synthetic vs. dino... again

MrPants · 10-03-2003, 12:03 AM

is there any reason aside from cost NOT to use synthetic? ive heard its 'thinner' than dino oil but cant that problem be solved by using a higher weight oil?
anyone had first hand negative experience with either?

rammstein · 10-03-2003, 05:04 AM

If you are currently using Dino and have leaks, synthetic will REALLY leak.

pearldrum · 10-03-2003, 05:09 AM

I switched to synthetic and had an oil leak before with dino. It didn't seem to get much worse if it did, maybe it will soon...

CJFusco · CJFusco's Garage

a quote from my mechanic: "Synthetic is great, but it always seems to figure out a way to leak."

Sneaky synthetic oil.

BlueQuestTSi · 10-03-2003, 08:17 AM

Quote:

Originally posted by CJFusco
a quote from my mechanic: "Synthetic is great, but it always seems to figure out a way to leak."

Sneaky synthetic oil.

Synthetic usually has better cleaning agents, and doesn't gum up like dyno oil does. Dyno oil may gum up seals, thus preventing leaks. So, if you have a small oil leak with dyno oil, the oil itself could be coking up the leak somewhat and prevent it from being a massive leak. Throw in Synthetic, and it starts to clean out the gummed up dyno oil, and will eventually cause a drip to become a gusher(so-to-speak).

I don't recommend changing a high mileage car to synthetic due to leaking capabilities. Always switch to synthetics on a low mileage engine, it's best to make the switch just after a new engine break in.

scheistermeiste · 10-03-2003, 09:01 AM

would one have a problem switching from synthetic to dino?

Mark_944S2 · 10-03-2003, 09:43 AM

If its the same grade I can't see it leaking more. Search out Mobil 1 15/50, the heaviest grade they make - I put it in a 115K mile S2 with no problems.

Synthetic is a much, much better oil than Dino and will make your engine last longer - bottom line.

Advantages include :

No or reduced use of viscosity modifiers which are what break down quickest in dino oil and make it go out of grade

Better viscosity behaviour over wide temp / pressure ranges : ie its thinner when cold, stays thicker / stands up to higher pressures when hot.

Both these things make it a better oil for any engine, old or new.

Obviously if you put Mobil 1 0/30 in an old leaky engine it'll leak like a sieve - 15/50 should be fine.

Mark

ds475 · 10-04-2003, 01:53 AM

Mobil1 is recommended?...

CJFusco · CJFusco's Garage

Mobil 1 is the oil recommended by Porsche

Manute · 10-04-2003, 07:39 AM

But would it be disadvantages switching from synth to dino?
At the factory they told me to change to reduce oil consumption....there is no problem? what grade?

I use BP 5W40 synth,also recommended to Porsche....Now they recommend Mobil 1...do you know what this cost at the factory? About $120 6 liters when changing it...

The porsche recommended oil is the one that can pay it´s commercial rights,as always.

Britwrench · 10-04-2003, 08:40 AM

How many posters have actually seen, or know of, oil related engine failures in any car? I don't mean abuse, running low of oil, lack of realistic oil change intervals, but real, the engine broke because the oil failed, problems. I'm thinking hard here and there isn't one I can remember. Change the oil reasonably regularly, don't drive hard until the engine has warmed up properly and it will last as long as you own the car. Obviously, other things might/will break, YMMV.

Mark_944S2 · 10-04-2003, 11:15 AM

Numerous. I've had 2 cars where the engine was just plain worn out - ie low on compression, noisy cams etc. Also some 944s have this tendancy to spin main bearings which quality oil can certainly help to avoid.

When you consider the improved fuel consumption, the need to change the oil less often, and the improved engine life synthetic doesn't cost any more.

Economics :

Lets say on Dyno oil your engine lasts 180K miles.

At 5K oil changes and $15 per change (oil and filter) thats 180/5 x 15 = $540

Synthetic @10K changes and $35 per change (oil and filter) = $630

Over 180K miles you'll spend $16000 on fuel. Save only 1% (and I think it'll be more like 5%) with synthetic and thats $160.

Synthetic is cheaper even if your engine life is the same. Then consider half the pollution from used engine oil (it has to be recycled, it doesnt just disappear you know.)

A full rebuild on an S2 engine is something like 8K. If you spin a main bearing it's expensive too.

I don't know many people who've had their house burn down but I still take out insurance.

Mark

Britwrench · 10-04-2003, 11:58 AM

Yes, agree with some of that. However, engines wear out anyway, depending on the make and how they are used. The 944 bearing problem seems to be mainly apparent on track use cars. My point is that actual oil-related failures are rare, whether synthetic or dino oil.
Of course, as I have to work in a shop during the day, my idea of maintaining my own cars and yours is way different!!

Manute · 10-05-2003, 10:40 PM

But...is there really changes in fuel consumption with different types of oil??

I don´t know why if i use dyno,my fuel consumption should be higher...fuel and oil are separate things (suposely),if you can illustrate me....

And if switching to dyno makes me to reduce at least a 10% oil consumption,no matter if i have to change oil more often,but it will be cheaper.
If in the factory told me to use dyno because of the leaks and the oil consumption,they would know what are saying...and dont forget we are using engines designed about 20 years ago,when synthetic is not so usual.