It is not recomended to switch from a mineral-based oil to a synthetic on a motor that has been on mineral-based oil for a long time. Although the synthetic may be a better lubricant, the seals which have swelled up with the mineral-based oil will shrink when you use the synthetic causing the motor to leak. There are hybrid oils combining synthetic and mineral-based oils claiming to provide the best of both. Use at your own risk. Best advice is to stay with a branded oil like Valvoline and change it on a regular basis along with the oil filter. Never overfill, it causes leaks and excessive oil consumption. Don't forget all of the other procedures that are supposed to be done along with changing the motor oil like greasing the front suspension. Using a good, branded premium mineral-based oil is just fine for the PRV. It was designed and built to use this class of oils, any possible benefit from using synthetic will be very small and may cause you other problems. BTW synthetics are a lot more expensive and you are probably NOT looking to extend the service period to compensate (which is one of the benefits of using synthetics). David Teitelbaum vin 10757 --- In dmcnews@xxxxxxxxxxxxxxx, Faded N Jaded <fadednjaded@...> wrote: > > Dear fellow De Lorean owners, > > For years I have been using Valvoline 20-50 in my De Lorean. The engine has less than 20,000 miles. > > When our engines were selected for our cars I don't beleive that synthetic oils were available. Is there reason to believe that one of these synthetic oils will do a better job at protecting our engines or should I continue to use the same oil and the same weight that I have been using? > > If there is a good reason to switch to one of the synthetic oils, what weight do you suggest? > > What is your favorite oil? > > I will appreciate any thoughts on this. > > You may write me off list, if you wish. > > Faded > > [Non-text portions of this message have been removed] > ------------------------------------ To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnewsYahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/dmcnews/join (Yahoo! ID required) <*> To change settings via email: mailto:dmcnews-digest@xxxxxxxxxxxxxxx mailto:dmcnews-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/