Synthetic vs Semi Synthetic oils

[rikana]

Hi,
My car is a 98 W140 S320L. I was just at the dealer who has been servicing it and they have service packages where they do lube changes for minor service. When I asked them what lube they use they said either Total quartz 7000 or 9000. The difffrence being one is semi synthetic. I would like my car to be on fully synthetic oil. However, i have heard of people having leak issues when they change. So what is the real diffrence and are there any risks o my using fully synthetic oil??
regards

 

[lupi]

Hi,
My car is a 98 W140 S320L. I was just at the dealer who has been servicing it and they have service packages where they do lube changes for minor service. When I asked them what lube they use they said either Total quartz 7000 or 9000. The difffrence being one is semi synthetic. I would like my car to be on fully synthetic oil. However, i have heard of people having leak issues when they change. So what is the real diffrence and are there any risks o my using fully synthetic oil??
regards

The real difference is in the name itself, semi or fully.
The fully is better, for longer change intervals, i.e. more
miles and not time periods, it is also better for high speed,
and more over the viscosity range is more then semi.

What oil have you being using before and have you had any trouble ?

Dealer should know exactly what oil your engine needs, and in your case I would leave it to them.
There is no leak issue between semi or fully, in rare cases it rather could
be an issue of viscosity.