is fully synthetic really worth the extra?

[CliveM]

is fully synthetic really worth the extra? or if the oil reaches the min standard, is there no benefit of a higher grade?

Do the sythns give better MPG or any other benefit?

 

[jaques2k]

Higher viscosity, or SAE range (ex. 5W-50 is better than 10W-40) gives better lubrication when the weather is colder or when running the engine at high rpm:s for a long time (heat resistance). Therefore, a oil that reaches the min. requirements or standard lubricates mostly well, but a full syntethic is thinner at lower temps (just after you´ve started the engine when cold weather - or when running at higher temps) and therefore may give somewhat better protection to the engine parts. If you want your engine to last a very long time without major reparations you´ll better drive with a good oil quality. If you don´t think your car will stay alive for more than 15-20 years, then you can without problem drive with a oil that meets the minimum requirements (assuming you aren´t participating in any highway races or driving in -20 degrees celsius).

The fuel consumption may be a bit better if you often have cold weather (-15 to -20 degrees celsius or less) and not using a pre-heater, because the full syntehetic oil is thinner in lower temps and causes the engine to run more easily until it warms up.
Well, now I have written my opinion about this... =)

 

[ant500sl]

With newer vehicles and extended oil change intervals of 9 or more thousand miles a synthetic oil is necessary as mineral oils will break down over these long periods of use. However with older cars on 3 or 6 thousand mile oil changes a good mineral or semi synthetic oil will be fine.

Remember that Mercedes reputation for long lasting engines is based on vehicles that were designed when Mobil 1 was unheard of and regular changes of oils that we would now describe as rubbish was the norm.

Just my humble opinion on a very complex subject.

 

[AlanWT]

I was recently sent on a health & safety course ('COSHH' - ugh!), which was also attended by a scientist from Shell research laboratories. His opinion on this was that, for normal day to day use, the difference in performance between normal and fully synthetic oil is minimal provided that the oil is changed regularly. He said that the performance of non-synthetics deteriorates much more rapidly than that of fully-synthetics once the recommended period of use has been reached.

Hope this helps

Alan