It is important to remember that with modern engines equipped with an automatic tensioner the belt size is crucial. We would recommend using the exact size the manufacturer dictates or at an absolute maximum, a belt within 2mm either way. Many tensioners work to small tolerences, and a few millimetres can be the difference between a flapping/vibrating belt that could part company from it's pulleys and become tangled with the cam belt, or an overtight tensioner that can potentially fail prematurely. Either way, a disaster. Commonly, most belts will have a size printed on the outer surface, if this is not visible, you should be able to find a size in the following catalogue. Once you have found your auxiliary / fan belt part number, make a note and enter it directly into our search box in the top left corner. If your search fails to turn up the exact size try shortening the number to increase the search results, ie 6pk1234 to 6pk123. If a 1233 exists then this should find it. eg; 6PK1750 equates to a Six rib belt with a circumference of 1750mm 10AV650 equates to a 'V' belt. 10mm in width and with a circumference of 650mm If in any doubt, do not hesitate to give us a call. | 
