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Re: OILS and ADDITIVES Posted by Ari [Email]  (#2847) [Profile/Gallery]
(more from Ari) on Mon, 13 Jan 2003 08:54:30
In Reply to: OILS and ADDITIVES, Paddy, Sun, 12 Jan 2003 22:22:16 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Synthetic oil is much better at maintaining its viscosity over temperature, so it lubricates better when cold, and resists breakdown when hot. It will be a little easier for the engine to turn over with synthetic - I really doubt you'd see a big change in cranking speed, but anything is possible. I have to believe the ability to pull away without stalling is a coincidence. I also have to say that you should ALWAYS let the engine idle for a little when cold ( 10-20 seconds at least) before driving off - even synthetic oil needs time to circulate.
Your mechanic's comments about synthetic oil being thicker is, to be kind, entirely wrong. You buy oil based on it's vicosity - incorrectly called weight, but the name has stuck. 10W-30 oil is the same thickness, 'normal' or synthentic. In fact, when cold, synthetic oil is actually a little thinner than 'normal' oil, so it flows better.
Now, if you use 50W synthetic, it will be thicker than 20W 'normal'. But I assume that you are using the oil weight as specified in the manual (usually 10-30 or 10-40). So your mechanic is speaking crap. Ooops, I should be nicer.
As to additives - Good quality oils contain the additves they need. Castrol GTX is just fine, as would be most brand-name synthetics. I would NOT put in any additives for many reasons. First, there are many oil additives that are nothing but snake oil - promising better mileage, no oil leaks, 10 extra HP, and a better sex life. Pure crap. (There I go again, sorry). If there were any such additives, don't you think Castrol, Penzoil, or the rest would use them?
Second, engine oil already has many 'additives' - these control viscosity, buffer acids, remove varnish, and the like. Oil is a very complex chemical soup. When you add additives, you're adding more chemicals to the soup. You can't assume that they will all play together nicely. The goop you add may very well neutralize itself and something useful in the oil, or worse, combine to form something nobody intended.
So save your money on additives - use a good oil, synthetic or 'normal', and change it and the filter regularly.
posted by 192.249....
, Mon, 13 Jan 2003 08:54:30 <-- Viewing This Message
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