Can you actually go that may mailes before an oil change with synthetics?
What about the stuff that's suspended in the oil being in the engine that
long?
If this is true, then it seems the higher cost of these oils and the Mobil
1 filter would be worthwhile.
Gerard
At 10:31 AM +1000 10/26/99, Mike Gigante wrote:
>I use Mobil 1!!!!
>
>Back in March, I spoke to a scientist for a major oil company.
>
>She tells me that mineral oils *start* to break down at 88C (190F)
>whereas synthetic oils *begin* to breakdown at 200C (392F).
>
>Note these are the temperature at which the first traces of breakdown
>happens. The rate would be very low at those temps, but at the hotter
>parts of your engine (e.g. rings), the rate of breakdown would be
>considerably higher because the local temperature is much higher.
>
>Byproducts of mineral oil breakdown include acids and carbon soot.
>The carbon soot tends to fall out of suspension causing deposits
>throughout the engine. Byproducts of breakdown in synthetics remain
>in solution (hence no deposits)This is why 5000 mile oil changes were/are
>recommended on conventional oils - the oil has been slowly breaking
>down since the engine was first turned over. This is also why 25,000 mile
>oil changes were recommended for synthetics - they didn't have the quantity
>of breakdown by-products and any by-products just remained in solution
>anyhow.
>
>So, personally, I think this clearly sends two messages
>
>a) if you use mineral oils, an oil cooler is a pretty damn good idea.
>
>b) you should seriously think about using synthetics! I have been doing
>so for the past 6 years in my race and rally cars and I have no complaints!
>
>I should say that I do use penrite HPR30 in my road 1100 (was a daily
>driver)
>and in my tow cars. Why, well it still is a very good oil and these engines
>all have
>lots of miles on them since the last rebuild. I did not want to swap over to
>Mobil 1
>on high mileage motors since lots of crud can get picked up and pumped
>through the engine, causing more damage than benefits.
>
>Mike
>
>
>Conventional oils *start* to breakdown at 190F. Sure the rate of breakdown
>is low
>but this means
>----- Original Message -----
>From: <Daniel1312@aol.com>
>To: <mikeg@vicnet.net.au>; <spridgets@autox.team.net>
>Sent: Tuesday, 26 October 1999 5:16
>Subject: Re: STP & engine temperatures
>
>
>> Sounds reasonable so why do some people use Penrite?
>>
>> Daniel1312 - Mobil 1 user
>>
>> In a message dated 25/10/99 11:57:30 GMT Daylight Time,
>mikeg@vicnet.net.au
>> writes:
>>
>> << Since synthetic oil doesn't start to breakdown until a much higher
>> tempertaure than conventional oils, they will not see the buildup of
>> failure by-products around the rings. >>
>>
If you can stay calm, while all around you is chaos... then you
probably haven't completely understood the seriousness of the situation.
G G Gerard Chateauvieux
E A
R R pixelsmith@gerardsgarage.com
A A
R G Pixelsmith on Duty
D E
S http://www.gerardsgarage.com
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