered and a few are not to be taken into account. I think we should consider that we really don't know what we are getting with synth as far as service life, that is API specs are the same for conventional and synth.

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Dino specs are not the same with many syn-oils.

You "should know" how synthetics increase service life. They also keep your engine cleaner & overall better temp protection in extreme weather.

Synthetics should be a no-brainer for anyone with a newer vehicle that doesn't lease. You pay 25K for the vehicle ($450 month hypothetical)... so why not $2-$4 more per month to better-maintain it?

That is... unless you enjoy crawling under the vehicle & getting dirty more often every year. Dinos are fine - synthetics are overall better & a no-brainer for many of us who are first & last owners of our vehicles.

BITOG should require that threads like this include how long you plan on keeping the vehicle & if it's a lease or ownership agreement. It makes all the difference in the world when trying to sort-out the proper answer.

Personally, if I were leasing, I would never buy synthetic oils for the normal, typical passenger vehicle today. I would also go by either the OLM or the maximum OCI allowance in the owners manual.

But being an owner of that vehicle changes everything!!!!!