| Author |
Message |
Hubert Otlik (Hugh)
Member
Username: Hugh
Post Number: 307
Registered: 1-2002
| | Posted on Friday, November 15, 2002 - 3:14 pm: | |
Here is my take :
Synthetic vs. Conventional Oils:
The most striking difference b/w synthetic oils and conventional or so called petroleum based oils is the homogeneity of the carbon molecule(s) or -using the jargon- alkane(s) lengths. Meaning the composition and effectivly the weight of the synthetic oil is an exact defenition of the molecular composition of that oil. So, when you buy 10W-30 oil, its been engineered to have a composition of alkane's that give the oil an exact cold viscocity of 10W oil, and an operating temp viscocity of 30W oil. In contrast to petroleum/conventional or "dino juice" based oil, the alkane lengths are variable and have a compostion more akin to a polydispersed [short chains mixed along w/ medium length chains and long chain alkanes], than the monodispersed synthetic oil.
So, the weight of the conventinal oil is more of an estimate than an exact measurement, this is what makes the conventional oil more succeptible to breakdown. Much akin to knock in a combustion cycle, when and organic molecule under extreme heat and pressure can form a radical [ an atom with one lone electron] species-very reactive and dangerous- this causes a chain reaction w/in the combustion chamber, breaking down the surrounding carbon molecules and propogarting the formation of more and more radicals eventually leading to spontaneous combustion or knock. This spontanous radical formation is also possible w/ engine oil, when exposed to high heat the possibility of radical formation increases, the radical species formed is capable of reacting w/ the metals and material w/in the motor, and the surrounding oil particles-accelarating their degridation and breakdown-leading to a chain reaction that leads to the breakdown of the oil. Which can, at the extreme, cause metal to metal contact, gasket degridation-as we know rubber and plastic harden and become brittle when exposed to high temp/burned then allowed to cool.
Synthetic oil, however, is less likely to succumb to such conditions largly b/c of its greater degree of molecular homogeneity, hence it is able to provide a more consistant barrier b/w the surfaces w/ in the metal against thermal abrasion. And, it itself is more stable hence protecting the internal surfaces-sorry for the redundancy-against radical(s) and the damage therin. One tangential point, synthetic oils b/c of their molecular composition, are somewhat "thinner" than their conventional counterparts, again b/c the alkanes w/ in the oil are engineered to given lengths, unlike the petroleum based oils which are blended together during/after the cracking of the natural stock takes place. That is why some people have complained of leaks when switching to synthtic on a motor w/ high mileage and a lifetime of petroleum based oil use. Rule of thumb, if you've been using petroleum based oil for the majority of the engines life, keep using petroleum based oils, just change the oil more often. Conversly, there should be no ill side effects in going the opposite direction, meaning synthetic to pertroleum based, so go ahead. Keep in mind, however, that going back to synthetic may cause a problem, if you decide to go back.
I used AGIP for a while in my motorcyle, but found that it really wasn't worth it. BTW - Isnt shell reccomended by Ferrari, there's a stamp in the engine bay specifying the weight and type; however, I agree w/ JRV, as far as 'off the shelf oils go- Mobil 1 is the best and considering the cost of it's competitors, is a no brainer.
-Hubert |
JRV (Jrvall)
Junior Member
Username: Jrvall
Post Number: 114
Registered: 11-2002
| | Posted on Friday, November 15, 2002 - 2:20 pm: | |
...another Urban Legend unvieled...AGIP Sint 2000 is a blend...MOBIL 1 is 100% synthetic.
And the best IMO.
Fossil based oils leave a residue and don't have the 'shear strenght' that 'long chain molecule' pure synthetics have.
But AGIP is decent oil, just not the best oil.
But there is a saying...'when you need oil'...any oil is good oil. |
Ben Lobenstein 90 TR (Benjet)
Member
Username: Benjet
Post Number: 883
Registered: 1-2001
| | Posted on Friday, November 15, 2002 - 2:09 pm: | |
IIRC there is only ONE brand of motor oil that is %100 pure synth, most "claimed" synth motor oils (this includes mobile1, redline, AGIP and others) are made from conventional base stocks. This is somehting the mfg reps do not dispute for the most part. Not that there is any harm in this, just something to be aware of. |
TomD (Tifosi)
Intermediate Member
Username: Tifosi
Post Number: 1805
Registered: 9-2001
| | Posted on Friday, November 15, 2002 - 1:43 pm: | |
wow 7 bucks for mix is steep |
Ricky Nardis (Rickyn_f355)
Junior Member
Username: Rickyn_f355
Post Number: 104
Registered: 8-2002
| | Posted on Friday, November 15, 2002 - 1:38 pm: | |
they used the Agip mix....$6.92 a qt....no big deal, I'll have the synthetic put in in April.
thxn guys
|
Adam Goldman '86 TR (Icnsltmfg)
Member
Username: Icnsltmfg
Post Number: 452
Registered: 8-2001
| | Posted on Friday, November 15, 2002 - 11:38 am: | |
I use the AGIP Synt 2000 Synthetic Mix. |
Mark Freeman (Mrpc12)
Junior Member
Username: Mrpc12
Post Number: 99
Registered: 11-2001
| | Posted on Friday, November 15, 2002 - 11:30 am: | |
If you are only going to change the oil once a year and not every 3K miles then I would insist on synthetic. |
TomD (Tifosi)
Intermediate Member
Username: Tifosi
Post Number: 1794
Registered: 9-2001
| | Posted on Friday, November 15, 2002 - 11:09 am: | |
after warranty it prob doesn't matter but they should have told you |
TomD (Tifosi)
Intermediate Member
Username: Tifosi
Post Number: 1793
Registered: 9-2001
| | Posted on Friday, November 15, 2002 - 11:08 am: | |
I think the 355 calls for synth? What did they charge you for it. |
Ricky Nardis (Rickyn_f355)
Junior Member
Username: Rickyn_f355
Post Number: 102
Registered: 8-2002
| | Posted on Friday, November 15, 2002 - 11:03 am: | |
is this what dealers use? Should I be running synthetic? |
|