Hi, The best compromise is semi-synthetic oil, a few weeks ago I went into PartCo. they had semi-synthetic on special offer, buy one tub get one half-price, they may still be doing it. (you need 2 to fill the car) Fully synthetic is very fine and will find any leaks you may have, and drip on the garage floor, to be honest the DMC engine does not rev hard enough nor get hot enough to reap the benefits of fully synthetic oil, and it is pretty expensive especially if you are going to change it every 6-12 months. James RG