Reply from jug is pretty accurate, except to the best of my knowledge (gained from Italian friends and Quattroroute magazine) that FIAT designed the diesel engines and GM the petrol motors. So, for instance, the 1.3MJT and 1.9MJT engines were disigned by FIAT and GM had the right to use them. However, the 105 version of the 1.3 will not be available to Vauxhall/Opel nor will the 190bhp version of the 1.9. GM, on the other hand has made certain petrol engines for FIAT group to use. The 2.2 JTS in the Alfa 159 is a GM design, as is the 3.2 V6 in other models such as the 166 and Brera. There has been some falling out as FIAT have told GM the 2.4 5-cyl diesel won't be made for them. Up till the agreement between them,the only diesels used by GM were the old 1.7 which has been around since the first of the front drive Cavaliers (as a 1.6), the 2.0 & 2.2 di s and the big old Isuzu which I think went in the Signum for a while. The reason with all those engines around that GM went to FIAT was because they were all rubbish. Not economical enough, poor performance and a general savageing by the press. jug, you were also right that the deal saved FIAT a lot of money and kept them from being taken over and probably broken up as a group. It may be interesting to note that GM will shortly have a new large diesel coming out and FIAT will have a 1.6. The business of component sharing is a complicated one and is very widespread. If you look back to the Alfa 164, FIAT Croma (mk1), Lancia Thema, and Saab 9000, they all had the same platform and basic structure, but with different engines and the new FIAT 500 shares its platform with the new Ford Ka, not to mention Ford using some diesels made by Citroen/Peugeot. Sorry this was a bit long, most of my replies are.